[Federal Register Volume 87, Number 80 (Tuesday, April 26, 2022)]
[Rules and Regulations]
[Pages 24652-24749]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-08026]



[[Page 24651]]

Vol. 87

Tuesday,

No. 80

April 26, 2022

Part II





Department of Justice





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Bureau of Alcohol, Tobacco, Firearms, and Explosives





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27 CFR Parts 447, 478, and 479





Definition of ``Frame or Receiver'' and Identification of Firearms; 
Final Rule

Federal Register / Vol. 87 , No. 80 / Tuesday, April 26, 2022 / Rules 
and Regulations

[[Page 24652]]


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DEPARTMENT OF JUSTICE

Bureau of Alcohol, Tobacco, Firearms, and Explosives

27 CFR Parts 447, 478, and 479

[Docket No. 2021R-05F; AG Order No. 5374-2022]
RIN 1140-AA54


Definition of ``Frame or Receiver'' and Identification of 
Firearms

AGENCY: Bureau of Alcohol, Tobacco, Firearms, and Explosives; 
Department of Justice.

ACTION: Final rule.

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SUMMARY: The Department of Justice (``Department'') is amending Bureau 
of Alcohol, Tobacco, Firearms, and Explosives (``ATF'') regulations to 
remove and replace the regulatory definitions of ``firearm frame or 
receiver'' and ``frame or receiver'' because the current regulations 
fail to capture the full meaning of those terms. The Department is also 
amending ATF's definitions of ``firearm'' and ``gunsmith'' to clarify 
the meaning of those terms, and to provide definitions of terms such as 
``complete weapon,'' ``complete muffler or silencer device,'' ``multi-
piece frame or receiver,'' ``privately made firearm,'' and ``readily'' 
for purposes of clarity given advancements in firearms technology. 
Further, the Department is amending ATF's regulations on marking and 
recordkeeping that are necessary to implement these new or amended 
definitions.

DATES: This rule is effective August 24, 2022.

FOR FURTHER INFORMATION CONTACT: Vivian Chu, Office of Regulatory 
Affairs, Enforcement Programs and Services, Bureau of Alcohol, Tobacco, 
Firearms, and Explosives, U.S. Department of Justice, 99 New York Ave. 
NE, Washington, DC 20226; telephone: (202) 648-7070.

SUPPLEMENTARY INFORMATION:

I. Executive Summary
    A. Summary of the Regulatory Action
    B. Summary of Costs and Benefits
II. Background
    A. ATF's Application of the Definitions to Split Frames and 
Receivers
    B. Privately Made Firearms
    C. Advanced Notice of Proposed Rulemaking on Identification 
Markings Placed on Firearm Silencers and Firearm Mufflers
III. Notice of Proposed Rulemaking
    A. Definition of ``Firearm''
    B. Definition of ``Frame or Receiver''
    C. Definition of ``Readily''
    D. Definitions of ``Complete Weapon'' and ``Complete Muffler or 
Silencer Device''
    E. Definition of ``Privately Made Firearm''
    F. Definition of ``Importer's or Manufacturer's Serial Number''
    G. Definition of ``Gunsmith''
    H. Marking Requirements for Firearms
    I. Recordkeeping
    J. Record Retention
IV. Analysis of Comments and Department Responses for the Proposed 
Rule
    A. Issues Raised in Support of the Rule
    B. Issues Raised in Opposition to the Rule
V. Final Rule
    A. Definition of ``Firearm''
    B. Definition of ``Frame or Receiver''
    C. Definition of ``Readily''
    D. Definitions of ``Complete Weapon'' and ``Complete Muffler or 
Silencer Device''
    E. Definition of ``Privately Made Firearm''
    F. Definition of ``Importer's or Manufacturer's Serial Number''
    G. Definition of ``Gunsmith''
    H. Marking Requirements for Firearms
    I. Recordkeeping
    J. Record Retention
    K. Effect on Prior ATF Rulings and Procedures
    L. Severability
VI. Statutory and Executive Order Review
    A. Executive Orders 12866 and 13563
    B. Executive Order 13132
    C. Executive Order 12988
    D. Regulatory Flexibility Act
    E. Small Business Regulatory Enforcement Fairness Act of 1996
    F. Congressional Review Act
    G. Unfunded Mandates Reform Act of 1995
    H. Paperwork Reduction Act of 1995

I. Executive Summary

A. Summary of the Regulatory Action

    There are no statutory definitions for the terms ``frame'' or 
``receiver'' in the Gun Control Act of 1968 (``GCA'') or the National 
Firearms Act of 1934 (``NFA''). To implement these statutes, the terms 
``firearm frame or receiver'' and ``frame or receiver'' were defined in 
regulations to mean ``[t]hat part of a firearm which provides housing 
for the hammer, bolt or breechblock, and firing mechanism, and which is 
usually threaded at its forward portion to receive the barrel.'' 27 CFR 
478.11 (implementing GCA, Title I); 27 CFR 479.11 \1\ (implementing 
GCA, Title II). These definitions were meant to provide direction as to 
which portion of a weapon is the frame or receiver for purposes of 
licensing, serialization, and recordkeeping, thereby ensuring that a 
component necessary for the functioning of the weapon could be traced 
if later involved in a crime.
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    \1\ The definition of ``frame or receiver'' in section 479.11 
differs slightly from the definition in section 478.11 in that it 
omits an Oxford comma between ``bolt or breechblock'' and ``firing 
mechanism.''
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    However, a restrictive application of these definitions would not 
describe the frame or receiver of most firearms currently in 
circulation in the United States. Most modern weapon designs, including 
semiautomatic rifles and pistols with detachable magazines, have a 
split or multi-piece receiver where the relevant fire control 
components are housed by more than one part of the weapon (e.g., the 
upper receiver and lower receiver of an AR-15 rifle), or incorporate a 
striker to fire the weapon, rather than a hammer.
    In the past few years, some courts have treated the regulatory 
definition of ``firearm frame or receiver'' as inflexible when applied 
to the lower portion of the AR-15-type rifle, one of the most popular 
firearms in the United States. If broadly followed, that result could 
mean that as many as 90 percent of all firearms (i.e., with split 
frames or receivers, or striker-fired) in the United States would not 
have any frame or receiver subject to regulation. Furthermore, 
technological advances have also made it easier for companies to sell 
firearm parts kits, standalone frame or receiver parts, and easy-to-
complete frames or receivers to unlicensed persons, without maintaining 
any records or conducting a background check. These parts kits, 
standalone frame or receiver parts, or partially complete frames or 
receivers enable individuals to make firearms quickly and easily. Such 
privately made firearms (``PMFs''), when made for personal use, are not 
required by the GCA to have a serial number placed on the frame or 
receiver, making it difficult for law enforcement to determine where, 
by whom, or when they were manufactured, and to whom they were sold or 
otherwise transferred. Because of the difficulty with tracing illegally 
sold or distributed PMFs, those firearms are also commonly referred to 
as ``ghost guns.''
    For these many reasons, ATF is promulgating a rule that would bring 
clarity to the definition of ``frame or receiver'' by providing an 
updated, more comprehensive definition. On May 21, 2021, the Department 
published a Notice of Proposed Rulemaking (``NPRM'') in the Federal 
Register, 86 FR 27720, proposing to redefine the term ``frame or 
receiver'' as that which provides housing or a structure to hold or 
integrate one or more fire control components. In light of the comments 
received, this final rule revises the proposed definition of ``frame or 
receiver'' so that a ``frame'' is applicable to a handgun, and variants 
thereof, and a ``receiver'' is applicable to a rifle, shotgun, or 
projectile weapon other than a handgun, and variants thereof. Moreover, 
``frame or receiver'' will be defined to describe only a single part

[[Page 24653]]

that provides housing or a structure for one specific, primary fire 
control component of weapons that expel a projectile, or one specific, 
primary internal sound reduction component of firearm mufflers or 
silencers. The final rule also defines the meaning of ``variants'' and 
``variants thereof.'' The final rule provides detailed examples along 
with pictures identifying the frame or receiver of a variety of common 
models under the updated definition. The final rule also exempts from 
the new definitions and marking requirements existing split frame or 
receiver designs in which a part was previously classified by ATF as 
the firearm ``frame or receiver'' and provides examples and pictures of 
select exempted frames or receivers, such as AR-15/M-16 variant 
firearms. The only exception to ``grandfathering'' will be for 
partially complete, disassembled, or nonfunctional frames or receivers, 
including weapon or frame or receiver parts kits, that ATF did not 
classify as firearm ``frames or receivers'' as defined prior to this 
rule.
    The final rule also specifies, with more clarity and examples than 
the NPRM, how these terms apply to multi-piece frames or receivers 
(i.e., those that may be disassembled into multiple modular subparts), 
to firearm mufflers and silencers, to partially complete, disassembled, 
or nonfunctional frames or receivers, including frame or receiver parts 
kits, and to frames or receivers that are destroyed. The final rule 
also provides detailed examples of when such items are considered 
readily completed, assembled, restored, or otherwise ``converted'' to 
function as a frame or receiver. At the same time, the final rule makes 
clear that articles that have not yet reached a stage of manufacture 
where they are clearly identifiable as an unfinished component of a 
frame or receiver (e.g., unformed blocks of metal, liquid polymers, or 
other raw materials) are not frames or receivers.
    Consistent with the GCA, and to ensure proper licensing, marking, 
recordkeeping, and background checks with respect to certain weapon 
parts kits, the final rule adopts the proposed clarification of the 
term ``firearm'' to include weapon (e.g., pistol, revolver, rifle, or 
shotgun) parts kits that are designed to or may readily be completed, 
assembled, restored, or otherwise converted to expel a projectile by 
the action of an explosive. This rule also finalizes, with minor 
changes, the proposed definition of ``privately made firearm.'' It 
amends the regulations to require that all firearms privately 
manufactured or ``made'' by nonlicensees without identifying markings 
that are taken into inventory by licensees be identified (or marked) 
and recorded so that they may be traced by law enforcement through 
their records if they are later involved in crime. As with the NPRM, 
the final rule does not mandate unlicensed persons to mark their own 
PMFs for personal use, or when they occasionally acquire them for a 
personal collection or sell or transfer them from a personal collection 
to unlicensed in-State residents consistent with Federal, State, and 
local law.
    In addition, the rule finalizes the proposed amendments to the term 
``gunsmith'' to include persons who engage in the business of 
identifying firearms for nonlicensees, thus ensuring greater access to 
professional marking services for PMFs. The final rule clarifies the 
gunsmithing rules proposed in the NPRM by stating the following: (1) 
Licensed firearms dealers (in addition to licensed manufacturers and 
importers) may conduct same-day adjustments or repairs of all firearms, 
including PMFs, without taking them into inventory, provided they are 
returned to the person from whom they were received; (2) nonlicensees 
may mark PMFs for a licensee under the licensee's direct supervision; 
and (3) licensees may adopt an existing unique identification number 
previously placed on a PMF by a nonlicensee under certain conditions.
    In response to comments, the final rule permits licensed 
manufacturers to adopt the serial number and other identifying markings 
previously placed on a firearm without a variance from ATF, provided 
the firearm has not been sold, shipped, or otherwise disposed of to a 
person who is not a licensed manufacturer, superseding ATF Ruling 2009-
5. The rule permits licensed manufacturers to perform gunsmithing 
services on existing, marked firearms without marking or obtaining a 
marking variance, superseding ATF Ruling 2010-10. It also finalizes, 
with some modifications, the proposed definition of the term 
``importer's or manufacturer's serial number'' to help ensure that the 
serial number and associated identifying markings required to be placed 
on a firearm, including those placed on a PMF or an ATF-issued serial 
number,\2\ are considered the ``importer's or manufacturer's serial 
number'' protected by 18 U.S.C. 922(k), which prohibits possession or 
receipt of a firearm that has had the importer's or manufacturer's 
serial number removed, obliterated, or altered.
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    \2\ ATF occasionally issues serial numbers for placement on 
firearms in which the serial numbers were not originally placed, see 
26 U.S.C. 5842(b), or were accidentally removed, damaged, or worn 
due to routine use or other innocent reason.
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    The final rule adopts, with minor clarifying changes, the proposed 
clarifications to the marking and recordkeeping requirements for 
licensees. First, the rule finalizes the definitions for ``complete 
weapon'' and ``complete muffler or silencer device,'' and adds a new 
definition for ``multi-piece frame or receiver'' under the new 
definition of ``frame or receiver.'' The rule also specifies a 
reasonable time period in which a complete weapon or a complete muffler 
or silencer device, or the frame or receiver of a weapon or device 
(including a modular subpart of a multi-piece frame or receiver), must 
be marked with a serial number and other identifying information and 
recorded. Second, the rule finalizes the proposed updates to the 
information required to be marked on the frame or receiver, clarifies 
the meaning of the marking terms ``identify,'' ``legibly,'' and 
``conspicuously,'' and authorizes firearms licensees to adopt 
identifying markings in the manufacturing process. Third, the rule 
finalizes the proposal to require all licensees to consolidate their 
records of manufacture, acquisition, and disposition of firearms, and 
to eliminate duplicate recordkeeping entries. Fourth, with respect to 
parts defined as firearm mufflers or silencers, which are difficult to 
mark and record, this rule finalizes with minor clarifying changes the 
proposed amendments that allow for them to be transferred between 
licensees qualified under the NFA for purposes of further manufacture 
or repair of complete devices without immediately marking and 
registering them in the National Firearms Registration and Transfer 
Record (``NFRTR''). Fifth, the rule finalizes with minor clarifying 
changes the proposed amendments that set forth the process by which 
persons may voluntarily seek a determination from ATF on whether an 
item or kit they wish to manufacture or possess is a firearm or armor 
piercing ammunition subject to marking, recordkeeping, and other 
applicable Federal laws and regulations. These amendments to the 
regulations will help ensure that firearms can be traced efficiently 
and effectively by law enforcement through the records of licensees, 
and help prevent the acquisition of easy-to-complete firearms by 
prohibited persons and terrorists.
    Lastly, the rule finalizes with minor changes the proposed 
requirement that all licensees retain their records until the business 
or licensed activity is discontinued, either on paper or in an

[[Page 24654]]

electronic format approved by the Director of ATF (``Director''), at 
the business or collection premises readily accessible for inspection. 
This includes authorization of licensees to store their ``closed out'' 
paper records and forms older than 20 years at a separate warehouse, 
which would be considered part of the business or collection premises 
for this purpose and subject to inspection. These provisions will 
enhance public safety by ensuring that acquisition and disposition 
records of all active licensees are not destroyed after 20 years and 
will remain available to law enforcement for tracing purposes.

B. Summary of Costs and Benefits

    The final rule clarifies which firearms are subject to regulation 
under the GCA and NFA and associated licensing, marking, and 
recordkeeping requirements. The rule requires persons who engage in the 
business of dealing in weapon and frame or receiver parts kits defined 
as firearms to be licensed, mark the frames or receivers within such 
kits with serial numbers and other marks of identification, and 
maintain records of their acquisition and disposition. The provisions 
of these statutes and implementing regulations are designed to increase 
public safety by, among other things, preventing prohibited persons 
from acquiring firearms and allowing law enforcement to trace firearms 
involved in crime.
    To minimize disruption and cost to the licensed firearms industry 
as much as possible, and in keeping with the public safety goals of the 
rule, this rule grandfathers existing complete frame or receiver 
designs previously determined by the Director to be the firearm ``frame 
or receiver'' of a given weapon. It does not grandfather partially 
complete, disassembled, or nonfunctional frames or receivers, including 
weapon or frame or receiver parts kits, that ATF did not classify as 
firearm ``frames or receivers'' as previously defined. ATF estimates 
that the 7 percent annualized cost of this rule is $14.3 million.

II. Background

    The Attorney General is responsible for enforcing the Gun Control 
Act of 1968, as amended, and the National Firearms Act of 1934, as 
amended.\3\ This responsibility includes the authority to promulgate 
regulations necessary to enforce the provisions of the GCA and NFA. See 
18 U.S.C. 926(a); 26 U.S.C. 7801(a)(2)(A), 7805(a).\4\ Congress and the 
Attorney General have delegated the responsibility for administering 
and enforcing the GCA and NFA to the Director of ATF, subject to the 
direction of the Attorney General and the Deputy Attorney General. See 
26 U.S.C. 7801(a)(2); 28 U.S.C. 599A(b)(1), (c)(1); 28 CFR 0.130(a)(1)-
(2); T.D. Order No. 221(2)(a), (d), 37 FR 11696-97 (June 10, 1972). 
Accordingly, the Department and ATF have promulgated regulations to 
implement the GCA and NFA. See 27 CFR parts 478, 479.
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    \3\ NFA provisions still refer to the ``Secretary of the 
Treasury.'' See generally 26 U.S.C. ch. 53. However, the Homeland 
Security Act of 2002, Public Law 107-296, 116 Stat. 2135, 
transferred the functions of ATF from the Department of the Treasury 
to the Department of Justice, under the general authority of the 
Attorney General. 26 U.S.C. 7801(a)(2); 28 U.S.C. 599A(c)(1). Thus, 
for ease of reference, this final rule refers to the Attorney 
General throughout.
    \4\ See also footnote 82, infra, for specific grants of 
rulemaking authority.
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    On May 21, 2021, the Department published in the Federal Register a 
Notice of Proposed Rulemaking (``NPRM'') entitled ``Definition of 
`Frame or Receiver' and Identification of Firearms,'' 86 FR 27720, 
proposing changes to various regulations in 27 CFR parts 447, 478, and 
479. The comment period for the proposed rule concluded on August 19, 
2021, and ATF received 290,031 comments.
    The NPRM provided a comprehensive explanation of the passage of the 
Federal Firearms Act of 1938 (``FFA''), Public Law 75-785, 52 Stat. 
1250, its repeal, and the subsequent legislative history and context 
leading to Congress's passage of the GCA in 1968, as well as the 
promulgation of the definitions for ``frame or receiver'' that ATF and 
the firearms industry have relied on for more than 50 years.\5\ 86 FR 
at 27720-21. The GCA at 18 U.S.C. 921(a)(3) defines the term 
``firearm'' to include not only a weapon that will, is designed to, or 
may readily be converted to expel a projectile, but also the ``frame'' 
or ``receiver'' of any such weapon. 18 U.S.C. 921(a)(3)(A), (B). 
Because frames or receivers are included in the definition of 
``firearm,'' any person who engages in the business of manufacturing, 
importing, or dealing in frames or receivers must obtain a license from 
ATF. 18 U.S.C. 922(a)(1)(A), 923(a). Each licensed manufacturer or 
importer must ``identify by means of a serial number engraved or cast 
on the receiver or frame of the weapon, in such manner as the Attorney 
General shall by regulations prescribe, each firearm imported or 
manufactured by such importer or manufacturer.'' \6\ 18 U.S.C. 923(i); 
see 27 CFR 478.92, 479.102. Licensed manufacturers and importers must 
also maintain permanent records of production or importation, as well 
as their receipt, sale, or other disposition of firearms, including 
frames or receivers. 18 U.S.C. 923(g)(1)(A); 27 CFR 478.122, 478.123.
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    \5\ The Omnibus Crime Control and Safe Streets Act of 1968 
repealed the FFA and was then incorporated into and expanded by the 
GCA. Public Law 90-351, secs. 906-07, 82 Stat. 197, 234-35 (1968); 
Public Law 90-618, 82 Stat. 1213 (1968).
    \6\ Additionally, a firearm frame or receiver that is not a 
component part of a complete weapon at the time it is sold, shipped, 
or disposed of must be identified in the manner prescribed with a 
serial number and all of the other required markings. 27 CFR 
478.92(a)(2), 479.102(e); ATF Rul. 2012-1.
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    The GCA does not define the terms ``frame'' or ``receiver'' to 
implement the statute, but frames or receivers are the primary 
structural components of a firearm to which fire control components are 
attached.\7\ After the GCA was enacted, the terms ``firearm frame or 
receiver'' and ``frame or receiver'' were defined as ``that part of a 
firearm which provides housing for the hammer, bolt or breechblock, and 
firing mechanism, and which is usually threaded at its forward portion 
to receive the barrel.'' 27 CFR 478.11 (implementing GCA, Title I); \8\ 
27 CFR 479.11 (implementing GCA, Title II).\9\ The intent in 
promulgating these definitions was to inform the public and industry as 
to which portion of a firearm was the frame or receiver for purposes of 
licensing, serialization, and recordkeeping, thus ensuring that a 
necessary component of the weapon could be traced if later involved in 
a crime.
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    \7\ See Webster's Third New International Dictionary 902, 1894 
(1971) (a ``frame'' is ``the basic unit of a handgun which serves as 
a mounting for the barrel and operating parts of the arm''; 
``receiver'' means ``the metal frame in which the action of a 
firearm is fitted and to which the breech end of the barrel is 
attached''); John Olson, Olson's Encyclopedia of Small Arms 72 
(1985) (the term ``frame'' means ``the basic structure and principal 
component of a firearm''); Steindler's New Firearms Dictionary, p. 
209 (1985) (``receiver'' means ``that part of a rifle or shotgun . . 
. that houses the bolt, firing pin, mainspring, trigger group, and 
magazine or ammunition feed system. The barrel is threaded into the 
somewhat enlarged forward part of the receiver, called the receiver 
ring. At the rear of the receiver, the butt or stock is fastened. In 
semiautomatic pistols, the frame or housing is sometimes referred to 
as the receiver'').
    \8\ See 33 FR 18558 (Dec. 14, 1968) (formerly 26 CFR 178.11).
    \9\ See 36 FR 14257 (Aug. 3, 1971) (formerly 26 CFR 179.11).
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    The NPRM discussed that at the time the regulatory definitions were 
promulgated, single-framed firearms such as revolvers and break-open 
shotguns were far more prevalent for civilian (i.e., not military or 
law enforcement) use in the United States than split receiver weapons, 
such as semiautomatic rifles and pistols with detachable magazines. 
Single-framed firearms incorporate the hammer, bolt or breechblock, and 
firing mechanism within the same housing. 86 FR at

[[Page 24655]]

27721. Over time, split receiver firearms became popular for civilian 
use, such as the AR-15 semiautomatic rifle (upper receiver and lower 
receiver), Glock semiautomatic pistol (upper slide assembly and lower 
grip module), and Sig Sauer P320 pistol (M17/18 as adopted by the U.S. 
military) (upper slide assembly, chassis, and lower grip module). And 
more firearm manufacturers began incorporating a striker-fired 
mechanism, rather than a ``hammer,'' in the firing design, such as in 
the Glock pistol. Id.

A. ATF's Application of the Definitions to Split Frames and Receivers

    The NPRM explained that ATF's regulatory definitions of ``frame or 
receiver'' do not expressly capture these types of firearms (i.e., 
split frames or receivers) that now constitute the majority of firearms 
in the United States.\10\ However, ATF's position has long been that 
the weapon ``should be examined with a view toward determining if 
[either] the upper or lower half of the receiver more nearly fits the 
legal definition of `receiver,' '' and more specifically, for 
machineguns, whether the upper or lower portion has the ability to 
accept machinegun parts.<SUP>11 12</SUP> The NPRM listed the variety of 
factors ATF has considered when making determinations for firearm 
classifications under the GCA and NFA regarding which part of a firearm 
is the frame or receiver, given that neither a split nor a multi-piece 
receiver has a portion of its design that falls within the precise 
wording of the existing regulatory definition. 86 FR at 27721.
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    \10\ United States v. Rowold, 429 F. Supp. 3d 469 (N.D. Ohio 
2019), Testimony of ATF Firearms Enforcement Officer Daniel Hoffman 
at Doc. No. 60, Hrg. Tr., Page ID 557 (approximately 10 percent of 
currently manufactured firearms in the United States include at 
least three components in the frame or receiver definition), and 
Defense Expert Daniel O'Kelly at Doc. No. 60, Hrg. Tr., Page ID 482 
(``90 some percent of [semiautomatic pistols] do not have a part 
which has more than one of these four elements in it and, therefore, 
don't qualify, according to the definition in the CFR.'').
    \11\ ATF Internal Revenue Service Memorandum #21208 (Mar. 1, 
1971) (lower portion of the M-16 is the frame or receiver because it 
comes closest to meeting the definition of frame or receiver in 26 
CFR 178.11 (now 27 CFR 478.11), and is the receiver of a machinegun 
as defined in the NFA); ATF Memorandum #22334 (Jan. 24, 1977) (upper 
half of the FN-FAL rifle is the frame or receiver because it was 
designed to accept the components that allow fully automatic fire). 
The ability to accept machinegun parts is considered because both 
the GCA and the NFA regulate machinegun receivers as 
``machineguns.'' See 18 U.S.C. 921(a)(23); 26 U.S.C. 5845(b) (``The 
term [``machinegun''] shall also include the frame or receiver of 
any such weapon [which shoots is designed to shoot, or can be 
readily restored to shoot, automatically more than one shot, without 
manual reloading, by a single function of the trigger].'').
    \12\ Regulations implementing the relevant statutes spell the 
term ``machine gun'' rather than ``machinegun.'' E.g., 27 CFR 
478.11, 479.11. For convenience, this rule uses ``machinegun,'' 
except when quoting a source to the contrary.
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    Indeed, the current definitions were never intended, or understood, 
to be exhaustive. The Department discussed in the NPRM the existing law 
and congressional intent recognizing that the definition of ``frame or 
receiver'' need not be limited to a strict application of the 
regulation. Id. at 27721-22. At the time the current definitions were 
adopted, there were numerous models of firearms that did not contain a 
part that fully met the regulatory definition of ``frame or receiver,'' 
such as the Colt 1911, FN-FAL, and the AR-15/M-16, all of which were 
originally manufactured almost exclusively for military use. ATF has 
long applied the factors stated in the NPRM when determining which 
component of those weapons qualifies as the frame or receiver.\13\
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    \13\ See footnote 11, supra.
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    While ATF for decades has classified the lower receiver of the AR-
15 rifle as a ``frame or receiver,'' some courts recently have treated 
the regulatory definition as inflexible when applied to the lower 
portion of the AR-15-type rifle, which is the semiautomatic version of 
the M-16-type machinegun originally designed for the U.S. military. 
That was because those courts have read the regulatory definition to 
mean that the lower portion of the AR-15 is not a ``frame or 
receiver,'' as it provides housing only for the hammer and firing 
mechanism, not the bolt or breechblock. See United States v. Rowold, 
429 F. Supp. 3d 469, 475-76 (N.D. Ohio 2019). (``The language of the 
regulatory definition in Sec.  478.11 lends itself to only one 
interpretation: Namely, that under the GCA, the receiver of a firearm 
must be a single unit that holds three, not two components: (1) The 
hammer, (2) the bolt or breechblock, and (3) the firing mechanism.''); 
see also United States v. Roh, 8:14-cr-00167-JVS, Minute Order p. 6 
(C.D. Cal. July 27, 2020); United States v. Jimenez, 191 F. Supp. 3d 
1038, 1041 (N.D. Cal. 2016).
    The NPRM explained that, if broadly followed, these courts' 
interpretation of ATF's regulations could mean that as many as 90 
percent of all firearms now in the United States would not have any 
frame or receiver subject to regulation under the current 
definitions.\14\ Those firearms would include numerous widely available 
models, such as Glock-type and Sig Sauer P320 \15\ pistols, that do not 
utilize a hammer--a named component in the existing regulatory 
definition--in the firing sequence. Such a narrow interpretation of 
what constitutes a frame or receiver would allow persons to avoid 
obtaining a license to engage in the business of manufacturing or 
importing upper or lower frames or receivers, which would further allow 
those persons to avoid the GCA's marking, recordkeeping, and background 
check requirements pertaining to upper or lower frames or receivers. 
See 86 FR at 27722. In turn, prohibited persons may more easily and 
without a background check acquire upper and lower receivers that can 
quickly be assembled into semiautomatic weapons.\16\ Moreover, law 
enforcement's ability to trace semiautomatic firearms later used in 
crime would be severely impeded if no portion of split or multi-piece 
frames or receivers were subject to any existing regulations as 
described. This result would undermine the intent of Congress in 
requiring the frame or receiver of every firearm to be identified, see 
18 U.S.C. 923(i), and regulated as a firearm, see 18 U.S.C. 
921(a)(3)(B).
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    \14\ See footnote 10, supra.
    \15\ The United States military services have adopted variants 
of the Sig Sauer P320 as their official sidearm, and are in the 
process of purchasing up to 500,000 of these striker-fired pistols. 
Matthew Cox & Hope Hodge Seck, Army Picks Sig Sauer's P320 Handgun 
to Replace M9 Service Pistol, Military.com (Jan. 19, 2017), 
available at https://www.military.com/daily-news/2017/01/19/army-picks-sig-sauer-replace-m9-service-pistol.html (last visited Mar. 
22, 2022); Jared Keller, Every U.S. military branch is about to get 
its hands on the Army's new sidearm of choice, Taskandpurpose.com 
(Nov. 18, 2020), available at https://taskandpurpose.com/military-tech/modular-handgun-system-fielding (last visited Mar. 22, 2022) 
(Sig Sauer delivered its 200,000th P320-variant pistol to the 
military despite the obstacles posed by the novel coronavirus).
    \16\ See Jake Bleiberg & Stefanie Dazio, Design of AR-15 could 
derail charges tied to popular rifle, APnews.com (Jan. 13, 2020), 
available at https://apnews.com/article/396bbedbf4963a28bda99e7793ee6366 (last visited Mar. 22, 2022); Dan 
Morse & Jasmine Hilton, Magruder [High School] student bought `ghost 
gun' components online before wounding classmate, Wash. Post (Jan. 
24, 2022), available at https://www.washingtonpost.com/dc-md-va/2022/01/24/magruder-shooting-teen-jailed (last visited Mar. 22, 
2022).
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B. Privately Made Firearms

    The NPRM explained that technological advances have also made it 
easier for companies to sell firearm parts kits, standalone frame or 
receiver parts, or partially complete frames or receivers to unlicensed 
persons, posing significant challenges to the regulation of frames and 
receivers and enabling prohibited individuals to easily make firearms 
at home, especially if aided by personally owned equipment or 3D 
printers. These privately made firearms, commonly referred to as 
``ghost guns,'' are not required by the GCA to have a

[[Page 24656]]

serial number placed on the frame or receiver when made for personal 
use. When PMFs are relinquished by their owners, enter commerce, and 
are later recovered and submitted for tracing, the absence of markings 
on PMFs makes it extremely difficult for law enforcement to determine 
where, by whom, or when they were manufactured, and to whom they were 
sold or otherwise disposed.
    The NPRM discussed the substantial increase in the number of PMFs 
recovered from crime scenes throughout the country in recent years.\17\ 
From January 1, 2016, through December 31, 2021, there were 
approximately 45,240 suspected PMFs reported to ATF as having been 
recovered by law enforcement from potential crime scenes, including 692 
homicides or attempted homicides (not including suicides), and which 
ATF attempted to trace. Broken down by calendar year, the total annual 
numbers of suspected PMFs recovered show significant proliferation over 
the past six years: 2016: 1,758; 2017: 2,552; 2018: 3,960; 2019: 7,517; 
2020: 10,109; 2021: 19,344.<SUP>18 19</SUP>
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    \17\ 86 FR at 27722 n.17. See also Erik von Ancken, Untraceable 
`Ghost Guns' sold across Central Florida, WKMG-TV Orlando (Nov. 15, 
2016), available at https://www.clickorlando.com/getting-results/2016/11/15/untraceable-ghost-guns-sold-across-central-florida (last 
visited Mar. 22, 2022); Nicholas J. Simons, Ghost Guns: A Haunting 
New Reality, Rockefeller Institute of Justice (2021), available at 
https://rockinst.org/wp-content/uploads/2021/04/210413-Ghost-Guns-web.pdf (last visited Mar. 22, 2022); Travis Taniguchi et al., The 
Proliferation of Ghost Guns: Regulation Gaps and Challenges for Law 
Enforcement, National Police Foundation (2021), available at https://www.policefoundation.org/wp-content/uploads/2021/08/NPF_The-Proliferation-of-Ghost-Guns_Final_2021.pdf (last visited Mar. 22, 
2022); Shanzeh Ahmad & Jeremy Gorner, `We're seeing an explosion:' 
Sheriff Tom Dart, state Sen. Jacqueline Collins take aim at ghost 
guns, propose legislation to ban the untraceable weapons, Chi. Trib. 
(Oct. 14, 2021), available at https://www.chicagotribune.com/news/breaking/ct-cook-county-sheriff-dart-ghost-gun-legislation-20211014-whvwjv5aangmtaje27gpllqtvu-story.html (last visited Mar. 22, 2022); 
Brian X. McCrone, `3 Pipes Turned into a Shotgun': Nearly 1-in-10 
Guns Seized in Philly Are Homemade, NBC10 Philadelphia (Oct. 7, 
2021), available at https://www.nbcphiladelphia.com/news/local/three-metal-pipes-turned-into-a-shotgun-nearly-1-in-10-guns-seized-in-philly-are-homemade/2983066 (last visited Mar. 22, 2022); Kevin 
Rector, LAPD declares `ghost guns' an `epidemic,' citing 400% 
increase in seizures, L.A. Times (Oct. 15, 2021), available at 
https://www.latimes.com/california/story/2021-10-15/lapd-says-ghost-guns-an-epidemic-with-seizures-up-400-since-2017 (last visited Mar. 
22, 2022); Glenn Thrush, `Ghost Guns': Firearm Kits Bought Online 
Fuel Epidemic of Violence, N.Y. Times (Nov. 14, 2021), available at 
https://www.nytimes.com/2021/11/14/us/ghost-guns-homemade-firearms.html (last visited Mar. 22. 2022).
    \18\ Source: ATF Office of Strategic Intelligence and 
Information. These numbers (as of January 21, 2022) are likely far 
lower than the actual number of PMFs recovered from crime scenes 
because some law enforcement departments incorrectly trace some PMFs 
as commercially manufactured firearms, or may not see a need to use 
their resources to attempt to trace firearms with no serial numbers 
or other identifiable markings. The term ``suspected PMF'' is used 
because of the difficulty of getting law enforcement officials to 
uniformly enter PMF trace information into ATF's electronic tracing 
system (``eTrace''), resulting in reporting inconsistencies of PMFs 
involved in crime. For example, often PMFs resemble commercially 
manufactured firearms, or incorporate parts from commercially 
manufactured firearms bearing that manufacturer's name, so some 
firearms suspected of being PMFs were entered into eTrace using a 
commercial manufacturer's name rather than as one privately made by 
individuals. The term ``potential crime scenes'' is used because ATF 
does not know if the firearm being traced by the law enforcement 
agency was found at a crime scene as opposed to one recovered by law 
enforcement that had been stolen or otherwise not from the scene of 
a crime. This is because the recovery location or correlated crime 
is not always communicated by the agency to ATF in the tracing 
process.
    \19\ The total number of suspected PMFs is greater than the 
23,906 originally queried and reported as of March 4, 2021, in the 
NPRM, 86 FR at 27722-23, due, not only to the addition of CY 2021 
data, but also to traces being updated with more specificity 
regarding the firearm description since that date, and the inclusion 
of all suspected PMFs recovered within this time frame regardless of 
when the trace was entered.
[GRAPHIC] [TIFF OMITTED] TR26AP22.000

    Numerous criminal cases have been brought by the Department to 
counter the illegal trafficking of unserialized privately completed and 
assembled weapons, the possession of such

[[Page 24657]]

weapons by prohibited persons, and other related Federal crimes.\20\
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    \20\ 86 FR 27723 n.19. See also Dark Web Gun Trafficker from 
Nevada County Pleads Guilty to Unlawful Dealing in Firearms, DOJ/OPA 
(June 22, 2018), available at https://www.justice.gov/usao-edca/pr/dark-web-gun-trafficker-nevada-county-pleads-guilty-unlawful-dealing-firearms; Burlington Man Pleads Guilty to Ammunition Charge, 
DOJ/OPA (Dec. 12, 2018), available at https://www.justice.gov/usao-ma/pr/burlington-man-pleads-guilty-ammunition-charge; Burlington Man 
Sentenced For Ammunition Charge, DOJ/OPA (Mar. 19, 2019), available 
at https://www.justice.gov/usao-ma/pr/burlington-man-sentenced-ammunition-charge; Indiana Residents Indicted on Terrorism and 
Firearms Charges, DOJ/OPA (July 11, 2019), available at https://www.justice.gov/opa/pr/indiana-residents-indicted-terrorism-and-firearms-charges; Las Vegas Man Charged For Illegally Engaging In 
The Business Of Manufacturing Machine Guns Without A License, DOJ/
OPA (Sept. 4, 2019), available at https://www.justice.gov/usao-nv/pr/las-vegas-man-charged-illegally-engaging-business-manufacturing-machine-guns-without; Two Stockton Residents Sentenced for Firearms 
Offenses, DOJ/OPA (Nov. 21, 2019), available at https://www.justice.gov/usao-edca/pr/two-stockton-residents-sentenced-firearms-offenses; Denver Gang Member Sentenced To Over 15 Years In 
Federal Prison For Making And Selling Dozens Of High Powered Guns, 
Including Machine Guns And Silencers, DOJ/OPA (Nov. 22, 2019), 
available at https://www.justice.gov/usao-co/pr/denver-gang-member-sentenced-over-15-years-federal-prison-making-and-selling-dozens-high; Cedar Rapids Man Pleads Guilty to Drug Trafficking and 
Possessing Machineguns and a Pipe Bomb, DOJ/OPA (Jan. 21, 2020), 
available at https://www.justice.gov/usao-ndia/pr/cedar-rapids-man-pleads-guilty-drug-trafficking-and-possessing-machineguns-and-pipe; 
Indictment Charges 15 Members of a Los Angeles Drug Trafficking Ring 
that Distributed Heroin, Methamphetamine and Cocaine, DOJ/OPA (Feb. 
12, 2020), available at https://www.justice.gov/usao-cdca/pr/indictment-charges-15-members-los-angeles-drug-trafficking-ring-distributed-heroin; Two Queens Men Charged After Buying Three 
Illegally Defaced Firearms and Two Assault Rifles, DOJ/OPA (May 13, 
2020), available at https://www.justice.gov/usao-edny/pr/two-queens-men-charged-after-buying-three-illegally-defaced-firearms-and-two-assault; Second Defendant Charged with Murder in New Indictment in 
Case of Man Found Dead in Pacific Ocean after Being Shot on a Boat, 
DOJ/OPA (June 25, 2020), available at https://www.justice.gov/usao-cdca/pr/second-defendant-charged-murder-new-indictment-case-man-found-dead-pacific-ocean-after; Fishers residents indicted on 
terrorism and firearms charges, DOJ/OPA (July 12, 2019), available 
at https://www.justice.gov/usao-sdin/pr/fishers-residents-indicted-terrorism-and-firearms-charges; Outlaws Motorcycle Club Regional 
President Pleads Guilty to Firearms Charges, DOJ/OPA (July 15, 
2020), available at https://www.justice.gov/usao-ma/pr/outlaws-motorcycle-club-regional-president-pleads-guilty-firearms-charges; 
Sun Valley Man Indicted on Federal Narcotics Charges and Weapons 
Offenses, including Possession of Ghost Gun and Grenade Launcher, 
DOJ/OPA (July 23, 2020), available at https://www.justice.gov/usao-cdca/pr/sun-valley-man-indicted-federal-narcotics-charges-and-weapons-offenses-including; Seven Defendants Arrested and Charged in 
Conspiracy to Possess and Carry Firearms in Furtherance of Drug 
Trafficking, DOJ/OPA (Sept. 3, 2020), available at https://www.justice.gov/usao-dc/pr/seven-defendants-arrested-and-charged-conspiracy-possess-and-carry-firearms-furtherance; Takedown 
Completes Arrests of 15 Alleged Drug Traffickers in Syracuse Area, 
DOJ/OPA (Sept. 17, 2020), available at https://www.justice.gov/usao-ndny/pr/takedown-completes-arrests-15-alleged-drug-traffickers-syracuse-area; Three Members of Gardena Street Gang Charged in 
Federal Racketeering Case Alleging Murder of Man Outside His Home, 
DOJ/OPA (Dec. 2, 2020), available at https://www.justice.gov/usao-cdca/pr/three-members-gardena-street-gang-charged-federal-racketeering-case-alleging-murder-man; Syracuse Man Pleads Guilty to 
Brokering Illegal Gun Sales, DOJ/OPA (Dec. 9, 2020), available at 
https://www.justice.gov/usao-ndny/pr/syracuse-man-pleads-guilty-brokering-illegal-gun-sales; Gang Member Sentenced to More Than 7 
Years in Prison for Gun and Drug Offenses, DOJ/OPA (Feb. 17, 2021), 
available at https://www.justice.gov/usao-ct/pr/gang-member-sentenced-more-7-years-prison-gun-and-drug-offenses; Man Sentenced 
for Attempting to Board International Flight with a Loaded Firearm, 
DOJ/OPA (Mar. 12, 2021), available at https://www.justice.gov/usao-sdca/pr/man-sentenced-attempting-board-international-flight-loaded-firearm; Vacaville Man Sentenced to over 4 Years in Prison for 
Unlawfully Possessing Ammunition as a Felon, DOJ/OPA (May 4, 2021), 
available at https://www.justice.gov/usao-edca/pr/vacaville-man-sentenced-over-4-years-prison-unlawfully-possessing-ammunition-felon; Big Island man arrested on methamphetamine and firearm 
charges, DOJ/OPA (May 18, 2021), available at https://www.justice.gov/usao-hi/pr/big-island-man-arrested-methamphetamine-and-firearm-charges; Fresno Gang Member Faces Federal Firearms 
Charge, DOJ/OPA (June 3, 2021), available at https://www.justice.gov/usao-edca/pr/fresno-gang-member-faces-federal-firearms-charge; Temple Hills Man Sentenced To Three And A Half 
Years In Federal Prison For Trafficking Of Ghost Guns, DOJ/OPA (June 
4, 2021), available at https://www.justice.gov/usao-md/pr/temple-hills-man-sentenced-three-and-half-years-federal-prison-trafficking-ghost-guns; Septuagenarian charged with manufacturing ``ghost 
guns'', DOJ/OPA (June 15, 2021), available at https://www.justice.gov/usao-sdtx/pr/septuagenarian-charged-manufacturing-ghost-guns; Convicted Gun Trafficker Pleads Guilty to Firearms 
Charges, DOJ/OPA (June 22, 2021), available at https://www.justice.gov/usao-ndny/pr/convicted-gun-trafficker-pleads-guilty-firearms-charges; Barnstable Man Charged with Firearm Trafficking, 
DOJ/OPA (June 22, 2021), available at https://www.justice.gov/usao-ma/pr/barnstable-man-charged-firearm-trafficking; Laplace Man Pleads 
Guilty to Being Felon in Possession of Ammunition, DOJ/OPA (June 25, 
2021), available at https://www.justice.gov/usao-edla/pr/laplace-man-pleads-guilty-being-felon-possession-ammunition; Felon Pleads 
Guilty to Possession of Ghost Guns and Conspiracy to Commit Wire 
Fraud, DOJ/OPA (June 28, 2021), available at https://www.justice.gov/usao-md/pr/felon-pleads-guilty-possession-ghost-guns-and-conspiracy-commit-wire-fraud; Syracuse Man Sentenced to 
Seven Years in Federal Prison for Brokering Illegal Gun Sales, DOJ/
OPA (July 8, 2021), available at https://www.justice.gov/usao-ndny/pr/syracuse-man-sentenced-seven-years-federal-prison-brokering-illegal-gun-sales; Federal Drug and Gun Charges Brought Against 
Fresno Man Accused of Dealing Fentanyl, DOJ/OPA (July 15, 2021), 
available at https://www.justice.gov/usao-edca/pr/federal-drug-and-gun-charges-brought-against-fresno-man-accused-dealing-fentanyl; 
Vineland Boys Gang Member Sentenced to 31 Years in Federal Prison 
for Racketeering Conspiracy, Attempted Murder of Rival Gangsters, 
DOJ/OPA (July 22, 2021), available at https://www.justice.gov/usao-cdca/pr/vineland-boys-gang-member-sentenced-31-years-federal-prison-racketeering-conspiracy; Hartford Man Charged with Illegally 
Possessing Firearm and Ammunition, DOJ/OPA (July 23, 2021), 
available at https://www.justice.gov/usao-ct/pr/hartford-man-charged-illegally-possessing-firearm-and-ammunition; Philadelphia 
Man Arrested on Murder-For-Hire Charges; Attempted Homicide in 
Southwest Philadelphia Thwarted, DOJ/OPA (July 26, 2021), available 
at https://www.justice.gov/usao-edpa/pr/philadelphia-man-arrested-murder-hire-charges-attempted-homicide-southwest-philadelphia; 
Rensselaer County Felon Sentenced to 30 Months on Firearms 
Convictions, DOJ/OPA (Aug. 10, 2021), available at https://www.justice.gov/usao-ndny/pr/rensselaer-county-felon-sentenced-30-months-firearms-convictions; Three East Bay Men Charged With 
Conspiracy To Traffic Firearms, DOJ/OPA (Aug. 16, 2021), available 
at https://www.justice.gov/usao-ndca/pr/three-east-bay-men-charged-conspiracy-traffic-firearms; Raleigh Felon Sentenced After Pulling a 
Firearm on Officers During a Drug Investigation, DOJ/OPA (Aug. 17, 
2021), available at https://www.justice.gov/usao-ednc/pr/raleigh-felon-sentenced-after-pulling-firearm-officers-during-drug-investigation; Buffalo Man Arrested, Charged With Manufacturing 
Ghost Guns, DOJ/OPA (Aug. 20, 2021), available at https://www.justice.gov/usao-wdny/pr/buffalo-man-arrested-charged-manufacturing-ghost-guns; Montgomery County Man Sentenced to 30 
Months for Unlawfully Selling ``Ghost Guns'', DOJ/OPA (Sept. 2, 
2021), available at https://www.justice.gov/usao-ndny/pr/montgomery-county-man-sentenced-30-months-unlawfully-selling-ghost-guns; Three 
South Lake Tahoe Residents Charged with Drug Trafficking and Texas 
Man Charged with Trafficking Firearms, DOJ/OPA (Aug. 23, 2021), 
available at https://www.justice.gov/usao-edca/pr/three-south-lake-tahoe-residents-charged-drug-trafficking-and-texas-man-charged; New 
Mexico Man Who Sold `Ghost Guns' Indicted, DOJ/OPA (Sept. 8, 2021), 
available at https://www.justice.gov/usao-ndtx/pr/new-mexico-man-who-sold-ghost-guns-indicted; Fresno Men Indicted for Being 
Previously Convicted of Violent Crimes in Possession of Firearm and 
Ammunition, DOJ/OPA (Sept. 16, 2021), available at https://www.justice.gov/usao-edca/pr/fresno-men-indicted-being-previously-convicted-violent-crimes-possession-firearm-and; Connecticut Man 
Sentenced for Firearm Trafficking, DOJ/OPA (Sept. 16, 2021), 
available at https://www.justice.gov/usao-ma/pr/connecticut-man-sentenced-firearm-trafficking; Two Defendants Indicted For Oahu Game 
Room Robbery, Drug Trafficking, and ``Ghost Gun'' Possession, DOJ/
OPA (Sept. 17, 2021), available at https://www.justice.gov/usao-hi/pr/two-defendants-indicted-oahu-game-room-robbery-drug-trafficking-and-ghost-gun-possession; D.C. Felon Sentenced to 30 Months In 
Federal Prison For Illegal Possession Of A .40 Caliber ``Ghost Gun'' 
Firearm And 10 Rounds Of Ammunition, DOJ/OPA (Sept. 24, 2021), 
available at https://www.justice.gov/usao-md/pr/dc-felon-sentenced-30-months-federal-prison-illegal-possession-40-caliber-ghost-gun; 
Convicted Felon Sentenced for Narcotics Trafficking and 
Manufacturing ``Ghost Guns'', DOJ/OPA (Sept. 24, 2021), available at 
https://www.justice.gov/usao-edva/pr/convicted-felon-sentenced-narcotics-trafficking-and-manufacturing-ghost-guns; Two District Men 
Indicted on Federal Charges Involving Illegal Possession and Sale of 
Firearms, DOJ/OPA (Sept. 29, 2021), available at https://www.justice.gov/usao-dc/pr/two-district-men-indicted-federal-charges-involving-illegal-possession-and-sale-firearms; Bronx Man 
Who Possessed Five ``Ghost Guns'' Charged With Possessing A Firearm 
And Ammunition, DOJ/OPA (Oct. 5, 2021), available at https://www.justice.gov/usao-sdny/pr/bronx-man-who-possessed-five-ghost-guns-charged-possessing-firearm-and-ammunition; Fresno Felon 
Indicted for Possession of Ammunition, DOJ/OPA (Oct. 7, 2021), 
available at https://www.justice.gov/usao-edca/pr/fresno-felon-indicted-possession-ammunition; District Man Sentenced to 10\1/2\ 
Years in Prison for Armed Robbery and Earlier Shooting, DOJ/OPA 
(Oct. 13, 2021), available at https://www.justice.gov/usao-dc/pr/district-man-sentenced-10-years-prison-armed-robbery-and-earlier-shooting; Brooklyn Felon Sentenced to 48 Months' Imprisonment for 
Possessing Arsenal of Weapons Including ``Ghost Guns'', DOJ/OPA 
(Oct. 12, 2021), available at https://www.justice.gov/usao-edny/pr/brooklyn-felon-sentenced-48-months-imprisonment-possessing-arsenal-weapons-including; Syracuse Man Pleads Guilty to Unlawfully 
Possessing and Selling Firearms and Ammunition, DOJ/OPA (Oct. 15, 
2021), available at https://www.justice.gov/usao-ndny/pr/syracuse-man-pleads-guilty-unlawfully-possessing-and-selling-firearms-and-ammunition; Two Men Indicted for Firearms Trafficking, DOJ/OPA (Oct. 
28, 2021), available at https://www.justice.gov/usao-edca/pr/two-men-indicted-firearms-trafficking; Tattoo Shop Owner Sentenced to 
Prison for Possessing Unlicensed Firearms at his Business, DOJ/OPA 
(Oct. 28, 2021), available at https://www.justice.gov/usao-wdpa/pr/tattoo-shop-owner-sentenced-prison-possessing-unlicensed-firearms-his-business; Mexican National Charged with Possessing Firearms, 
Methamphetamine in Checked Luggage at MSP Airport, DOJ/OPA (Nov. 2, 
2021), available at https://www.justice.gov/usao-mn/pr/mexican-national-charged-possessing-firearms-methamphetamine-checked-luggage-msp-airport; Lawrence Man Arrested on Firearms and Narcotics 
Charges, DOJ/OPA (Nov. 4, 2021), available at https://www.justice.gov/usao-ma/pr/lawrence-man-arrested-firearms-and-narcotics-charges; Colchester Man Sentenced to 34 Months in Federal 
Prison for Illegally Possessing Machinegun, DOJ/OPA (Nov. 12, 2021), 
available at https://www.justice.gov/usao-ct/pr/colchester-man-sentenced-34-months-federal-prison-illegally-possessing-machinegun; 
Ocean County Man Charged with Illegally Possessing Loaded Semi-
Automatic Rifle, DOJ/OPA (Nov. 16, 2021), available at https://www.justice.gov/usao-nj/pr/ocean-county-man-charged-illegally-possessing-loaded-semi-automatic-rifle; New Haven Gang Member 
Charged with Federal Firearm and Narcotics Offenses, DOJ/OPA (Nov. 
17, 2021), available at https://www.justice.gov/usao-ct/pr/new-haven-gang-member-charged-federal-firearm-and-narcotics-offenses; 
Edmund H. Mahony, Gang task force accuses two East Hartford men of 
using 3D printers to manufacture and sell hard-to-track `ghost 
guns,' Hartford Courant (Jan. 7, 2022), available at https://www.courant.com/news/connecticut/hc-news-ghost-gun-arrests-20220107-20220107-hqa4ggdygvfxdemh7kihaocqxy-story.html (last visited Mar. 
22, 2022).

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[[Page 24658]]

    The problem of untraceable firearms being acquired and used by 
violent criminals and terrorists is international in scope.\21\ The 
NPRM highlighted Congress's concern, based on intelligence reports from 
the Department of Homeland Security (``DHS''), the Federal Bureau of 
Investigation (``FBI''), and the National Counterterrorism Center 
(``NCTC''), that untraceable firearms pose a challenge to law 
enforcement's ability to investigate crimes and that ``wide 
availability of ghost guns and the emergence of functional 3D-printed 
guns are a homeland security threat.'' \22\ Numerous criminal 
investigations and studies have also demonstrated these concerns,\23\ 
while several States and municipalities have banned or severely 
restricted unserialized or 3D-printed firearms.\24\
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    \21\ Firearms using 3D-printed components seized in Sweden, 
Armament Research Services (May 19, 2017), available at https://armamentresearch.com/3d-printed-firearms-seized-in-sweden (last 
visited Mar. 22, 2022); Lizzie Dearden, Use of 3D printed guns in 
German synagogue shooting must act as warning to security services, 
experts say, independent.co.uk (Oct. 11, 2019), available at https://www.independent.co.uk/news/world/europe/3d-gun-print-germany-synagogue-shooting-stephan-balliet-neo-nazi-a9152746.html (last 
visited Mar. 22, 2022); G. Hays, Multiple 3D-printed Firearms Seized 
in Sydney, Australia, Armament Research Services (Aug. 11, 2020), 
available at https://armamentresearch.com/multiple-3d-printed-firearms-seized-in-sydney-australia (last visited Mar. 22, 2022); 
Glock ghost guns up for grabs on the dark web, Australian National 
University (Mar. 23, 2021), available at https://www.anu.edu.au/news/all-news/glock-ghost-guns-up-for-grabs-on-the-dark-web (last 
visited Mar. 22, 2022); Spain dismantles workshop making 3D-printed 
weapons, BBC (Apr. 19, 2021), available at https://www.bbc.com/news/world-europe-56798743 (last visited Mar. 22, 2022); Liam Reilly & 
Alaa Elassar, A Rhode Island man was arrested for allegedly selling 
`ghost guns' and trafficking firearms to the Dominican Republic, CNN 
(Jan. 9, 2022), available at https://www.cnn.com/2022/01/09/us/rhode-island-ghost-guns-dominican-republic/index.html (last visited 
Mar. 22, 2022).
    \22\ H.R. Rep. No. 116-88, at 2 (2019). The House Report cited a 
January 11, 2019 Joint Intelligence Bulletin issued by DHS, FBI, and 
NCTC concluding that ``these rapidly evolving technologies pose an 
ongoing, metastasizing challenge to law enforcement in 
understanding, tracking, and tracing ghost guns,'' and an April 22, 
2019 DHS intelligence assessment that ``repeated the warning that 
ghost guns pose an urgent and evolving threat to the homeland, 
particularly in the hands of ideologically motivated lone wolf 
actors.'' Id.
    \23\ Paul Ingram, CBP: 3-D-printed full-auto rifle seized at 
Lukeville crossing, tucsonsentinel.com (Feb. 8, 2016), available at 
http://www.tucsonsentinel.com/local/report/020816_3d_printed_gun/cbp-3-d-printed-full-auto-rifle-seized-lukeville-crossing (last 
visited Mar. 22, 2022); Dark Web Gun Trafficker from Nevada County 
Pleads Guilty to Unlawful Dealing in Firearms, DOJ/OPA (June 22, 
2018), available at https://www.justice.gov/usao-edca/pr/dark-web-gun-trafficker-nevada-county-pleads-guilty-unlawful-dealing-firearms; Mahita Gajanan, The TSA Has Found 3D-Printed Guns at 
Airport Checkpoints 4 Times Since 2016, Time (Aug. 2, 2018), 
available at https://time.com/5356179/3d-printed-guns-tsa (last 
visited Mar. 22, 2022); Grass Valley Man Sentenced to 5 Years in 
Prison for Unlawfully Manufacturing Ghost Guns and Selling Them on 
Dark Web, DOJ/OPA (Sept. 21, 2018), available at https://www.justice.gov/usao-edca/pr/grass-valley-man-sentenced-5-years-prison-unlawfully-manufacturing-ghost-guns-and; Indiana Residents 
Indicted on Terrorism and Firearms Charges, DOJ/OPA (July 11, 2019), 
available at https://www.justice.gov/opa/pr/indiana-residents-indicted-terrorism-and-firearms-charges; Fishers residents indicted 
on terrorism and firearms charges, DOJ/OPA (July 12, 2019), 
available at https://www.justice.gov/usao-sdin/pr/fishers-residents-indicted-terrorism-and-firearms-charges; Brandi Vincent, TSA 
Confiscated 3D-Printed Guns at Raleigh-Durham International Airport, 
nextgov.com (Mar. 4, 2020), available at https://www.nextgov.com/emerging-tech/2020/03/tsa-confiscated-3d-printed-guns-raleigh-durham-international-airport/163533 (last visited Mar. 22, 2022); 
Man Sentenced for Attempting to Board International Flight with a 
Loaded Firearm, DOJ/OPA (Mar. 12, 2021), available at https://www.justice.gov/usao-sdca/pr/man-sentenced-attempting-board-international-flight-loaded-firearm; Lizzie Dearden, Police issue 
warning over terrorist use of 3D-printed guns as UK neo-Nazi jailed, 
MSN News (June 14, 2021), available at https://www.msn.com/en-gb/news/uknews/police-issue-warning-over-terrorist-use-of-3d-printed-guns-as-uk-neo-nazi-jailed/ar-AAL2G36 (last visited Mar. 22. 2022); 
Davide Sher, Oceanian media report seizures of 3D printed guns, 
submachine guns, 3D Printing Media Network (June 22, 2021), https://www.3dprintingmedia.network/oceanian-media-report-seizures-of-3d-printed-guns-submachine-guns (last visited Mar. 22, 2022); Dr. 
Yannick Veilleux-Lepage, CTRL, HATE, PRINT: Terrorists and the 
appeal of 3D-printed weapons, International Centre for Counter-
Terrorism (July 13, 2021), available at https://icct.nl/publication/ctrl-hate-print-terrorists-and-the-appeal-of-3d-printed-weapons 
(last visited Mar. 22, 2022); Chuck Goudie et al., Al Qaeda launches 
1st public campaign in 4 years to encourage lone wolf terrorist 
attacks, ABC7 Chicago (July 29, 2021), available at https://abc7chicago.com/al-qaeda-terrorism-terrorist-attack-inspire-magazine/10918191 (last visited Mar. 22, 2022); Huder Abbasi, What's 
behind far-right trend of using 3D tech to make guns?, Aljazeera.com 
(July 31, 2021), available at https://www.aljazeera.com/news/2021/7/31/what-behind-far-right-trend-using-3d-tech-make-guns (last visited 
Mar. 22, 2022); Fergus Hunter, Alleged right-wing extremist charged 
over blueprint to 3D-print a gun, The Sydney Morning Herald (Sept. 
13, 2021), available at https://www.smh.com.au/national/nsw/alleged-right-wing-extremist-arrested-over-blueprint-to-3d-print-a-gun-20210913-p58r80.html (last visited Mar. 22, 2022); Mexican National 
Charged with Possessing Firearms, Methamphetamine in Checked Luggage 
at MSP Airport, DOJ/OPA (Nov. 2, 2021), available at https://www.justice.gov/usao-mn/pr/mexican-national-charged-possessing-firearms-methamphetamine-checked-luggage-msp-airport.
    \24\ See Cal. Penal Code. sec. 29180 (prohibiting ownership of 
firearms that do not bear a serial number or other mark of 
identification provided by the State); Conn. Gen. Stat. sec. 29-
36a(a) (prohibiting manufacture of firearms without permanently 
affixing serial numbers issued by the State); Del. Code Ann. tit. 11 
secs. 1459A, 1462 (prohibiting possession of an unfinished frame or 
receiver with no serial number and untraceable firearms); DC Code 
sec. 7-2504.08(a) (prohibiting licensees from selling firearms 
without serial numbers); Haw. Rev. Stat. sec. 134-10.2 (prohibiting 
unlicensed persons from producing, purchasing, or possessing 3D-
printed or parts kit firearms without a serial number); Mass. Gen. 
Laws Ch. 269 sec. 11E (prohibiting manufacture or delivery of 
unserialized firearms to licensed dealer); N.J. Stat. Ann. sec. 
2C:39-3(n) (prohibiting possession of firearms manufactured or 
assembled without serial number); N.Y. Penal Law secs. 265.50, 
265.55 (prohibiting manufacture/possession of undetectable 
firearms); R.I. Gen. Laws sec. 11-47-8(e) (prohibiting possession of 
``a ghost gun or an undetectable firearm or any firearm produced by 
a 3D printing process''); Va. Code. Ann. sec. 18.2-308.5 
(prohibiting possession of undetectable firearms); Wash. Rev. Code 
sec. 9.41.190 (prohibiting the manufacture with intent to sell of 
undetectable and untraceable firearms); see also Bill to ban ghost 
guns passes in Maryland House, heads to Gov. Hogan's desk, wjla.com 
(Mar. 29, 2022), available at https://wjla.com/news/local/ghost-guns-ban-bill-passes-maryland-house-maryland-governor-larry-hogan-signs-gun-control (last visited Apr. 3, 2022); Zenon Evans, 
Philadelphia Becomes First City To Ban 3D-Printed Gun Manufacturing, 
Reason.com (Nov. 22, 2013), available at https://reason.com/2013/11/22/philadelphia-becomes-first-city-to-ban-3 (last visited Mar. 22, 
2022); Council unanimously approves Ghost Guns Bill, restricting the 
sale [or] transfer of ghost guns to minors, Montgomerycountymd.gov 
(Apr. 6, 2021), available at https://www2.montgomerycountymd.gov/mcgportalapps/Press_Detail.aspx?Item_ID=34040&Dept=1 (last visited 
Mar. 22, 2022); Chris Gros, Mayor Gloria signs ban on ghost guns in 
San Diego, CBS8 (Sept. 23, 2021), available at https://www.cbs8.com/article/news/local/mayor-gloria-signs-ban-on-ghost-guns-in-san-diego/509-ddd5f49d-29dc-42a6-8f2c-41f17381718f (last visited Mar. 
22, 2022); Julia Wick, L.A. City Council votes to ban `ghost guns', 
Police1.com (Dec. 1, 2021), available at https://www.police1.com/gun-legislation-law-enforcement/articles/la-city-council-votes-to-ban-ghost-guns-8Rre0xK860ryrYud (last visited Mar. 22, 2022); Hannah 
Metzger, Denver outlaws owning, manufacturing `ghost guns' in city, 
denvergazette.com (Jan. 3, 2022), available at https://denvergazette.com/news/government/denver-outlaws-owning-manufacturing-ghost-guns-in-city/article_88799392-6d04-11ec-9da0-134e7e7be5f2.html (last visited Mar. 22, 2022); Jakob Rodgers, 
Oakland joins growing list of California cities to ban ghost guns, 
mercurynews.com (Jan. 18, 2022), available at https://www.mercurynews.com/2022/01/18/oakland-joins-growing-list-of-california-cities-to-ban-ghost-guns (last visited Mar. 22, 2022).

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[[Page 24659]]

    Courts have recognized that the information licensees are required 
to record and maintain under the GCA ``enable[s] federal authorities 
both to enforce the law's verification measures and to trace firearms 
used in crimes.'' Abramski v. United States, 573 U.S. 169, 173 (2014) 
(citing H.R. Rep. No. 1577, 90th Cong., 2d Sess., 14 (1968)). At least 
one court has also concluded that ATF has a statutory duty pursuant to 
the GCA to trace firearms to keep them out of the hands of criminals 
and other prohibited persons. Blaustein & Reich, Inc. v. Buckles, 220 
F. Supp. 2d 535, 537 (E.D. Va. 2002). This duty includes assisting 
State and local law enforcement in their efforts to control the traffic 
of firearms within their borders.\25\ Indeed, as of January 2022, there 
are approximately 8,674 law enforcement agencies, including 49 agencies 
from 46 foreign countries, that use eTrace, a web-based application 
administered by ATF that allows authorized law enforcement agencies to 
submit and conduct comprehensive traces of recovered crime guns and 
develop long-term strategies on how best to reduce firearms-related 
crime, firearms trafficking, and violence in their communities.\26\
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    \25\ See Public Law 90-351, sec. 901(a), 82 Stat. 212, 225-26 
(1968); 18 U.S.C. 922(b)(2) (prohibiting licensees from selling or 
delivering any firearm to any person in a State where the purchase 
or possession by such person of such firearm would be in violation 
of any State law or published ordinance applicable at the place of 
sale, delivery, or other disposition); 18 U.S.C. 922(t)(2), (4) 
(NICS background check denied if receipt of firearm by transferee 
would violate State law); 18 U.S.C. 923(d)(1)(F) (requiring license 
applicants to certify compliance with the requirements of State and 
local law applicable to the conduct of business).
    \26\ Fact Sheet, eTrace: Internet-Based Firearms Tracing and 
Analysis, ATF (Sept. 2021), available at https://www.atf.gov/resource-center/fact-sheet/fact-sheet-etrace-internet-based-firearms-tracing-and-analysis.
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    As discussed in the NPRM, tracing is an integral tool for Federal, 
State, local, and international law enforcement agencies to utilize in 
their criminal investigations, and the proliferation of untraceable 
firearms severely undermines this process. 86 FR at 27724-25. The NPRM 
described the overall process that ATF engages in when tracing firearms 
submitted by law enforcement. Id. at 27724. The Department stressed how 
ATF relies on the recordkeeping required to be maintained by licensees 
in order to locate the first unlicensed person who acquired the 
recovered firearm from a licensed dealer.\27\ This information can help 
find the perpetrator or provide valuable leads that help to solve the 
crime. Thus, for a successful trace to be conducted, an accurate 
firearm description is necessary and required to be recorded by a 
person licensed to engage in the business of manufacturing, importing, 
or dealing in firearms, or by a licensed collector of curio or relic 
firearms, regardless of whether it is a business or personal firearm of 
the licensee.\28\
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    \27\ Licensees must respond to ATF trace requests within 24 
hours. 18 U.S.C. 923(g)(7); see also J&G Sales Ltd. v. Truscott, 473 
F.3d 1043, 1045-46 (9th Cir. 2007) (describing the tracing process).
    \28\ See 18 U.S.C. 923(c); 27 CFR 478.125a(a)(4) (licensed 
manufacturers, importers, and dealers must record in a bound volume 
a complete description of firearms disposed of from their personal 
collections); 18 U.S.C. 923(g)(1)(A), (D); 27 CFR 478.125(e), (f) 
(licensed dealer and collector disposition records must contain a 
complete description of the firearm); 132 Cong. Rec. 15229 (1986) 
(Statement of Rep. Hughes) (``In order for the law enforcement 
Firearm Tracing Program to operate, some minimal level of 
recordkeeping is required [for sales from dealers' personal 
collections]. Otherwise, we will not have tracing capability. This 
provision simply requires that a bound volume be maintained by the 
dealer of the sales of firearms which would include a complete 
description of the firearm, including its manufacturer, model 
number, and its serial number and the verified name, address, and 
date of birth of the purchaser. This is only a minimal inconvenience 
for the dealer, yet obtaining and recording this information is 
critical to avoid serious damage to the Firearm Tracing Program.'').
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    Because PMFs lack serial numbers and other markings from a licensed 
manufacturer, ATF has found it extremely difficult to successfully 
complete traces of PMFs. Out of the approximately 45,240 submitted 
traces of suspected PMFs mentioned above, ATF could only successfully 
complete approximately 445 of those attempted traces to an individual 
unlicensed purchaser.\29\ Successful traces of PMFs have been completed 
in these rare instances primarily because licensees who acquired PMFs 
sometimes recorded a serial number that had been voluntarily engraved 
by the manufacturer on a commercially produced handgun slide, barrel, 
or another firearm part, which are not required by the GCA to be 
marked.
---------------------------------------------------------------------------

    \29\ Source: ATF Office of Strategic Intelligence and 
Information. These numbers (as of January 21, 2022) include traces 
for both U.S. and international law enforcement agencies.
---------------------------------------------------------------------------

    In the NPRM, the Department noted that, with the rapid emergence of 
PMFs in recent years, licensees have sought clarity from ATF on how 
PMFs may be accepted and recorded. 86 FR at 27724-25. Licensees engaged 
in the business of dealing in firearms are subject to various recording 
and reporting requirements, including completion of a Firearms 
Acquisition and Disposition Record (``A&D Record'') to record their 
firearms inventory,\30\ a Firearms Transaction Record, ATF Form 4473 
(``Form 4473''), for disposition of a firearm to an unlicensed 
person,\31\ a Federal Firearms Licensee Theft/Loss Report, ATF Form 
3310.11, upon discovery of the theft or loss of firearms,\32\ and a 
Report of Multiple Sale or Other Disposition of Pistols and Revolvers, 
ATF Form 3310.4, to document sales or other dispositions of multiple 
pistols or revolvers within five consecutive business days to the same 
person.\33\ These forms require licensees to record the manufacturer 
and importer (if any), model (if designated), serial number, type, and 
caliber or gauge of the firearm.
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    \30\ 27 CFR 478.125(e).
    \31\ 18 U.S.C. 923(g)(1)(A); 27 CFR 478.124.
    \32\ 18 U.S.C. 923(g)(6); 27 CFR 478.39a(b).
    \33\ 18 U.S.C. 923(g)(3)(A); 27 CFR 478.126a. Pursuant to 18 
U.S.C. 923(g)(5)(A), licensed dealers along the Southwest U.S. 
border are also required by demand letter to report to ATF multiple 
sales of certain rifles during five consecutive business days to the 
same person on ATF Form 3310.12, including the rifle's serial 
number, manufacturer, importer, model, and caliber. Also under that 
statute, licensed dealers with 25 or more trace requests with a 
``time-to-crime'' of three years or less must report to ATF the 
acquisition date, model, caliber or gauge, and the serial number of 
a secondhand firearm transferred by the dealer.
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    As applied to PMFs, licensees acquiring them might only record a 
``type'' of firearm (e.g., pistol, revolver, rifle, or shotgun) in 
their A&D records and on Forms 4473. With such limited information, it 
will become increasingly difficult, if not impossible, for licensees 
and ATF (during inspections) to match accurately and reliably the PMFs 
in the firearms inventory with those recorded in required A&D records, 
or to determine whether the PMFs recorded as disposed on Forms 4473 are 
those recorded as disposed in the A&D records.\34\ Likewise, licensees 
and ATF

[[Page 24660]]

will have difficulty accurately determining which PMFs were stolen or 
lost from inventory. It will also be difficult for police to locate 
stolen PMFs in the business inventories of pawnbrokers, for 
example,\35\ or to return any recovered stolen or lost PMFs to their 
rightful owners.
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    \34\ In United States v. Biswell, 406 U.S. 311, 315-16 (1972), 
the Supreme Court explained that ``close scrutiny of [firearms] 
traffic is undeniably of central importance to federal efforts to 
prevent violent crime and to assist the States in regulating the 
firearms traffic within their borders. Large interests are at stake, 
and inspection is a crucial part of the regulatory scheme, since it 
assures that weapons are distributed through regular channels and in 
a traceable manner and makes possible the prevention of sales to 
undesirable customers and the detection of the origin of particular 
firearms'' (citation omitted).
    \35\ Most states require pawnbrokers to record or report any 
serial number and other identifying markings on pawned merchandise 
so that police can determine their origin. See Ala. Code sec. 5-19A-
3(1); Alaska Stat. sec. 08.76.180(a)(4); Ariz. Rev. Stat. sec. 44-
1625(C)(5); Colo. Rev. Stat. sec. 29-11.9-103(1); Conn. Gen. Stat. 
sec. 21-41(c); Del. Code Ann. tit. 24, sec. 2302(a)(1)(b); D.C. Code 
sec. 47-2884.11(d); Fla. Stat. sec. 538.04(1)(b)(3), (9); Ga. Code 
sec. 44-12-132(4); Haw. Rev. Stat. sec. 445-134.11(c)(10); 205 Ill. 
Comp. Stat. 510/5(a); Ind. Code sec. 28-7-5-19(a)(4); Ky. Rev. Stat. 
Ann. Sec. 226.040(1)(d)(7); La. Stat. Ann. sec. 37:1782(16)(a); 
Mass. Gen. Laws ch. 140 sec. 79; Mich. Comp. Laws sec. 
446.205(5)(1), (4); Minn. Stat. sec. 325J.04(Sub.1)(1); Miss. Code 
Ann. sec. 75-67-305(1)(a)(iii), (ix); Mo. Rev. Stat. sec. 
367.040(4)(6)(b); Neb. Rev. Stat. sec. 69-204(3); N.M. Stat. Ann. 
sec. 56-12-9(A)(3); N.C. Gen. Stat. sec. 66-391(b)(1); Ohio Rev. 
Code Ann. sec. 4727.07; Okla. Stat. tit. 59 sec. 1509(D)(h); S.C. 
Code Ann. sec. 40-39-80(B)(1)(l)(iii), (ix); Tenn. Code Ann. sec. 
45-6-209(b)(1)(C), (H); Tex. Fin. Code Ann. sec. 371.157(4); Utah 
Code Ann. sec. 13-32a-104(1)(h)(i)(A); Va. Code Ann. sec. 54.1-
4009(A)(1); Wash. Rev. Code sec. 19.60.020(1)(e); W. Va. Code sec. 
47-26-2(b)(1); Wis. Stat. sec. 134.71(8)(c)(2).
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    Assuming a PMF can be successfully traced to a Federal firearms 
licensee (``FFL'') or that a correct Form 4473 can be located, the NPRM 
explained that the ATF Form 4473 is the primary evidence used to 
prosecute straw purchasers who buy firearms from FFLs typically on 
behalf of prohibited persons, such as felons or illegal firearms 
traffickers, and other persons who could use the firearms to commit 
violent crimes.\36\ The form is typically the key evidence that the 
straw purchaser who bought the firearm (and who can pass a background 
check) made a false statement to the FFL concerning the identity of the 
actual purchaser when acquiring that firearm, in violation of 18 U.S.C. 
922(a)(6) and 924(a)(1)(A), or State law.\37\ But as unmarked and 
difficult-to-trace PMFs are transacted throughout the commercial 
marketplace, law enforcement will have difficulties prosecuting straw 
purchasers for making false statements because it will be harder to 
prove that the firearms acquired under false pretenses on a Form 4473 
were the ones found in the hands of the true purchaser.\38\ Likewise, 
the absence of identifying firearm information on multiple sales forms 
and theft/loss reports makes it more difficult for ATF to identify 
firearms traffickers and thieves.\39\
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    \36\ See United States v. Marzzarella, 614 F.3d 85, 100 (3d Cir. 
2010) (``The direct tracing of the chain of custody of firearms 
involved in crimes is one useful means by which serial numbers 
assist law enforcement. But serial number tracing also provides 
agencies with vital criminology statistics--including a detailed 
picture of the geographical source areas for firearms trafficking 
and ``time-to-crime'' statistics which measure the time between a 
firearm's initial retail sale and its recovery in a crime--as well 
as allowing for the identification of individual dealers involved in 
the trafficking of firearms and the matching of ballistics data with 
recovered firearms'' (footnotes omitted).); Following the Gun: 
Enforcing Federal Laws Against Firearms Traffickers, ATF at 1, 26 
(2000) (serial number obliteration is a clear indicator of firearms 
trafficking to, among other criminals, armed narcotics traffickers).
    \37\ See, e.g., Abramski v. United States, 573 U.S. 169, 192 
(2014); Marshall v. Virginia, 822 SE2d 389, 392-93 (Va. Ct. App. 
2019); Shirley v. Glass, 297 Kan. 888 (2013); Pennsylvania v. 
Baxter, 956 A.2d 465, 472 (Pa. Super. Ct. 2008).
    \38\ See, e.g., United States v. Powell, 467 F. Supp. 3d 360, 
368, 374 (E.D. Va. 2020) (indictment charging false statements on 
ATF Form 4473 in connection with the purchase of specific handguns 
listed by date of purchase, make, caliber, model, serial number, and 
name of FFL); United States v. McCurdy, 634 F. Supp. 2d 118, 121-22, 
126 (D. Me. 2009) (denial of a motion for a new trial discussing 
whether the firearm sold as documented on the ATF Form 4473 and the 
firearm introduced at trial were the same).
    \39\ The lack of firearm description information in theft/loss 
reports makes it difficult for ATF to match recovered firearms with 
those reported as lost or stolen, thereby hindering ATF's efforts to 
enforce the numerous provisions of the GCA that prohibit thefts. See 
18 U.S.C. 922(i) (transporting or shipping stolen firearms in 
interstate or foreign commerce); 18 U.S.C. 922(j) (receiving, 
possessing, concealing, storing, bartering, selling, disposing, or 
pledging or accepting as security for a loan any stolen firearm 
which has moved in interstate or foreign commerce); 18 U.S.C. 922(u) 
(stealing a firearm that has been shipped or transported in 
interstate or foreign commerce from the person or premises of an 
FFL); 18 U.S.C. 924(l) (stealing a firearm which is moving in or has 
moved in interstate commerce); 18 U.S.C. 924(m) (stealing a firearm 
from a licensee).
---------------------------------------------------------------------------

C. Advanced Notice of Proposed Rulemaking on Identification Markings 
Placed on Firearm Silencers and Firearm Mufflers

    The NPRM noted that on May 4, 2016, the Department published an 
advance notice of proposed rulemaking (``ANPRM'') in the Federal 
Register. 86 FR 27728 n.50 (citing 81 FR 26764). The ANPRM was issued 
in response to a petition filed on behalf of the National Firearms Act 
Trade and Collectors Association (``NFATCA''), a trade group 
representing the firearms and import community. The petitioner 
requested that the relevant regulations be amended to require that a 
silencer be marked on the outer tube as opposed to other locations, 
such as an end cap that might be damaged when a projectile passes 
through it, unless a variance is granted by the Director on a case-by-
case basis for good cause. ATF found that the petitioner raised valid 
concerns.
    Under the GCA, licensed manufacturers and importers must identify 
the frame or receiver of each firearm, including a firearm muffler or 
silencer, with a serial number in accordance with regulations. 18 
U.S.C. 921(a)(3)(C), 923(i). The NFA requires firearm manufacturers, 
importers, and makers to identify each firearm, including a firearm 
muffler or silencer, with a serial number and such other identification 
as may be prescribed by regulations. 26 U.S.C. 5842(a), 5845(a)(7). 
Because the NFA defines each individual part of a firearm muffler or 
silencer as a ``firearm'' \40\ that must be registered in the NFRTR, 
the regulations currently assume that every part defined as a silencer 
must be marked in order to be registered, and expressly require that 
each part be marked whenever sold, shipped, or otherwise disposed of 
even though it may have been installed by a qualified licensee within a 
complete muffler or silencer device.\41\
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    \40\ A firearm ``muffler or silencer'' is defined to include 
``any combination of parts'' designed and intended for the use in 
assembling or fabricating a firearm silencer or muffler and ``any 
part intended only for use in such assembly or fabrication.'' 18 
U.S.C. 921(a)(24); 26 U.S.C. 5845(a)(7); 27 CFR 478.11, 479.11. This 
rule defines the term ``complete muffler or silencer device'' not to 
exempt individual silencer parts from the definition of firearm 
``muffler or silencer'' subject to the requirements of the NFA, but 
to advise industry members when those individual silencer parts must 
be marked and registered in the NFRTR when they are used in 
assembling, fabricating, or repairing a muffler or silencer device.
    \41\ See 27 CFR 479.101(b), 478.92(a)(4)(iii), 479.102(f)(1).
---------------------------------------------------------------------------

    The ANPRM explained that, along with industry members, ATF 
considers the term ``outer tube'' to mean the largest external part of 
a silencer and is that portion of a silencer that encapsulates all 
components of the silencing unit, and which contains and controls the 
expansion of the escaping gases. 81 FR at 26765. ATF explained that 
placing all required markings on the outer tube of a completed firearm 
silencer or firearm muffler is the accepted industry standard. In 
addition, ATF discussed that requiring identification markings to be 
placed on a single part provides consistency of markings throughout the 
industry and eliminates the need to re-mark a device in the event an 
end cap bearing the markings is damaged and requires replacement. ATF 
believed that a more specific marking requirement for firearm 
silencers, such as the outer tube, would lead to greater uniformity, 
improve public safety, and decrease firearms crimes, including firearms 
trafficking. See id.
    The ANPRM was used to solicit comments to determine if an amendment 
to the regulations that would require placement of

[[Page 24661]]

identification markings on the outer tube of firearm silencers and 
mufflers was warranted. In response to the ANPRM, ATF received 48 
comments. A few commenters supported issuance of a proposed rule 
because they believed it would not violate any constitutional rights 
under the Second Amendment, would enhance public safety for the reasons 
ATF stated, and would reduce confusion within the industry without 
being a financial burden because it is already a standard practice with 
many manufacturers. The majority of commenters expressed opposition and 
did not want ATF to proceed with any further rulemaking. Specific 
reasons for their objection to a proposed rule included a belief that: 
(1) ATF lacks legal authority to specify where markings on silencers 
must be located and that such a rule would violate the Second 
Amendment; (2) the initial NFATCA petition is outdated; (3) there is no 
data to support that a new rule would enhance public safety or reduce 
firearms trafficking; (4) a new regulation is unnecessary as the 
industry is already complying; (5) it is not feasible to comply with 
marking on the outer tube of the silencer with specific designs; (6) 
the proposed idea hinders technological advances and future designs; 
(7) it would create confusion and definitional problems because the 
definition of outer tube is outdated; and (8) the industry and public 
would incur financial burdens.
    Other commenters offered suggestions about outer tube replacement 
options especially because silencer tubes wear out over time. They 
suggested that a rule would be reasonable if ATF authorizes 
manufacturers to repair or replace damaged silencer tubes and engrave 
the new tube with the original serial number. Commenters also suggested 
alternative locations for silencer markings such as on end caps. They 
believed that markings should be placed on the major portion of the 
silencer, which could be the end cap or any section of the tube. They 
stressed that the outer tube is thin and there is a greater risk of 
burning through the metal when engraving and that end caps have greater 
thickness to work with when engraving.
    Based on further review and the comments received in response to 
the ANPRM, ATF incorporated a proposed definition of ``frame or 
receiver'' as it applies to firearm mufflers and silencers in the NPRM 
to clarify when and how silencer parts are to be marked and registered. 
86 FR 27720.

III. Notice of Proposed Rulemaking

    On May 21, 2021, the Department published in the Federal Register 
an NPRM entitled ``Definition of `Frame or Receiver' and Identification 
of Firearms,'' 86 FR 27720, proposing changes to various regulations in 
27 CFR parts 447, 478, and 479. Overall, the NPRM proposed amending 
ATF's regulations to clarify the definition of ``firearm'' and to 
provide a more comprehensive definition of ``frame or receiver'' so 
that these terms more accurately reflect how most modern-day firearms 
are produced and function, and so that the courts, the firearms 
industry, and the public at large would no longer misinterpret the term 
to mean that most firearms in circulation have no parts identifiable as 
a frame or receiver. The NPRM also proposed new terms and definitions 
to account for technological developments and modern terminology in the 
firearms industry, as well as proposed amendments to the marking and 
recordkeeping requirements that would be necessary to implement these 
definitions.

A. Definition of ``Firearm''

    In the NPRM, the Department proposed adding a sentence at the end 
of the definition of ``firearm'' in 27 CFR 478.11 to reflect existing 
case law, providing that ``[t]he term shall include a weapon parts kit 
that is designed to or may readily be assembled, completed, converted, 
or restored to expel a projectile by the action of an explosive.'' 
However, the proposed amendment was not intended to affect the 
classification of a weapon, including a weapon parts kit, in which the 
frame or receiver (as defined in the proposed rule) of such weapon is 
properly destroyed. See 86 FR at 27726, 27729-30. Therefore, another 
sentence was proposed to be added at the end of the definition of 
``firearm'' to provide that ``[t]he term shall not include a weapon, 
including a weapon parts kit, in which each part defined as a frame or 
receiver of such weapon is destroyed.'' Id. at 27726.
    The Department explained in the NPRM that ``firearm'' as defined 
under the GCA, 18 U.S.C. 921(a)(3) and 27 CFR 478.11, includes 
inoperable weapons even though they will not expel a projectile by the 
action of an explosive at the time of sale or distribution if they are 
``designed to'' \42\ or ``may readily be converted'' \43\ to expel a 
projectile by the

[[Page 24662]]

action of an explosive. Weapon parts kits, or aggregations of weapon 
parts, some of which contain all of the components necessary to 
complete a functional weapon within a short period of time, have been 
increasingly sold to individuals either directly from manufacturers of 
the kits or retailers, without background checks or recordkeeping. 86 
FR at 27726. Some of these firearm kits include jigs, templates, and 
tools that allow the purchaser to complete the weapon fairly or 
reasonably efficiently, quickly, and easily to a functional state. Such 
weapon parts kits or aggregations of weapon parts that are designed to 
or may readily be converted to expel a projectile by the action of an 
explosive are also ``firearms'' under 18 U.S.C. 921(a)(3)(A).\44\ This 
proposed addition makes explicit that manufacturers and sellers of such 
kits or aggregations of weapon parts are subject to the same regulatory 
requirements applicable to the manufacture or sale of fully completed 
and assembled firearms. See 86 FR at 27726.
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    \42\ Numerous courts have held that weapons designed to expel a 
projectile by the action of an explosive are ``firearms'' under 18 
U.S.C. 921(a)(3)(A) even if they cannot expel a projectile in their 
present form or configuration. See, e.g., United States v. Hardin, 
889 F.3d 945, 946-47, 949 (8th Cir. 2018) (pistol with broken 
trigger and numerous missing internal parts was a weapon designed to 
expel a projectile by the action of an explosive); United States v. 
Dotson, 712 F.3d 369, 370-71 (7th Cir. 2013) (saying, in ruling that 
a pistol with corroded, missing, and broken components was a 
``firearm,'' that ``[a]n airplane is designed to fly; a defect in 
manufacture or maintenance that prevents it from flying does not 
alter its design''); United States v. Davis, 668 F.3d 576, 577 (8th 
Cir. 2012) (holding that a pistol with no trigger was a ``firearm'' 
within the meaning of section 2K2.1(a)(3)(A)(i) of the Sentencing 
Guidelines and applying ``the same reasoning [that courts have 
applied in section 921(a)(3) cases] to Guidelines provisions that 
incorporate the Sec.  921(a)(3) definition''); United States v. 
Counce, 445 F.3d 1016, 1018 (8th Cir. 2006) (handgun with missing 
safety); United States v. Rivera, 415 F.3d 284, 285-87 (2d Cir. 
2005) (pistol with a broken firing pin and flattened firing-pin 
channel); United States v. Morales, 280 F. Supp. 2d 262, 272-73 
(S.D.N.Y. 2003) (partially disassembled Tec-9 pistol was designed to 
expel a projectile); United States v. Adams, 137 F.3d 1298, 1300 & 
n.2 (11th Cir. 1998) (potentially inoperable shotgun); United 
States. v. Brown, 117 F.3d 353 (7th Cir. 1997) (holding that a gun 
with no firing pin was a ``firearm'' within the meaning of section 
2B3.1(b)(2)(C) of the Sentencing Guidelines, and discussing 
analogous cases interpreting section 921(a)(3)(A)); United States v. 
Reed, 114 F.3d 1053 (10th Cir. 1997) (shotgun with broken breech 
bolt); United States v. Hunter, 101 F.3d 82 (9th Cir. 1996) (holding 
that the sentence enhancement for use of a semiautomatic weapon in 
section 924(c) applied to a pistol with broken firing pin); United 
States v. Yannott, 42 F.3d 999, 1005-07 (6th Cir. 1994) (shotgun 
with broken firing pin); United States v. Ruiz, 986 F.2d 905, 910 
(5th Cir. 1993) (revolver with hammer filed down); United States v. 
York, 830 F.2d 885, 891 (8th Cir. 1987) (revolver with no firing pin 
and cylinder did not line up with barrel); United States v. Thomas, 
No. 17-194 (RDM), 2019 WL 4095569, at *4 (D.D.C. Aug. 29, 2019) (in 
ruling that a revolver missing its hammer, hammer screw, trigger, 
cylinder stop, hand, ejector rod housing, base pin, screw, nut, 
spring, loading gate detent and spring and miscellaneous screws was 
a ``firearm,'' the court said: ``[t]he Titanic was, after all, 
`designed' to be unsinkable''). But see Dotson, 712 F.3d at 371 (a 
Beretta pistol redesigned to be a cigarette lighter); Rivera, 415 
F.3d at 286-87 (``[A] gun with a barrel filled with lead, maybe for 
use as a theatrical prop, might perhaps no longer be deemed 
`designed to' or `readily be converted' to fire a bullet.''); United 
States v. Wada, 323 F. Supp. 2d 1079 (D. Or. 2004) (firearms 
redesigned as ornaments that ``would take a great deal of time, 
expertise, equipment, and materials to attempt to reactivate'' were 
no longer designed to expel a projectile by the action of an 
explosive, and could not readily be converted to do so).
    \43\ See, e.g., United States v. Mullins, 446 F.3d 750, 756 (8th 
Cir. 2006) (starter gun that can be modified in less than one hour 
by a person without any specialized knowledge to fire may be 
considered ``readily convertible'' under the GCA); United States v. 
16,179 Molso Italian .22 Caliber Winlee Derringer Convertible 
Starter Guns, 443 F.2d 463 (2d Cir. 1971) (starter guns converted in 
no more than 12 minutes to fire live ammunition were readily 
convertible under the GCA); United States v. Morales, 280 F. Supp. 
2d 262, 272-73 (S.D.N.Y. 2003) (partially disassembled Tec-9 pistol 
that could be assembled within a short period of time could readily 
be converted to expel a projectile). Cf. United States v. Dodson, 
519 F. App'x 344, 352-53 (6th Cir. 2013) (gun that was restored with 
90 minutes of work, using widely available parts and equipment and 
common welding techniques, fit comfortably within the readily 
restorable standard of 26 U.S.C. 5845(b)); United States v. TRW 
Rifle 7.62x51mm Caliber, One Model 14 Serial 593006, 447 F.3d 686, 
692 (9th Cir. 2006) (a two-hour restoration process using ordinary 
tools, including a stick weld, is within the ordinary meaning of 
``readily restored''); United States v. One TRW, Model M14, 7.62 
Caliber Rifle, 441 F.3d 416, 422-24 (6th Cir. 2006) (``[T]he 
Defendant weapon here had all of the necessary parts for restoration 
and would take no more than six hours to restore.''); United States 
v. Woods, 560 F.2d 660, 664 (5th Cir. 1977) (holding that a weapon 
was a shotgun within the meaning of 26 U.S.C. 5845(d) and stating 
``[t]he fact that the weapon was in two pieces when found is 
immaterial considering that only a minimum of effort was required to 
make it operable.''); United States v. Smith, 477 F.2d 399, 400-01 
(8th Cir. 1973) (machinegun that would take around an eight-hour 
working day in a properly equipped machine shop was readily restored 
to shoot); United States v. Catanzaro, 368 F. Supp. 450, 453 (D. 
Conn. 1973) (a sawed-off shotgun was ``readily restorable to fire'' 
where it could be reassembled in one hour and the necessary missing 
parts could be obtained at a Smith & Wesson plant). But see United 
States v. Seven Miscellaneous Firearms, 503 F. Supp. 565, 574-75 
(D.D.C. 1980) (weapons could not be ``readily restored to fire'' 
when restoration required master gunsmith in a gun shop and $65,000 
worth of equipment and tools).
    \44\ See, e.g., United States v. Wick, 697 F. App'x 507, 508 
(9th Cir. 2017) (complete UZI parts kits ``could `readily be 
converted to expel a projectile by the action of an explosive,' 
meeting the statute's definition of firearm under Sec.  
921(a)(3)(A)'' because the ``kits contained all of the necessary 
components to assemble a fully functioning firearm with relative 
ease''); United States v. Stewart, 451 F.3d 1071, 1072-73, 1073 n.2 
(9th Cir. 2006) (upholding district court's finding that .50 caliber 
rifle kits with incomplete receivers were ``firearms'' under section 
921(a)(3)(A) because they could easily be converted to expel a 
projectile); United States v. Theodoropoulos, 866 F.2d 587, 595 n.3 
(3d Cir. 1989), overruled in part on other grounds by United States 
v. Price, 76 F.3d 526, 528 (3d Cir. 1996) (disassembled machine 
pistol that that could easily be made operable was a firearm under 
section 921(a)(3)(A)); United States v. Morales, 280 F. Supp. 2d 
262, 272-73 (S.D.N.Y. 2003) (partially disassembled Tec-9 pistol 
that could be assembled within short period of time could readily be 
converted to expel a projectile was a firearm under section 
921(a)(3)(A)); United States v. Randolph, No. 02 CR. 850-01 (RWS), 
2003 WL 1461610, at *2 (S.D.N.Y. Mar. 20, 2003) (gun consisting of 
``disassembled parts with no ammunition, no magazine, and a broken 
firing pin, making it incapable of being fired without replacement 
or repair'' was a ``firearm'' under section 921(a)(3)(A) because it 
could be readily converted to expel a projectile and included the 
frame or receiver of such a weapon); cf. United States v. Annis, 446 
F.3d 852, 857 (8th Cir. 2006) (partially disassembled rifle that 
could easily be made operational was a firearm under sentencing 
guidelines); United States v. Ryles, 988 F.2d 13, 16 (5th Cir. 1993) 
(same with disassembled shotgun that could have been readily 
converted to an operable firearm); Enamorado v. United States, No. 
C16-3029-MWB, 2017 WL 2588428, at *6 (N.D. Iowa June 14, 2017) (same 
with disassembled .45 caliber handgun that could easily be 
reassembled).
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B. Definition of ``Frame or Receiver''

    The Department proposed to revise the definition of ``frame or 
receiver'' with a multi-part definition. First proposed was a general 
definition of ``frame or receiver'' with nonexclusive examples that 
illustrated the definition. This was followed by four proposed 
supplements, described below, that further explained the meaning of the 
term ``frame or receiver'' for certain firearm designs and 
configurations. Although the proposed definition was intended to more 
broadly define the term ``frame or receiver'' than the current 
definition, it was not intended to alter any prior determinations by 
ATF regarding which specific part of a given weapon it considered the 
frame or receiver. The NPRM also proposed to codify in the regulations 
the factors ATF considers when classifying the frame or receiver of a 
firearm.
1. General Definition of ``Frame or Receiver''
    As a threshold matter, the NPRM proposed that the new definition, 
with a partial exception for an internal frame or chassis, make clear 
that each frame or receiver be visible to the exterior when the 
complete weapon is assembled so that licensees and law enforcement can 
quickly and easily identify the markings. Next, the NPRM proposed 
defining the term ``frame or receiver'' more broadly as a part that 
provides housing or a structure designed to hold or integrate any fire 
control component, which would have included, at a minimum, any housing 
or holding structure for a hammer, bolt, bolt carrier, breechblock, 
cylinder, trigger mechanism, firing pin, striker, or slide rails. 
However, the proposed definition would not have been limited to those 
particular fire control components \45\ and was proposed to be general 
enough to encompass changes in technology and parts terminology. For 
further clarity, four nonexclusive examples with illustrations of 
common single-framed firearms were provided. See 86 FR at 27727, 27742. 
Finally, the proposed definition stated that persons who may acquire or 
possess a part now defined as a frame or receiver that is identified 
with a serial number must presume, absent an official determination by 
ATF or other reliable evidence to the contrary, that the part is a 
firearm frame or receiver without further guidance.
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    \45\ The prefatory paragraph to the definitional sections in the 
GCA and NFA regulations explain that ``[t]he terms `includes' and 
`including' do not exclude other things not enumerated which are in 
the same general class or are otherwise within the scope thereof.'' 
27 CFR 478.11, 479.11.
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2. Definition of ``Firearm Muffler or Silencer Frame or Receiver''
    The first proposed supplement to define the term ``frame or 
receiver'' as it applies to a ``firearm muffler or silencer frame or 
receiver'' and to add a new term ``complete muffler or silencer 
device'' is further discussed in Section III.D of this preamble. The 
NPRM proposed that in the case of a firearm muffler or firearm 
silencer, the frame or receiver is a part of the firearm that is 
visible from the exterior of a completed device and provides a housing 
or a structure designed to hold or integrate one or more essential 
internal components of the device.
    As described in Section II.C of this preamble, the GCA's marking 
requirement and the GCA/NFA's definition of firearm ``muffler or 
silencer'' (sometimes referred to as a ``sound suppressor'') and its 
marking requirements have caused confusion and concern among many 
silencer manufacturers over the years. The NPRM explained that some 
silencer parts defined as ``silencers,'' such as baffles, are difficult 
for manufacturers to mark and listed examples of the ATF forms that 
manufacturers would have difficulty filing and processing in a timely 
manner. 86 FR at 27728. The Department also explained that it makes 
little sense to mark all silencer parts for tracing purposes when the 
outer tube or housing of the complete device is marked and registered. 
Id. at 27727-28.
    For these reasons, the new definitions were proposed to clarify for 
manufacturers and makers of complete muffler or silencer devices that 
they need only mark the one part of the device defined as the frame or 
receiver under the proposed rule. However, individual muffler or 
silencer parts were proposed to be marked if they are disposed of 
separately from a complete

[[Page 24663]]

device unless transferred by manufacturers qualified under the NFA to 
other qualified licensees for the manufacture or repair of complete 
devices.\46\
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    \46\ This rule is consistent with ATF enforcement policy. See 
footnote 58, infra.
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3. Definition of ``Split or Modular Frame or Receiver''
    The second proposed supplement to the general definition sought to 
capture the majority of firearms that now use a split design as 
discussed above. It sought to clarify that even though a firearm, 
including a silencer, may have more than one part that falls within the 
definition of ``frame or receiver,'' ATF may classify a specific part 
or parts to be the ``frame or receiver'' of a particular weapon. It 
then set forth the various factors ATF would consider in making this 
determination with no single factor controlling. See 86 FR at 27728-29, 
27743. It also proposed the clarification that ``[f]rames or receivers 
of different weapons that are combined to create a similar weapon each 
retain their respective classifications as frames or receivers provided 
they retain their original design and configuration.'' Id. at 27734.
    To ensure that the proposed definition of ``split or modular frame 
or receiver'' did not affect existing ATF classifications that 
specified a single component as the frame or receiver, the definition 
included a nonexclusive list of common weapons with a split or modular 
frame or receiver configuration for which ATF previously determined a 
specific part to be the frame or receiver. See id. at 27729, 27743-46. 
The NPRM explained that a manufacturer or importer of one of these 
firearm designs, as they would exist as of the final rule's date of 
publication, could refer to this list to know which part is the frame 
or receiver, thereby allowing the manufacturer or importer to mark a 
single part without seeking a determination from ATF. However, if there 
was to be a present or future split or modular design for a firearm 
that was not comparable to an existing classification, then the 
proposed definition of ``frame or receiver'' would advise, absent a 
variance or classification from ATF, that more than one part is the 
frame or receiver subject to marking and other requirements.
4. Definition of ``Partially Complete, Disassembled, or Inoperable 
Frame or Receiver''
    The third supplement proposed to define ``frame or receiver'' as 
including frames or receivers that are partially complete, 
disassembled, or inoperable, or a frame or receiver that has reached a 
stage in manufacture where it may readily be completed, assembled, 
converted, or restored to a functional state. The NPRM stated that, to 
determine this status, ``the Director may consider any available 
instructions, guides, templates, jigs, equipment, tools, or marketing 
materials.'' 86 FR at 27729, 27746. ``Partially complete,'' for 
purposes of this definition, was proposed to mean a forging, casting, 
printing, extrusion, machined body, or similar article at a stage in 
manufacture where it is clearly identifiable as an unfinished component 
part of a weapon.
    The NPRM explained that this supplemental definition aimed to 
address when an object becomes a frame or receiver such that it is a 
regulated article. The NPRM stated that partially complete or 
unassembled frames or receivers, commonly called ``80% receivers,'' 
\47\ are often sold in kits where the frame or receiver can readily be 
completed or assembled to a functional state. See id. at 27729 n.54. 
The Department stated that the supplemental definition is necessary for 
clarity because companies are not running background checks or 
maintaining transaction records when they manufacture and sell these 
kits. Accordingly, prohibited persons have easily obtained them \48\ 
and, when recovered, they are nearly impossible to trace. The proposed 
definition also sought to make clear that unformed blocks of metal, and 
other similar articles only in a primordial state \49\ would not--
without more processing--be considered a ``partially complete'' frame 
or receiver that is captured under the definition of ``frame or 
receiver.''
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    \47\ The term ``80% receiver'' is a term used by some industry 
members, the public, and the media to describe a frame or receiver 
that has not yet reached a stage of manufacture to be classified as 
a ``frame or receiver'' under Federal law. However, that term is 
neither found in Federal law nor accepted by ATF.
    \48\ See 86 FR at 27729 n.55; see also Gene Johnson, Felon on 
supervision accused of having `ghost gun' arsenal, Associated Press 
(Feb. 28, 2020), available at https://apnews.com/article/cc61d48e83a2c8113cdb1e1ed6fe6006 (last visited Mar. 23, 2022); Sarah 
Cassi, Lehigh Valley felon was using 3D printer to make `ghost guns' 
at home, Pa. attorney general says,LehighValleyLive.com (June 29, 
2021), available at https://www.lehighvalleylive.com/northampton-county/2021/06/lehigh-valley-felon-was-using-3d-printer-to-make-ghost-guns-at-home-pa-attorney-general-says.html (last visited Mar. 
23, 2022); Deputy recovers `ghost gun' from convicted felon during 
traffic stop, Fontana Herald News (Aug. 10, 2021), available at 
https://www.fontanaheraldnews.com/news/inland_empire_news/deputy-recovers-ghost-gun-from-convicted-felon-during-traffic-stop/article_3cfe0fd0-f4a3-11eb-bd31-03979dc83307.html (last visited Mar. 
23, 2022); Parolee Arrested With AR-15 Ghost Gun, Fake Law 
Enforcement Badge, NBC Palm Springs (Aug. 13, 2021), available at 
https://nbcpalmsprings.com/2021/08/13/parolee-arrested-with-ar-15-ghost-gun-fake-law-enforcement-badge (last visited Mar. 23, 2022); 
Georgetown Arrest of a Felon Leads to Recovery of Ghost Gun, Seattle 
Police Department (Nov. 8, 2021), available at https://spdblotter.seattle.gov/2021/11/08/georgetown-arrest-of-a-felon-leads-to-recovery-of-ghost-gun (last visited Mar. 23, 2022).
    \49\ As used in this rule, the term ``primordial'' refers to an 
item, such as an unmachined block of metal, liquid polymer, or other 
raw material that is in its original natural form or at an early 
stage of development without substantial processing. See Primordial, 
Oxford English Dictionary, available at https://www.oed.com/view/Entry/151373?redirectedFrom=primordial#eid (last visited Mar. 23, 
2022) (``that [which] constitutes the origin or starting point from 
which something else is derived or developed'').
---------------------------------------------------------------------------

5. Definition of ``Destroyed Frame or Receiver''
    The fourth supplement proposed to exclude from the definition of 
``frame or receiver'' any frame or receiver that has been destroyed. 
This proposed definition described a destroyed frame or receiver as one 
permanently altered not to provide housing or a structure that may hold 
or integrate any fire control or essential internal component, and that 
may not readily be assembled, completed, converted, or restored to a 
functional state. The proposed definition set forth nonexclusive 
acceptable methods of destruction, which had been provided by ATF in 
its past guidance.\50\
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    \50\ See 86 FR at 27729, 27746.
---------------------------------------------------------------------------

C. Definition of ``Readily''

    The Department proposed to add the term ``readily'' to 27 CFR 
478.11 and 479.11 and define it as ``a process that is fairly or 
reasonably efficient, quick, and easy, but not necessarily the most 
efficient, speedy, or easy process.'' 86 FR at 27730, 27747, 27751. It 
further listed factors relevant in applying this proposed definition, 
such as time, ease, expertise, equipment, availability, expense, scope, 
and feasibility, with brief examples describing these factors. Id. The 
proposed definitions and factors are based on case law interpreting 
``may readily be converted to expel a projectile'' in 18 U.S.C. 
921(a)(3)(A) and ``can be readily restored to shoot'' in 26 U.S.C. 
5845(b)-(d). See id. at 27730 & n.58. The NPRM explained that defining 
the term ``readily'' was necessary to determine when a weapon, 
including a weapon parts kit, a partially complete or damaged frame or 
receiver, or an aggregation of weapon parts becomes a ``firearm'' 
regulated under the GCA and NFA.

[[Page 24664]]

D. Definitions of ``Complete Weapon'' and ``Complete Muffler or 
Silencer Device''

    The Department proposed to add the terms ``complete weapon'' and 
``complete muffler or silencer device'' to 27 CFR 478.11 and 479.11. 
The proposed definition of a ``complete weapon'' was a firearm, whether 
or not assembled or operable, containing all component parts necessary 
to function as designed but not a firearm muffler or silencer device. 
86 FR at 27730. The proposed definition of a ``complete muffler or 
silencer device'' was a firearm muffler or firearm silencer, whether or 
not assembled or operable, containing all of the component parts 
necessary to function as designed. Id. These terms were proposed to 
explain when a frame or receiver of a firearm, including a firearm 
muffler or silencer, as the case may be, must be marked for 
identification.

E. Definition of ``Privately Made Firearm''

    The NPRM proposed adding the term ``privately made firearm'' to 27 
CFR 478.11 and to define it as a firearm, including a frame or 
receiver, assembled by a person other than a licensed manufacturer, and 
not containing a serial number or other identifying marking placed by a 
licensed manufacturer at the time the firearm was produced. See 86 FR 
at 27730. The term would not include a firearm identified and 
registered in the NFRTR pursuant to 26 U.S.C., chapter 53, or any 
firearm made before October 22, 1968 (unless remanufactured after that 
date).\51\
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    \51\ The Federal Firearms Act of 1938 (repealed), the 
predecessor to the GCA, made it unlawful for a person to receive in 
interstate or foreign commerce a firearm that had the manufacturer's 
serial number removed, obliterated, or altered. 15 U.S.C. 902(i) 
(1940). Regulations promulgated to implement this law required each 
firearm manufactured after July 1, 1958, to be identified with the 
name of the manufacturer or importer, a serial number, caliber, and 
model. However, there was an exception from the serial number and 
model requirements for any shotgun or .22 caliber rifle unless that 
firearm was also subject to the NFA. 26 CFR 177.50 (1959) 
(rescinded).
---------------------------------------------------------------------------

F. Definition of ``Importer's or Manufacturer's Serial Number''

    The Department proposed to add the term ``importer's or 
manufacturer's serial number'' in 27 CFR 478.11 and to define it as the 
identification number, licensee name, licensee city or State, or 
license number placed by a licensee on a firearm frame or receiver or 
on a PMF. The NPRM explained that a serial number incorporating the 
abbreviated FFL number (also known in industry as the ``RDS key'') 
placed by a licensee on a PMF under the proposed rule met the 
definition of the ``importer's or manufacturer's serial number.'' The 
Department also explained that the proposed definition would help 
ensure that the serial numbers and other markings necessary to ensure 
tracing are considered the ``importer's or manufacturer's serial 
number'' protected by 18 U.S.C. 922(k) and numerous State laws, which 
prohibit possession of firearms with serial numbers that have been 
removed, obliterated, or altered. See 86 FR at 27730 n.62.

G. Definition of ``Gunsmith'' \52\
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    \52\ The term ``gunsmith'' is not used in the GCA; however, the 
Firearm Owners' Protection Act, Public Law 99-308 (1986), amended 
the GCA to define ``engaged in the business'' as applied to dealers 
to clarify when gunsmiths must have a license. See 18 U.S.C. 
921(a)(11)(B), (a)(21)(D); 132 Cong. Rec. 9603-04 (1986) (statement 
of Sen. McClure).
---------------------------------------------------------------------------

    The Department proposed to amend the definition of ``engaged in the 
business'' as it applies to a ``gunsmith'' in 27 CFR 478.11 to clarify 
that businesses may be licensed as dealer-gunsmiths rather than as 
manufacturers if they routinely repair or customize existing firearms, 
make or fit special barrels, stocks, or trigger mechanisms, or mark 
firearms as a service performed on firearms not for sale or 
distribution by a licensee.\53\ The proposed amendment was also for the 
purpose of providing greater access to professional marking services so 
that persons who engage in the business of identifying firearms for 
nonlicensees may become licensed as dealer-gunsmiths solely to provide 
professional PMF marking services.
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    \53\ This rule would supersede ATF Ruling 2010-10, which allows 
gunsmiths under specified conditions to engage in certain 
manufacturing activities for licensed manufacturers. This change was 
proposed to eliminate a significant source of confusion among 
regulated industry members and the public as to who needs a license 
to manufacture firearms. See Broughman v. Carver, 624 F.3d 670 (4th 
Cir. 2010) (distinguishing dealer-gunsmiths from manufacturers).
---------------------------------------------------------------------------

H. Marking Requirements for Firearms

1. Information Required to be Marked on the ``Frame or Receiver''
    To properly implement the new definitions, the Department proposed 
to amend 27 CFR 478.92(a) and 479.102 to explain how and when markings 
must be applied on each part defined as a frame or receiver, 
particularly since there could have been more than one part of a 
complete weapon, or complete muffler or silencer device, which is the 
frame or receiver (i.e., when ATF has not identified specific part(s) 
as the frame or receiver). Under the NPRM, each frame or receiver of a 
new firearm design or configuration manufactured or imported after the 
publication of the final rule was proposed to be marked with a serial 
number, and either: (a) The manufacturer's or importer's name (or 
recognized abbreviation), and city and State (or recognized 
abbreviation) where the manufacturer or importer maintains their place 
of business, or in the case of a maker of an NFA firearm, where the 
firearm was made; or (b) the manufacturer's or importer's name (or 
recognized abbreviation), and the serial number beginning with the 
licensee's abbreviated FFL number as a prefix, which is the first three 
and last five digits, followed by a hyphen, and then followed by a 
number (which may incorporate letters and a hyphen) as a suffix, e.g., 
``12345678-[number].'' The serial number (with or without the FFL 
prefix) identified on each part of a weapon defined as a frame or 
receiver was proposed to be the same number, but could not duplicate 
any serial number(s) placed by the licensee on any other firearm.
    The NPRM proposed that licensed manufacturers and importers could 
continue to identify the additional information on firearms (other than 
PMFs) of the same design and configuration as they existed before the 
effective date of the final rule under the prior content rules, and any 
rules necessary to ensure such identification would have remained 
effective for that purpose. This proposed provision was intended to 
make the transition easier and reduce production costs incurred by 
licensees.
    Except for silencer parts transferred by manufacturers to other 
qualified manufacturers and dealers for completion or repair of 
devices, no change was proposed to the existing requirement that each 
part defined as a machinegun or silencer that is disposed of separately 
and not part of a complete weapon or device be marked with all required 
information, because individual machinegun conversion and silencer 
parts are ``firearms'' under the NFA that must be registered in the 
NFRTR. 26 U.S.C. 5841(a)(1), 5845(a), (b). However, for frames and 
receivers, and individual machinegun conversion or silencer parts 
defined as ``firearms'' that are disposed of separately, the proposed 
rule allowed the model designation and caliber or gauge to be omitted 
if it is unknown at the time the part is identified. See 86 FR at 
27731.
2. Size and Depth of Markings
    The Department did not propose changes to the existing requirements 
for size and depth of markings in 27 CFR

[[Page 24665]]

478.92(a)(1) and 479.102(a), but for sake of clarity, proposed to 
consolidate them into a standalone paragraph.
3. Period of Time To Identify Firearms
    The Department proposed to identify the point at which 
manufacturers would be required to place markings on firearms. The NPRM 
proposed that complete weapons or complete muffler or silencer devices, 
as defined in the rule, would be allowed to be marked up to seven days 
from completion of the active manufacturing process for the weapon or 
device, or prior to disposition, whichever is sooner. Except for 
silencer parts produced by qualified manufacturers for transfer to 
other licensees to complete or repair silencer devices, parts defined 
as a frame or receiver, machinegun, or firearm muffler or firearm 
silencer that are not component parts of a complete weapon or device 
when disposed of would be allowed to be marked up to seven days 
following the date of completion of the active manufacturing process 
for the part, or prior to disposition, whichever is sooner. Adding this 
proposed language would codify ATF Ruling 2012-1, which explained that, 
whether the end product is to become a complete weapon or device, or a 
frame or receiver to be disposed of separately, it is reasonable for a 
licensed manufacturer to have seven days following the date of 
completion of the entire manufacturing process in which to mark a 
firearm manufactured and record its identifying information in the 
manufacturer's permanent records.
4. Marking of ``Privately Made Firearms''
    The Department proposed to amend 27 CFR 478.92 to require FFLs to 
mark, or supervise the marking of, the same serial number on each part 
of the weapon defined as frame or receiver (as defined in the rule) of 
a PMF that the licensee acquired, but not duplicate any serial 
number(s) placed on any other firearm. The marking would begin with the 
FFL's abbreviated license number (first three and last five digits) as 
a prefix, followed by a hyphen, and then followed by a number as a 
suffix (e.g., ``12345678-[number]''). Unless previously identified by 
another licensee, PMFs acquired by licensees on or after the effective 
date of the rule were proposed to be marked in this manner within seven 
days of receipt or other acquisition (including from a personal 
collection), or before the date of disposition (including to a personal 
collection), whichever is sooner.\54\ For PMFs acquired by licensees 
before the effective date of the rule, the proposed rule would require 
licensees to mark or cause them to be marked by another licensee either 
within 60 days from the effective date of a final rule, or before the 
date of final disposition (including to a personal collection), 
whichever is sooner.\55\
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    \54\ Under this rule, licensed collectors would only need to 
mark PMFs they receive that are defined as ``curios or relics.'' See 
27 CFR 478.11 (definitions of ``firearm'' and ``curios or relics'').
    \55\ Handguns that are 3D-printed are also subject to the 
registration and taxation requirements of the NFA if they have a 
smooth bore and are capable of being concealed on the person, 
thereby falling within the definition of ``any other weapon'' under 
the NFA. See 26 U.S.C. 5845(e).
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    Consistent with the language and purpose of the GCA, the NPRM 
explained that this proposed provision was necessary to allow ATF to 
trace all firearms acquired and disposed of by licensees, prevent 
illicit firearms trafficking, and provide procedures for FFLs and the 
public to follow with respect to PMF transactions with the licensed 
community. The proposed rule further noted that this provision was 
crucial in light of advances in technology that allow unlicensed, 
including prohibited, persons easily and repeatedly to produce firearms 
at home from parts ordered online, or by using 3D printers or 
personally owned or leased equipment. Such privately made firearms have 
made and will continue to make their way to the primary market in 
firearms through the licensed community.\56\
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    \56\ Under Federal law, for example, certain firearm 
transactions must be conducted through FFLs. See 18 U.S.C. 922(a)(5) 
(prohibiting any person other than a licensee, subject to certain 
limited exceptions, from selling or delivering a firearm to an 
unlicensed out-of-state resident).
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    At the same time, nothing in the proposed rule restricted persons 
who are not otherwise prohibited from possessing firearms from making 
their own firearms without markings solely for personal use, nor did 
the proposed rule require individuals to mark PMFs when they 
occasionally acquire them for a personal collection, or sell or 
transfer them from a personal collection to unlicensed in-State 
residents in accordance with Federal, State, and local law. Further, 
the NPRM would not require FFLs to accept any PMFs, or to mark PMFs 
themselves, or to provide services to place identification marks on 
PMFs. Licensees would be able to arrange for individuals who wish to 
transfer PMFs to licensees to have them marked by another licensee 
before accepting them, provided they are properly marked in accordance 
with the proposed rule.
5. Meaning of Marking Terms
    An additional amendment to 27 CFR 478.92 and 478.102 was proposed 
to clarify the meaning of the terms ``legible'' and ``legibly'' to 
ensure that ``the identification markings use exclusively Roman letters 
(e.g., A, a, B, b, C, c) and Arabic numerals (e.g., 1, 2, 3), or solely 
Arabic numerals, and may include a hyphen,'' and that the terms 
``conspicuous'' and ``conspicuously'' are understood to mean that the 
identification markings are capable of being easily seen and 
unobstructed by other markings when the firearm is assembled. 86 FR at 
27733. These would clarify the meaning of those terms as explained in 
ATF Ruling 2002-6 (``legible''), and ATF's final rule at 66 FR 40599 
(Aug. 3, 2001) (referencing U.S. Customs Service regulations on the 
definition of ``conspicuous'').
6. Alternate Means or Period of Identification
    The proposed rule would not alter the Director's existing ability 
to authorize other means of identification, or a ``marking variance,'' 
for any part defined as a firearm (including a machinegun or a 
silencer), or the process for such a variance.
7. Destructive Device Period of Identification
    The proposed rule specified a seven-day grace period in which to 
mark all completed firearms, including destructive devices (similar to 
other firearms), and would have allowed ATF to grant a variance from 
this period. There were no proposed changes to the marking requirements 
for destructive devices.
8. Adoption of Identifying Markings
    The Department proposed allowing licensed manufacturers and 
importers to adopt an existing serial number, caliber/gauge, model, or 
other markings already identified on a firearm, provided that they 
legibly and conspicuously place, or cause to be placed, on each part 
(or part(s)) defined as a frame or receiver, either the FFL's name (or 
recognized abbreviation), and city and State (or recognized 
abbreviation) where they maintain their place of business; or their 
name (or recognized abbreviation) and their abbreviated FFL number, as 
described in Section III.H.1 of this preamble, followed by the existing 
serial number (including any other abbreviated FFL prefix) as a suffix, 
e.g., ``12345678-[serial number],'' to ensure the traceability of the 
firearm. This language was proposed to supersede ATF Ruling 2013-3 as 
it applied to licensed manufacturers and importers.

[[Page 24666]]

The proposal was aimed at avoiding multiple markings on firearms that 
could be confusing to law enforcement and alleviate concerns of some 
manufacturers and importers regarding serial number duplication when 
firearms are remanufactured or imported.
9. Firearm Muffler or Silencer Parts Transferred Between Qualified 
Licensees
    Licensed and qualified firearm muffler or silencer manufacturers 
routinely transfer small internal muffler or silencer components to 
each other to produce complete devices. Licensees qualified under the 
NFA routinely do the same when repairing existing devices. Because of 
the difficulties and expense of marking and registering small 
individual components used to commercially manufacture a complete 
muffler or silencer device with little public safety benefit, the NPRM 
proposed to allow qualified manufacturers to transfer parts defined as 
a firearm muffler or silencer to other qualified manufacturers without 
immediately identifying or registering them. Once the new device was 
completed with the part, the manufacturer would be required to identify 
and register the device in the manner and within the period specified 
in the proposed rule for a complete device. Likewise, the NPRM proposed 
to allow qualified manufacturers to transfer muffler or silencer 
replacement parts to qualified manufacturers and dealers to repair 
existing devices already identified and registered in the NFRTR. 
Further, the rule proposed to amend the definition of ``transfer'' to 
clarify that temporary conveyance of a lawfully possessed NFA firearm, 
including a silencer, to a qualified manufacturer or dealer for the 
sole purpose of repair, identification, evaluation, research, testing, 
or calibration, and return to the same lawful possessor is not a 
``transfer'' requiring additional identification or registration in the 
NFRTR.\57\ The proposed changes were intended to reduce the practical 
and administrative problems of marking and registering silencer parts 
by the regulated industry, and to avoid a potential resource burden on 
ATF to process numerous tax-exempt registration applications with 
little public safety benefit.\58\
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    \57\ The definition of ``transfer'' in the NFA only includes 
``selling, assigning, pledging, leasing, loaning, giving away, or 
otherwise disposing of'' a firearm. 26 U.S.C. 5845(j); see also 
United States v. Smith, 642 F.2d 1179, 1182 (9th Cir. 1981) (``We 
cannot agree that Congress intended to impose a transfer tax and 
require registration whenever mere physical possession of a firearm 
is surrendered for a brief period.'').
    \58\ These changes are consistent with ATF enforcement policy. 
See NFA Handbook, ATF E-Publication 5320.8, sec. 7.4.6, p.46, sec. 
9.5.1, p. 60 (revised April 2009). With regard to silencer repairs, 
in order to avoid any appearance that an unlawful ``transfer'' has 
taken place, ATF recommends that an Application for Tax Exempt 
Transfer and Registration of Firearm, ATF Form 5, be submitted for 
approval prior to conveying the firearm for repair or identifying 
the firearm. The conveyance may also be accomplished by submission 
of a letter from the registrant to the qualified FFL advising the 
FFL that the registrant is shipping or delivering the firearm for 
repair/identification and describing the repair or identification. 
Return of the registered silencer to the registrant may likewise be 
accomplished by submission of an ATF Form 5 or by a letter from the 
FFL to the registrant that accompanies the silencer.
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10. Voluntary Classification of Firearms and Armor Piercing Ammunition
    As described in the NPRM, for many years, ATF has acted on 
voluntary requests from persons, particularly manufacturers who are 
developing new products, by issuing determinations or 
``classifications'' on whether an item is a ``firearm'' or ``armor 
piercing ammunition'' as defined in the GCA or NFA. The Department 
proposed to clarify the existing process by which persons may 
voluntarily submit such requests to ATF. The NPRM proposed that 
requests be submitted in writing, or on an ATF form, executed under the 
penalties of perjury with a complete and accurate description of the 
item, the name and address of the manufacturer or importer thereof, and 
a sample of such item for examination along with any instructions, 
guides, templates, jigs, equipment, tools, or marketing materials that 
are made available to the purchaser or recipient of the item. Upon 
completion of the examination, ATF would return the sample to the 
person who made the request unless a determination was made that return 
of the sample would be, or place the person, in violation of law. The 
NPRM also proposed to codify ATF's policy of not evaluating a firearm 
accessory or attachment ``unless it is installed on the firearm(s) in 
the configuration for which it is designed and intended to be used,'' 
and further explained that the Director's determination would not be 
applicable to or authoritative with respect to any other sample, 
design, model, or configuration. 86 FR at 27734.

I. Recordkeeping

1. Acquisition and Disposition Records
    The Department proposed minor amendments to 27 CFR 478.122, 
478.123, 478.125, and 478.125a, pertaining to the acquisition and 
disposition records maintained by importers, manufacturers, and 
dealers. Due to the possibility that a firearm may have more than one 
frame or receiver as defined in the proposed rule, and the changes to 
marking regulations, the rule proposed to make certain words plural, 
(e.g., manufacturer(s), importer(s), and serial number(s)) in the 
recordkeeping regulations for the formatting of FFL records, as 
applicable. These proposed changes were considered necessary to ensure 
that FFLs record more than one manufacturer, importer, or serial 
number, if applicable, when acquiring or disposing of firearms with 
multiple components marked as the frame or receiver, or firearms that 
have been remanufactured or reimported by another licensee. This is 
consistent with prior ATF guidance to the firearms industry.\59\
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    \59\ See FFL Newsletter, May 2012, at 5 (``If a firearm is 
marked with two manufacturer's names, or multiple manufacturer and 
importer names, FFLs should record each manufacturers' and 
importers' [sic] name in the A&D record.'').
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    The rule also proposed to amend 27 CFR 478.122 and 478.123 to 
require licensed importers and manufacturers to consolidate their 
records of importation, manufacture, or other acquisition, and their 
sale or other disposition in a format containing the applicable columns 
specified in a table under the regulation. These changes were proposed 
to supersede ATF Rulings 2011-1 and 2016-3.
    The NPRM proposed to make minor clarifying changes to the format of 
the column titles required on the A&D Record in Sec.  478.125(e). The 
proposed change was to make clear that both the name and license number 
(not the address) of a licensee from whom firearms are received and to 
whom they are disposed are recorded properly in the A&D Record.
    The rule also proposed minor changes to Sec.  478.125(f) to make 
clear that in the event the licensee records a duplicate entry with the 
same firearm and acquisition information, whether to close out an old 
record book or for any other reason, the licensee must record a 
reference to the date and location of the subsequent entry (e.g., date 
of new entry, book name/number, page number, and line number) to 
document the disposition. The NPRM explained the proposed change is 
needed to ensure that acquisition records are closed out when firearms 
are no longer in inventory \60\ and would resolve problems that ATF has 
encountered during the inspection process and FFLs

[[Page 24667]]

have encountered when responding to trace requests.
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    \60\ This is consistent with prior ATF guidance to the firearms 
industry. See FFL Newsletter, Sept. 2011, at 5.
---------------------------------------------------------------------------

2. Firearms Transaction Records
    Some technical amendments were proposed at 27 CFR 478.124 
pertaining to information recorded on the Form 4473. Like changes to 
the recordkeeping regulations, the rule proposed to make certain words 
plural on the Form 4473 to ensure that FFLs would record more than one 
manufacturer, importer, and serial number, if applicable. The NPRM also 
proposed to remove from paragraph (f) a phrase that indicates than an 
FFL must fill out the firearm description information only after 
filling out the information about the transferee. The proposed deletion 
would clarify ATF Procedure 2020-1, which sets forth an alternative 
method of complying with section 478.124(f) for non-over-the-counter 
firearm transactions, and reflect the current process for completing 
the Form 4473.
3. Recordkeeping for ``Privately Made Firearms''
    The Department proposed changes to the regulations regarding 
recordkeeping by licensees to account for any voluntary receipts or 
other acquisitions (including from a personal collection) of PMFs, and 
corresponding dispositions (including to a personal collection). If a 
PMF were received or otherwise acquired by a licensee or disposed of, 
or imported, the proposed rule required the abbreviation ``PMF'' to be 
recorded as the manufacturer in the appropriate column, as well as the 
PMF serial number beginning with the abbreviated FFL number in the 
serial number column. The rule proposed requiring licensees to first 
record the PMF as an acquisition in the licensee's A&D records upon 
receipt from the private owner (whether or not the licensee kept the 
PMF overnight). Once marked, the licensee would update the acquisition 
entry with the identifying information and record its return as a 
disposition to the private owner.
4. NFA Forms Update
    The Department proposed minor technical amendments to 27 CFR 
479.62, 479.84, 479.88, 479.90, and 479.141, pertaining to the 
Application to Make, NFA Form 1 (``Form 1''), the Application to 
Transfer, NFA Form 4 (``Form 4''), Tax Exempt Transfers--SOTs, NFA Form 
3 (``Form 3''), Tax Exempt Transfers--Governmental Entities, NFA Form 5 
(``Form 5''), and the Stolen or Lost Firearms Report, Form 3310.11 
(``Form 3310.11''), respectively. The technical amendments were 
proposed to make certain words on the forms plural (i.e., 
manufacturer(s), importer(s), serial number(s)).
5. Importation Forms Update
    The Department proposed minor technical amendments to 27 CFR 
447.42, 447.45, 478.112, 478.113, 478.114, and 479.112, pertaining to 
the importation of firearms. Like the other recordkeeping changes, 
these technical amendments were proposed to ensure that more than one 
name, manufacturer, country, importer, or serial number, if applicable, 
would be recorded when completing importation forms.

J. Record Retention

    Given advancements in electronic scanning and storage technology, 
ATF's acceptance of electronic recordkeeping, the reduced costs of 
storing firearm transaction records, the increased durability and 
longevity of firearms, and the public safety benefits of ensuring that 
records of active licensees are available for tracing purposes, the 
Department proposed to amend 27 CFR 478.129 to require FFLs to retain 
all records until business or licensed activity is discontinued, either 
on paper or in an electronic format approved by the Director,\61\ at 
the business or collection premises readily accessible for inspection. 
Also, a proposed amendment to 27 CFR 478.50(a) would allow all FFLs, 
including manufacturers and importers, to store paper records and forms 
older than 20 years at a separate warehouse, which would be considered 
part of the business premises for this purpose and subject to 
inspection. These amendments would reverse a 1985 rulemaking allowing 
non-manufacturer/importer FFLs to destroy their records after 20 
years.\62\
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    \61\ ATF previously approved electronic storage of certain 
records under the conditions set forth in ATF Rulings 2016-1 
(Requirements to Keep Firearms Records Electronically) and 2016-2 
(Electronic ATF Form 4473).
    \62\ See Retention of Firearms Transaction Records, 50 FR 26702 
(June 28, 1985).
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IV. Analysis of Comments and Department Responses for the Proposed Rule

    In response to the NPRM, ATF received 290,031 comments. Submissions 
came from individuals, including foreign nationals, lawyers, government 
officials, and various interest groups. Of the comments reviewed, there 
were nearly 114,400 comments that expressed support for the proposed 
rule. Of these, over 68,000 were submitted by individuals as form 
letters, i.e., identical text that is often supplied by organizations 
or found online and recommended to be submitted to the agency as a 
comment. There were nearly 170,550 comments opposed to the rule, of 
which over 88,000 comments were submitted as form letters. For over 
1,500 comments, the commenters' positions could not be determined. The 
commenters' grounds for support and opposition, along with specific 
concerns and suggestions, are discussed below.

A. Issues Raised in Support of the Rule

    Thousands of commenters broadly expressed support for the NPRM. 
Over 3,000 comments simply expressed support, stating ``stop ghost 
guns,'' but numerous other comments focused on the need to regulate 
``ghost guns'' and were supportive of the proposed change to treat 
items like weapon parts kits the same as other firearms because the 
commenters believed such treatment is necessary for public safety. 
These commenters pointed to the rise and proliferation of ``do-it-
yourself'' (``DIY'') firearms used in crimes and argued that it is easy 
for extremists, violent criminals, and traffickers, among others, to 
skirt the law and obtain untraceable guns without undergoing a 
background check. They stated that the rule was necessary to combat the 
emerging threat that ``ghost guns'' pose to public safety.
    As discussed below, numerous other commenters ranging from 
lawmakers to prosecutors to religious, medical, and social policy-
oriented organizations all raised various points as to why they were 
supportive of the Department's proposed amendments to ATF regulations. 
Some commenters in support of the rule also provided suggestions on 
where they believed the regulatory text could be enhanced or further 
clarified.
1. Changes are Consistent With Law
Comments Received
    Commenters in support remarked that the proposed definitions are 
justified given the ease with which prohibited persons can 
intentionally circumvent Federal regulations to acquire unfinished 
frames or receivers that can be easily converted to functional firearms 
without a background check. Commenters agreed that ATF's proposed 
definitions are consistent with Congress's intent to regulate the core 
component of the firearm and that the plain meaning of ``firearm'' in 
the GCA includes any kits or nearly complete frames or receivers that 
can be readily converted into a firearm. One commenter noted the case 
United States v. Drasen, 845 F.2d 731, 736-37 (7th Cir. 1988), where 
the Seventh Circuit rejected the argument that a collection

[[Page 24668]]

of rifle parts cannot be a ``weapon.'' Other commenters agreed that 
ATF's proposed rule would be a functional definition that preserves 
existing designs while defining the frame or receiver to include those 
with split or multi-piece frame or receiver configurations, and allows 
for flexibility over time to account for new technologies. They stated 
that this flexible approach, including manufacturers' ability to submit 
a firearm to ATF and receive a classification on which component 
constitutes the receiver, would preserve the existing designations that 
ATF has made and minimize the burden on the gun industry.
    Similarly, others agreed that the definition and factors set forth 
for the term ``readily'' are consistent with case law interpreting the 
term, and that the proposed definition and such case law provides 
manufacturers with fair warning on how the factors will be considered. 
Further, some commenters indicated that the proposed ``readily'' test 
is consistent with ATF's past approach to reviewing unfinished 
receivers. Some commenters, such as the Brady Group, the District 
Attorney and County Counsel for the County of Santa Clara, and the 
Attorney General for the State of California stated that for a few 
decades, ATF had issued classification letters taking the position that 
some unfinished receivers, which are identical to the so-called ``80% 
receivers'' on the market today, were ``firearms'' under the GCA. They 
stated that, in that time period, ATF's analysis was based on an 
approach that examined how quickly and easily an unfinished receiver or 
frame could be turned into a fully functional firearm--that is, whether 
it could ``readily be converted'' to function as the firearm it was 
specifically designed to be. The same commenters then asserted that, 
from around 2006 to the present, ATF changed its analysis and began to 
look at which machining operations still needed to be performed to 
determine whether a partially completed receiver or frame is a 
``firearm'' under the GCA. Commenters believed that ATF's change in 
interpretation led to an increase in the number of PMFs that have 
proliferated and that are being recovered in crime scenes.
Department Response
    The Department acknowledges the commenters' support for the 
proposed rule. The definitions in the proposed rule are consistent with 
the plain meaning of the term ``firearm'' in the GCA as it includes 
frames or receivers of weapons that are designed to or may readily be 
converted to fire, not merely of weapons that are in a functional state 
that will expel a projectile. The Department agrees with commenters 
that any new definitions must be general enough to account for changes 
in technology and terminology while preserving ATF's past 
classifications to minimize the impact on the firearms industry. The 
Department further agrees that the proposed definition of the term 
``readily'' is consistent with case law that provides manufacturers 
with fair warning on how the factors in that definition are evaluated.
    The Department also agrees that ATF took the position in past 
classification letters that some unfinished receivers were firearms 
because of the ease with which they can be made functional. However, 
ATF disagrees with commenters who stated that ATF changed its position 
from 2006 to the present concerning partially complete frames or 
receivers when it determined that specific machining operations had to 
be performed with respect to certain partially complete frames or 
receivers. Rather than a new or different test, how quickly and easily 
an item could be made functional is largely determined by which 
machining operations still needed to be performed. ATF has maintained 
and continues to maintain that a partially complete frame or receiver 
alone is not a frame or receiver if it still requires performance of 
certain machining operations (e.g., milling out the fire control cavity 
of an AR-15 billet or blank, or indexing for that operation) because it 
may not readily be completed to house or hold the applicable fire 
control components. When a frame or receiver billet or blank is indexed 
or ``dimpled,'' it indicates the location for drilling or milling the 
holes or cavities necessary to install the fire control components 
necessary to initiate, complete, or continue the firing cycle.
    However, this rule recognizes that the aggregation of a template or 
jig with a partially complete frame or receiver can serve the same 
purpose as indexing, making an item that is clearly identifiable as a 
partially complete frame or receiver into a functional one efficiently, 
quickly, and easily (i.e., ``readily''). Prior to this rule, ATF did 
not examine templates, jigs, or other items and materials in 
determining whether partially complete frames or receivers were 
``firearms'' under the GCA. For this reason, ATF issued some 
classifications concluding that certain partially complete frames or 
receivers were not ``frames or receivers'' as defined in this rule. 
Thus, any classification requests for partially complete, disassembled, 
or nonfunctional items or parts kits that were previously submitted to 
ATF, particularly those submitted without their associated templates, 
jigs, molds, instructions, equipment, or marketing materials as 
required by this rule, must be re-evaluated consistent with this rule 
to determine whether they would now be classified as ``firearms,'' 
``frames,'' or ``receivers.''
2. Enhances Public Safety
Comments Received
    Commenters supporting the proposed rule argued that the proposed 
rule is needed to make communities safer because under-regulation has 
made the rise of so-called ghost guns the fastest-growing public safety 
threat in the country. Some commenters emphasized that women who are 
victims of domestic abuse are severely affected by the rapid 
proliferation of unserialized firearms that can be easily acquired 
without a background check by convicted domestic violence offenders or 
those subject to a domestic violence restraining order. Healthcare and 
physicians' organizations, which have called gun violence a public 
health epidemic, urged issuance of the proposed rule as a necessary 
step to reduce or prevent firearm-related injuries and death.
    Various commenters, including Members of Congress, State lawmakers, 
and State and local prosecutors noted the uptick in the involvement of 
``ghost guns'' in crimes and provided numbers demonstrating the rise of 
unserialized firearms recovered or used in crimes in their 
jurisdictions. For example, a comment from several State Attorneys 
General asserted that the Philadelphia Police Department recovered 287 
unserialized guns in the first half of 2021, whereas in 2019, the 
Philadelphia police recovered just 95 unserialized guns, and that 
unserialized guns represented 2.23 percent of all guns recovered after 
gun crimes. Similarly, a comment from the Gun Violence Task Force of 
the New York County Lawyers Association asserted that in 2020, law 
enforcement in New York recovered 220 ``ghost guns'' compared to 72 in 
2019, and 38 in 2018. They stated that this represented a 479 percent 
increase over a three-year period. One group asserted that law 
enforcement officers across the country are increasingly identifying 
trafficking rings that mass produce and sell untraceable firearms. 
These commenters stated that it is important to take proactive steps 
now, given that technology continues to rapidly evolve and makes it 
likely that these weapons will become easier and cheaper to

[[Page 24669]]

manufacture privately, especially for criminals intending to skirt the 
law.
Department Response
    The Department acknowledges that the rule will enhance public 
safety by helping to ensure that more firearms may be traced by law 
enforcement to solve crime and arrest the perpetrators. As discussed in 
Section II.B of this preamble, ATF has also seen an exponential 
increase in the number of suspected PMFs recovered and reported for 
tracing. At the same time, by requiring sellers to have licenses and 
conduct background checks when firearm parts kits are manufactured and 
sold, the rule will help prevent potentially dangerous persons from 
acquiring those kits and easily making functional weapons.
3. Prevents Companies From Exploiting Loopholes
Comments Received
    Many commenters in support of the proposed rule argued that it was 
necessary to regulate so-called ghost guns because they believe that 
the primary reason people acquire them is for illicit purposes and that 
companies are exploiting existing loopholes in Federal regulations. 
Other commenters indicated that companies making and advertising DIY 
kits intentionally target prohibited purchasers or other dangerous 
parties by emphasizing the untraceable nature of their products. These 
companies, the commenters pointed out, frequently use the absence of a 
serial number and the ability to purchase the gun without a background 
check as selling points. Accordingly, these commenters argued it is 
evident that PMFs are not being used purely by hobbyists but are 
instead being made and sold for use on the street by violent criminals 
and gun traffickers precisely because their acquisition falls outside 
the scope of existing Federal regulations.
    Some commenters made reference to ATF's Ruling 2015-1 that 
addressed inquiries from the public asking whether FFLs, or unlicensed 
machine shops, may engage in the business of completing, or assisting 
in the completion of, the manufacture of ``firearm frames or 
receivers'' (specifically from castings or blanks) for unlicensed 
individuals without becoming licensed as a manufacturer. These 
commenters asserted that the ``ghost gun industry'' ensures that its 
handgun frames and semiautomatic receivers do not meet ATF's 2015 
interpretation of ``frame or receiver'' simply by not drilling into the 
frame or receiver, shipping the mostly finished item to the purchaser, 
and providing detailed instructions on how to complete the firearm 
privately, often within minutes. This allows the industry to sell 
thousands of weapons with no serial numbers or background checks. One 
commenter emphasized the proposed multi-factor analysis for ``readily'' 
provides ATF with the necessary flexibility to adapt to innovations in 
firearms technology and likely prevents these parts kits manufacturers 
from developing products aimed at complying with a narrow construction 
of ATF regulations while skirting the spirit and intent of the GCA.
Department Response
    The Department acknowledges the commenters' support for the 
proposed rule. This rule interprets the plain language of the GCA to 
update its regulations and clarify when a license is required, which 
part of a firearm must be marked, and what records must be maintained 
by licensees. The rule clarifies that the regulatory definitions of 
``firearm'' and ``frame or receiver'' include weapon and frame or 
receiver kits with partially complete frames or receivers, which are 
therefore subject to regulatory controls under the GCA or NFA. Sellers 
of such parts kits are required to be licensed, and the frames or 
receivers of those firearms must be marked with a serial number and 
other identifying information. ATF anticipates that, as technology 
develops, this rule will help to ensure that persons who commercially 
produce partially complete frames or receivers that can efficiently, 
quickly, and easily be completed are licensed and conduct background 
checks when sold to unlicensed individuals. This will help prevent 
prohibited persons from acquiring such frames and receivers.
4. Regulates ``Privately Made Firearms'' Like Other Firearms
Comments Received
    Numerous commenters stated that PMFs should be regulated the same 
as any other firearm to ensure that manufacturers of weapon parts kits 
are licensed, adhere to recordkeeping requirements, and perform 
background checks on the purchasers of their products. Many commenters, 
including lawmakers from States such as Maryland, Massachusetts, and 
New York, stated that although some States that have enacted, or are 
working to pass, legislation regulating the possession or making of 
unserialized firearms, these laws cannot work in a vacuum and that 
there are limits to what any one State can do. Less restrictive gun 
laws in neighboring States, they argued, undermine States with tighter 
restrictions. Unserialized firearms and unfinished frames and receivers 
will continue to flow into their communities. Federal regulation, they 
argued, is therefore needed to close the loophole; otherwise, law 
enforcement and State efforts to prevent gun violence and enforce their 
own laws will be severely undermined. For example, the County of Santa 
Clara District Attorney wrote that the lack of adequate serialization 
and recordkeeping of PMFs has made it difficult for law enforcement to 
apprehend individuals involved in ongoing criminal activity or firearms 
traffickers who supply criminals with weapons. Similarly, another 
prosecutors' organization stated that prosecutors rely on gun markings 
to generate leads and identify patterns, and the lack of serial numbers 
on PMFs undermines prosecutors' ability to effectively investigate and 
prosecute gun crime.
    Lastly, some commenters stated that ATF should reject the 
inaccurate claims that the NPRM would make criminals out of law-abiding 
gun owners, stating that the rule would not reach or restrict private 
individuals legally allowed to possess a firearm who previously 
purchased nearly complete frames or receivers or ghost gun kits. These 
individuals, they argued, will be no more exposed to criminal liability 
than they are currently. They concluded that the NPRM will cut off the 
supply of ghost guns to traffickers and prohibited persons at its 
source and not burden law-abiding, good faith actors.
Department Response
    The Department acknowledges commenters' support for the proposed 
rule, and notes that one of the primary purposes of the GCA is to 
assist State and local jurisdictions to control the traffic of firearms 
within their own borders through the exercise of their police 
power.\63\ Under the rule as proposed and finalized, when licensees 
receive privately made or DIY firearms in the course of their licensed 
business or activity, they will need to mark or cause those firearms to 
be marked. This allows PMFs to be traceable by State and local law 
enforcement whenever they, like commercially produced firearms, are 
introduced into the regulated marketplace. At the same time, neither 
the GCA nor the proposed or final rule prohibits unlicensed

[[Page 24670]]

individuals from marking (non-NFA) firearms they make for their 
personal use, or when they occasionally acquire them for a personal 
collection, or sell or transfer them from a personal collection to 
unlicensed in-State residents consistent with Federal, State, and local 
law. There are also no recordkeeping requirements imposed by the GCA or 
the proposed or final rule upon unlicensed persons who make their own 
firearms, but only upon licensees who choose to take PMFs into 
inventory. In sum, this rule does not impose any new requirements on 
law-abiding gun owners.
---------------------------------------------------------------------------

    \63\ See Public Law 90-351, sec. 901(a)(1), 82 Stat. 225.
---------------------------------------------------------------------------

5. Suggested Changes to the Text
    Some commenters in support of the rule offered several suggestions 
on the text of the final rule while others asked that ATF take certain 
information into consideration. Notably, the combined comment submitted 
by 22 State Attorneys General in support of the proposed definitions 
offered seven suggestions for the final rule. The commenters' 
suggestions are addressed in the following paragraphs.
a. Definition of ``Firearm'' and Weapon Parts Kits
Comments Received
    Some commenters urged ATF to clarify the relationship between a 
weapon parts kit and a partially complete frame or receiver. Although 
the proposed rule includes a ``weapon parts kit'' within the definition 
of ``firearm'' and separately defines a ``partially complete, 
disassembled, or inoperable frame or receiver,'' the commenters stated 
that a partially complete frame is often sold as part of a weapon parts 
kit. Therefore, the commenters suggested that ATF clarify whether a 
parts kit must include a partially complete frame or receiver in order 
to satisfy the definition of ``firearm.''
    Other commenters asked ATF to consider how to effectively regulate 
the domestic distribution of Computer Aided Manufacturing (``CAM'') and 
Computer Aided Design (``CAD'') files and other software and technology 
used to produce firearms. They explained that these types of files are 
just like weapon parts kits and can be used to ``readily'' assemble a 
working firearm. The commenters stated that the Department of Commerce 
currently regulates only the international distribution and export of 
CAM or CAD files for the production of firearms where such files are 
``ready for insertion into a computer numerically controlled machine 
tool, additive manufacturing equipment, or any other equipment that 
makes use of'' the files ``to produce the firearm frame or receiver or 
complete firearm.'' 15 CFR 734.7(c). They suggested that there are 
opportunities for ATF to work alone or with other Departments, such as 
Commerce, to address the lack of regulation of the domestic 
distribution of CAM and CAD files and other software and technology 
used to produce firearms.
Department Response
    The Department agrees with commenters that the NPRM supplement 
entitled ``Partially Complete, Disassembled, or Inoperable Frame or 
Receiver'' should make clear that it includes a ``frame or receiver 
parts kit'' with a partially complete, disassembled, or nonfunctional 
(replacing ``inoperable'' in the final rule to describe the item more 
accurately) \64\ frame or receiver. The final rule incorporates that 
addition. However, a weapon parts kit need not have a partially 
complete frame or receiver, as defined in this rule, to satisfy the 
definition of ``firearm'' under section 921(a)(3)(A).\65\ For example, 
a weapon parts kit that contains pieces of a multi-piece frame or 
receiver, as defined in this rule, may still meet the definition of 
``firearm'' under section 921(a)(3)(A) if the kit ``is designed to or 
may readily be completed, assembled, restored, or otherwise converted 
to expel a projectile by the action of an explosive.''
---------------------------------------------------------------------------

    \64\ See footnote 122, infra.
    \65\ The existence of a frame or receiver is not a precondition 
to classifying a weapon as a firearm under section 921(a)(3)(A), as 
section 921(a)(3) defines a ``firearm'' in the disjunctive with each 
subpart separated by the disjunctive participle ``or.'' See Black's 
Law Dictionary 1095 (6th ed.1990) (defining the term ``or'' to mean 
``[a] disjunctive participle used to express an alternative or to 
give a choice of one among two or more things''); Antonin Scalia & 
Bryan A. Garner, Reading Law: The Interpretation of Legal Texts sec. 
12, at 116 (2012) (``Under the conjunctive/disjunctive canon, and 
combines items while or creates alternatives . . . . With a 
conjunctive list, all . . . things are required--while with the 
disjunctive list, at least one of the [things] is required, but any 
one . . . satisfies the requirement.''). Thus, while the term 
``firearm'' in section 921(a)(3)(B) includes the frame or receiver 
of a weapon described in section 921(a)(3)(A), section 921(a)(3)(A) 
does not require a weapon to have a ``frame or receiver,'' as each 
subpart qualifies, on its own, as a ``firearm'' for purposes of the 
GCA. Otherwise, section 921(a)(3)(A) would be superfluous.
---------------------------------------------------------------------------

    Regarding computer files, this rule as proposed and finalized does 
not regulate the domestic distribution of CAM or CAD computer files. 
This rule implements the GCA, which does not regulate the information 
used to manufacture firearms. However, it would violate federal law to 
aid and abet (18 U.S.C. 2) or conspire (18 U.S.C. 371) with others to 
manufacture firearms without a license (18 U.S.C. 922(a)(1)), which 
could include someone providing specially designed computer 
instructions for machines, such as Computer Numeric Control (CNC) 
machines or 3D printers, knowing that the purchaser is engaged in the 
business of producing firearms for sale or distribution without a 
license.
b. General Definition of ``Frame or Receiver''
Comments Received
    Some commenters in support of the proposed rule were concerned with 
the language ``when the complete weapon is assembled'' in the general 
definition of ``frame or receiver,'' which was proposed to be defined, 
in part, as a ``part of a firearm that, when the complete weapon is 
assembled, is visible from the exterior and provides housing or a 
structure designed to hold one or more fire control components'' 
(emphasis added). The commenters stated that the italicized language 
makes the definition susceptible to being read to say that the part of 
a weapon that is the ``frame or receiver'' only becomes so when the 
complete weapon is assembled. To avoid that possible misreading, the 
commenters suggested the sentence should indicate it is a part of a 
complete weapon that is visible from the exterior when the complete 
weapon is assembled and provides housing designed to hold or integrate 
one or more fire control components.
    Additionally, commenters also suggested the proposed definition of 
``frame or receiver,'' which refers to ``[a] part of a firearm,'' be 
changed to ``[a] part of a complete weapon,'' given that under both the 
GCA and regulatory definition, a ``firearm'' could mean just the 
``frame or receiver'' of a weapon. Similarly, commenters suggested that 
``complete weapon'' also be used instead of ``firearm'' where ATF 
proposes to define ``fire control component'' as ``a component 
necessary for the firearm to initiate, complete, or continue the firing 
sequence.'' They suggested using ``complete weapon'' in other instances 
where the supplemental definition, like split or modular frame or 
receiver, uses the term ``firearm'' in the definition.
Department Response
    The Department agrees that the phrase ``when the complete weapon is 
assembled, is visible'' in the proposed definition of ``frame or 
receiver'' could be misinterpreted to mean that the weapon or device 
must be assembled for a part to be defined as a frame or receiver. For 
this reason, and because

[[Page 24671]]

the definition of ``conspicuous'' in the marking requirements makes 
clear that markings must be capable of being easily seen with the naked 
eye during normal handling of the firearm and unobstructed by other 
markings when the complete weapon or complete muffler or silencer 
device is assembled (i.e., visible),\66\ the phrase ``when the complete 
weapon is assembled, is visible'' has been removed from the definition 
of ``frame or receiver'' in the final rule because it is unnecessary. 
Regarding the suggestion to substitute ``complete weapon'' for 
``firearm,'' the Department does not believe that change is necessary 
because the final rule now makes clear the terms under ``frame or 
receiver'' will be defined in relation to the type of weapon, not to 
``firearms'' generally.
---------------------------------------------------------------------------

    \66\ Markings must also be clearly visible from the exterior 
because they may be needed to prove that a criminal defendant had 
knowledge that the serial number was obliterated or altered. See, 
e.g., Lewis v. United States, No. 3:12-0522, 2012 WL 5198090, at *4 
(M.D. Tenn. Oct. 19, 2012) (serial number obliterated on the 
``visible exterior'' of a revolver); State v. Shirley, No. 107449, 
2019 WL 2156402, at *2 (Ct. App. Ohio May 16, 2019) (same); cf. 
United States v. Sands, 948 F.3d 709, 719 (6th Cir. 2020) (serial 
number is not altered or obliterated so long as it is ``visible to 
the naked eye''); United States v. St. Hilaire, 960 F.3d 61, 66 (2d 
Cir. 2020) (``This `naked eye test' best comports with the ordinary 
meaning of `altered'; it is readily applied in the field and in the 
courtroom; it facilitates identification of a particular weapon; it 
makes more efficient the larger project of removing stolen guns from 
circulation; it operates against mutilation that impedes 
identification as well as mutilation that frustrates it; and it 
discourages the use of untraceable weapons without penalizing 
accidental damage or half-hearted efforts.'').
---------------------------------------------------------------------------

c. Supplement ``Split or Modular Frame or Receiver''
Comments Received
    Some commenters indicated that it appears an item may qualify under 
the supplement entitled ``split or modular frame or receiver'' only if 
the Director makes that determination based on certain factors. The 
commenters suggested that the definition would be enhanced if it also 
provided a standard that may be generally used to determine whether 
something is a ``split or modular frame or receiver,'' as well as 
additional factors that may inform how that standard is applied. In 
this way, the regulations would define ``a split or modular frame or 
receiver'' much as the proposed rule suggests defining ``readily.'' The 
commenters recommended inserting ``each of those parts shall be a frame 
or receiver unless'' before ``the Director may determine'' and then 
changing ``may determine'' to ``determines.'' Commenters also suggested 
making clear that the courts and the public, in addition to the 
Director, may rely on the identified factors to determine whether 
something is a ``partially complete, disassembled, or inoperable frame 
or receiver'' for that definition.
Department Response
    With respect to the definitional supplement ``split or modular 
frame or receiver,'' the Department disagrees that this provision as 
proposed was meant to be read as providing that a part may only qualify 
as a ``split or modular frame or receiver'' if the Director makes that 
determination based on the enumerated factors. This supplement was 
intended to inform the licensed industry and the public that if there 
is more than one part of a firearm falling within the proposed 
definition of ``frame or receiver'' (i.e., more than one housing or 
structure for a fire control component), then ATF would use those 
factors when determining which specific part(s) of a split or modular 
weapon or device was the frame or receiver of that weapon or device. As 
with past ATF classifications, there would likely be only one such 
component specified in future designs.
    In light of these and numerous other comments seeking more clarity 
as to how the definition of ``frame or receiver'' applies with respect 
to split and modular firearms, the Department is adopting three subsets 
of the proposed definition of ``frame or receiver''--one that applies 
to handguns; one for rifles, shotguns, and projectile weapons other 
than handguns; and one for firearm mufflers and silencers. The 
Department agrees with numerous commenters that the proposed supplement 
to the definition entitled ``split or modular frame or receiver'' is 
difficult for persons to apply when the term ``frame or receiver'' was 
defined to include more than any housing for any fire control 
component. Because the final rule focuses on only a single component of 
a firearm based on the recommendations of commenters, there is no 
longer a need for a separate supplement entitled ``split or modular 
frame or receiver'' and it has not been adopted in the final rule.
    However, while defining the term ``frame or receiver'' to focus on 
a single component and removing the supplement entitled ``split or 
modular frame or receiver'' provides clarity as to which part of a 
``split'' frame or receiver (i.e., with upper and lower housings for 
the bolt, breechblock, and trigger mechanism) is regulated, it does not 
provide clarity with respect to multi-piece frames or receivers that 
are designed to be disassembled into multiple modular subparts, more 
than one of which may house or provide a structure for the applicable 
fire control component specified in this rule (e.g., left and right 
halves of a frame or receiver). While these types of frames or 
receivers are relatively uncommon, ATF has seen an increase in multi-
piece designs of frames or receivers. To address these new designs, the 
term ``multi-piece frame or receiver'' has been added to the final rule 
to mean a frame or receiver that may be disassembled into multiple 
modular subparts. To avoid confusion between multi-piece receivers that 
may be disassembled into modular subparts, and modular handguns with an 
internal removable chassis like the Sig P250/320 and Beretta APX 
Striker,\67\ the definition expressly excludes the internal frame of a 
pistol that is a complete removable chassis that provides housing for 
the energized component, unless the chassis itself may be disassembled.
---------------------------------------------------------------------------

    \67\ An internal removable chassis system (as found in the Sig 
P250/320 and Beretta APX Striker) that houses all components of a 
traditional pistol frame, to include incorporating the slide rails 
and housing for both the trigger and sear/hammer, is a complete 
pistol frame without the polymer grip.
---------------------------------------------------------------------------

    This rule clarifies for licensees which portion of a modular multi-
piece frame or receiver they will need to identify with a serial number 
and additional identifying information. Pursuant to its authority under 
18 U.S.C. 923(i) and 26 U.S.C. 5842(a), ATF is prescribing in this rule 
the manner in which licensed manufacturers and importers (and makers of 
NFA firearms) must identify multi-piece frames or receivers, as 
follows: (1) The outermost housing or structure designed to house, 
hold, or contain either the primary energized component of a handgun, 
the breech blocking or sealing component of a projectile weapon other 
than a handgun, or the internal sound reduction component of a firearm 
muffler or firearm silencer, as the case may be, is the subpart of a 
multi-piece frame or receiver that must be marked with the identifying 
information; (2) if more than one modular subpart is similarly designed 
to house, hold, or contain such a primary component (e.g., left and 
right halves), each of those subparts must be identified with the same 
serial number and associated licensee information not duplicated on any 
other frame or receiver; and (3) the marked subpart(s) of a multi-piece 
frame or receiver must be presumed, absent an official determination by 
the Director or other reliable evidence to the contrary, to be part of 
the frame or receiver of a weapon.
    The final rule provides that, once a modular subpart of a multi-
piece frame

[[Page 24672]]

or receiver has been marked and then aggregated (assembled or 
unassembled) with the other frame or receiver subparts, the marked part 
cannot be removed and replaced unless: (1) The subpart replacement is 
not a firearm under 26 U.S.C. 5845; (2) the subpart replacement is 
identified by the licensed manufacturer of the original subpart with 
the same serial number and associated licensee information in the 
manner prescribed by the rule; and (3) the original subpart is 
destroyed under the firearm licensee's control or direct supervision 
prior to such placement. These conditions are necessary because 
removing and replacing the identified component of a multi-piece frame 
or receiver would place the possessor in violation of 18 U.S.C. 922(k) 
(and, if an NFA firearm, 26 U.S.C. 5861(g) and (h)), which prohibits 
the possession of any firearm with the manufacturer's or importer's 
serial number removed. If a modular subpart of a multi-piece frame or 
receiver is sold separately, the rule requires that it be identified 
with an individual serial number. This is to ensure that the frame or 
receiver of the resulting weapon has traceable marks of identification. 
These clarifications with respect to the markings of a multi-piece 
frame or receiver are necessary for the final rule; otherwise, multi-
piece frames or receivers could be sold or distributed piecemeal in 
individual subparts and replaced by the end user without any traceable 
marks of identification.
    Finally, to ensure that industry members and others can rely on 
ATF's prior classifications, most prior ATF classifications and 
variants thereof, including those for externally powered weapons, have 
been grandfathered into the definition of ``frame or receiver'' along 
with examples and diagrams of those weapons, such as AR-15/M-16 variant 
firearms. The only exception is for classifications that a partially 
complete, disassembled, or nonfunctional frame or receiver, including a 
parts kit, was not, or did not include, a firearm ``frame or receiver'' 
as defined prior to this rule. Any such classifications, to include 
weapon or frame or receiver parts kits, would need to be resubmitted 
for evaluation. Further, if persons remain unclear as to which specific 
portion of a weapon or device falls within the definition of ``frame or 
receiver,'' then they may still voluntarily submit a request to ATF as 
otherwise provided in this rule.
d. Definition of ``Privately Made Firearm''
Comments Received
    Some commenters suggested that ATF should explain that ``made,'' as 
used in the definition of ``privately made firearm,'' does not imply 
that firearms cannot be ``manufactured'' by private parties for 
purposes of other firearms laws. They stated that the proposed rule 
opted for ``privately made firearm'' instead of ``privately 
manufactured firearms'' to distinguish between what an FFL does 
(manufacture) and what a nonlicensee does (make). These commenters 
asserted that the NFA's definition of ``make'' demonstrates that the 
distinction between ``make'' and ``manufacture'' is not consistent 
throughout Federal law. Therefore, the commenters requested that ATF 
should clarify that its use of ``made'' in this regulation does not 
limit the meaning of either ``made'' or ``manufacture'' as used in this 
and other Federal laws and regulations.
Department Response
    The Department agrees that the term ``made'' in the definition of 
``privately made firearm'' was not meant to restrict the use of the 
terms ``made'' or ``manufacture'' with respect to the GCA or other 
firearms laws. As the preamble in the NPRM explained, the term ``made'' 
was incorporated into that definition merely to distinguish those 
firearms that were manufactured by licensees from those manufactured by 
unlicensed persons. See 26 U.S.C. 5845(i) (``The term `make', and the 
various derivatives of such word, shall include manufacturing (other 
than by one qualified to engage in such business under this chapter), 
putting together, altering, any combination of these, or otherwise 
producing a firearm.''). This rule is not intended to limit the meaning 
of ``made'' or ``manufacture'' in the GCA or any other Federal law, or 
with respect to State or local firearms laws.\68\
---------------------------------------------------------------------------

    \68\ See 18 U.S.C. 927 (GCA does not preempt State or local law 
unless there is a direct and positive conflict with Federal law such 
that they cannot be reconciled or consistently stand together).
---------------------------------------------------------------------------

e. Marking of ``Privately Made Firearms''
Comments Received
    Some supportive commenters suggested that the final rule should 
clarify that any identifying marks must be placed on the metal insert 
of an otherwise undetectable PMF, not on any polymer or other nonmetal 
part or component, to ensure the marks are not worn away during normal 
use. The commenters believed this is what the preamble suggested, 
although the text of the proposed regulations did not do so explicitly.
    The California Department of Justice stated that ATF should 
consider extending the PMF serialization requirement to owners as well 
as firearms licensees so as to foreclose the possibility that any PMFs 
will remain untraceable. This commenter stated that ATF could require 
owners of PMFs to register those weapons after a reasonable time frame, 
such as 60 days after the effective date of the regulation, which would 
ensure all PMFs are safely tracked by law enforcement.
Department Response
    The Department agrees that the final rule should make clear that 
one of the acceptable methods of marking a PMF, or a commercially 
produced firearm, is to permanently embed a serialized metal plate into 
polymer or other nonmetal material. The final rule adds this as an 
acceptable example in addition to recognizing any other method approved 
by the Director. This can be accomplished by casting, molding, or 
another manufacturing method, such as 3D overprinting.\69\
---------------------------------------------------------------------------

    \69\ See generally Hayley Everett, Lehvoss Group Leads Innovate 
UK Project for Overprinting High-Performance 
Polymers,3DPrintingIndustry.com (Aug. 25, 2021), available at 
https://3dprintingindustry.com/news/lehvoss-group-leads-innovate-uk-project-for-overprinting-high-performance-polymers-195071/ (last 
visited Mar. 23, 2022) (``Overprinting is a technique for designing 
multi-material parts when different materials are needed in various 
components of a part. Typically, a print is started and then paused 
midway whereby components can be embedded into the 3D print job. 
Then, the print process is resumed and allowed to 3D print over the 
components that have been embedded.''); MMF #5: A Guide to Embedding 
Components in 3D Printed Parts, Markforged.com, available at https://markforged.com/resources/blog/embedding-components-in-3d-printed-parts (last visited Mar. 23, 2022); How to Insert Internal 
Components with Markforged Composite 3D Printing, Hawkridgesys.com 
(June 9, 2020), available at https://hawkridgesys.com/blog/how-to-insert-internal-components-with-markforged-composite-3d-printing 
(last visited Mar. 23, 2022).
---------------------------------------------------------------------------

    The Department, however, disagrees that serialization should be 
limited to a particular method. The current regulations and this rule 
already require that identification marks be placed in a manner not 
susceptible of being readily obliterated, altered, or removed. While 
the commenters raised the point that the serial number with the Federal 
firearms licensee's abbreviated license number prefix would normally be 
placed on a metal insert to meet this requirement, the Department 
believes that other permanent methods and hardened materials for 
marking may be developed in the future as technology progresses.

[[Page 24673]]

Additionally, the GCA, 18 U.S.C. 922(p), only requires that firearms be 
as detectable as the ``Security Exemplar'' that contains 3.7 ounces of 
material type 17-4 PH stainless steel. This detectable material is 
likely to be metal, but it could be another substance. So long as the 
identification marks cannot readily be removed, obliterated, or 
altered, no additional marking requirement is necessary.\70\ However, 
if the serial number or other markings may readily be removed, 
obliterated, or altered when placed using a particular method or 
material, then the licensee cannot adopt that serialization process to 
meet the identification requirements.
---------------------------------------------------------------------------

    \70\ See 26 U.S.C. 5842(a) (serial number ``may not be readily 
removed, obliterated, or altered'').
---------------------------------------------------------------------------

    In response to the comment that the rule should extend the 
serialization requirement for PMFs to individual owners, unlike the 
NFA, the GCA does not impose a marking or recordkeeping requirement on 
unlicensed persons who are not engaged in a business or activity 
requiring a license. Nonetheless, under the GCA, 18 U.S.C. 927, State 
and local jurisdictions are free to enact their own requirements and 
restrictions on PMFs provided they do not directly and positively 
conflict with Federal law.
f. Marking of a ``Firearm Muffler or Silencer''
Comments Received
    At least one commenter welcomed the change under which silencers 
would only need to be marked on the designated frame or receiver of a 
silencer, and that minor components of silencers would not need to be 
engraved or registered when transferred between Special Occupation 
Taxpayers (``SOTs'') for repair. This provision, the commenter stated 
approvingly, conforms policy to longstanding practice.
Department Response
    The Department acknowledges commenters' support for the proposal 
not to require firearm mufflers or silencer parts other than the frame 
or receiver of a silencer to be marked or registered when transferred 
between qualified SOTs for repair. This rule finalizes that proposal 
with minor clarifying changes. The Department notes that this change 
would not adversely impact public safety because the frame or receiver 
of the complete firearm muffler or silencer devices being repaired are 
registered in the NFRTR and recorded as a disposition whenever an 
actual device is transferred.
g. Firearms Designed and Configured Before Effective Date of Rule
Comments Received
    The group Everytown for Gun Safety Support Fund stated that ATF 
needs to make clear that its prior classifications of ``nearly-
complete'' frames and receivers are no longer valid, as some sellers of 
these items display these classification letters on their websites to 
promote their products. The commenter said that this clarification was 
necessary to ensure these sellers do not continue to exploit outdated 
letters as legal cover for selling firearms illegally.
Department Response
    The Department agrees with this comment. Certain prior ATF 
classifications of a ``partially complete, disassembled, or 
nonfunctional frame or receiver'' will not be grandfathered upon 
issuance of this final rule. In the past, ATF encountered situations in 
which incomplete frames or receivers were sent to ATF for 
classification without any of the other parts, jigs, templates, or 
materials that are sold or distributed with the item or kit. ATF then 
issued a classification that an unfinished item or kit was not a 
``frame or receiver'' without the benefit of, or considering, such 
parts, jigs, templates, or information. In addition to not 
grandfathering these particular classifications, this rule finalizes 
the proposed process that any person seeking a voluntary classification 
must submit any associated templates, jigs, molds, equipment, or tools 
that are made available by the seller or distributor of the item or 
kit, to the purchaser or recipient of the item or kit, and any 
instructions, guides, or marketing materials if they will be made 
available by the seller or distributor with the item or kit. This is to 
ensure that a proper classification can be made under the new 
definitions. ATF will reconsider those firearm classifications, and any 
prior classifications of such items or parts kits would need to be 
resubmitted if a requester wants a voluntary determination.
h. Recordkeeping Requirements
Comments Received
    The City of Oakland, California, which expressed support for the 
proposed rule, stated that their support is based on the NPRM taking 
into account the racially inequitable impacts of gun violence and over-
policing. The City had several suggestions for the final rule to better 
account for the potential racial collateral consequences of the 
proposed rule and help Black and Brown communities disproportionately 
harmed by gun violence to respond to PMFs already in their community. 
These suggestions included the following: (1) ATF should collect, 
retain, and study the information collected through the ATF Form 4473, 
which they stated should include demographic information; (2) ATF 
should provide clear guidance for local law enforcement on how to 
collect data on ``ghost guns,'' including data that can be 
disaggregated by race, and ensure that implementing the rule does not 
lead to over-policing of Black and Brown communities; (3) ATF should 
work with the Executive Office for U.S. Attorneys and other Department 
partners on how to ensure that Black and Brown persons are not 
disproportionately charged with firearms-related offenses in Federal 
prosecutions; (4) ATF should include an explicit non-discrimination 
clause with respect to enforcement of the rule; (5) ATF should include 
model programs and best practices for how communities can respond to 
and mitigate the harm posed by ghost guns and gun violence, like 
Oakland Ceasefire; and (6) ATF should develop guidance for 
manufacturers and sellers to inform them of ATF's enforcement 
priorities.
Department Response
    The Department acknowledges the commenter's support for the 
proposed rule; however, ATF cannot ``collect, retain, and study'' 
information on the ATF Forms 4473 for the purpose of evaluating 
potential racial collateral consequences of this rule. First, ATF does 
not retain the ATF Forms 4473, as they are owned and maintained by FFLs 
while they are in business. Therefore, the demographic and other 
information included on those forms is located throughout the country 
in the individual business records of FFLs. Second, the demographic 
information on that form (race and ethnicity) may only be used for 
limited purposes--collecting information required for the FFL to run a 
National Instant Criminal Background Check System (``NICS'') background 
check,\71\ and for certain law enforcement purposes, such as correctly

[[Page 24674]]

identifying the original purchaser of a firearm later used in a violent 
crime.\72\ Although this demographic information is used for background 
check purposes, it is not maintained by the NICS. The NICS, which is 
administered by the FBI, is required by law to destroy all identifying 
information on prospective purchasers within 24 hours of providing a 
response that the transfer may proceed.\73\ ATF may also inspect 
individual ATF Forms 4473 containing personally identifiable 
information held by FFLs, but only for limited regulatory or law 
enforcement functions--specifically, during inspections, and in the 
course of investigations, such as when tracing firearms linked to 
individual criminal investigations. Finally, statutory and 
appropriations restrictions prohibit ATF from promulgating any rule 
requiring the maintenance of a database or other information repository 
of the race or ethnicity of firearm purchasers or licensees.\74\ For 
these reasons, the Department cannot require the systematic collection 
of such demographic information for statistical, programmatic, or other 
purposes as part of this rule.
---------------------------------------------------------------------------

    \71\ After passage of the Brady Handgun Violence Prevention Act 
in 1993 (see 18 U.S.C. 922(t)), the FBI promulgated regulations to 
implement the NICS. These regulations, see 28 CFR 25.7, prescribe 
the search criteria used by NICS and state: ``[T]he following search 
descriptors will be required in all queries of the system for 
purposes of a background check: (1) Name; (2) Sex; (3) Race; (4) 
Complete date of birth; and (5) State of residence'' (emphasis 
added). This information is needed to facilitate proper 
identification by providing additional information that helps 
match--or rule out a match--between an individual and a potentially 
prohibiting record.
    \72\ There are some limited circumstances under which the ATF 
Forms 4473 or information contained thereon is reported to ATF, for 
example, as part of the statutorily authorized demand letter 
program, pursuant to 18 U.S.C. 923(g)(5). Those circumstances are 
exceptions to the general rule, and even under those circumstances, 
ATF does not aggregate or centralize the demographic information 
contained on those forms.
    \73\ Public Law 112-55, sec. 511, 125 Stat. 632 (2011); 28 CFR 
25.9.
    \74\ See 18 U.S.C. 926 (``No rule or regulation . . . may 
require that records required to be maintained under this chapter or 
any portion of the contents of such records, be recorded at or 
transferred to a facility owned, managed, or controlled by the 
United States or any State or any political subdivision thereof, nor 
any system of registration of firearms, firearms owners, or firearms 
transactions or dispositions be established.''); Public Law 103-159, 
sec. 103(i), 107 Stat. 1536 (1993) (``No department, agency, 
officer, or employee of the United States may--(1) require that any 
record or portion thereof generated by the [NICS] system established 
under this section be recorded at or transferred to a facility 
owned, managed, or controlled by the United States or any State or 
political subdivision thereof . . . .''). Additionally, since 1979, 
congressional appropriations have prohibited ATF from using any 
funds or salaries in connection with the consolidation or 
centralization of records of acquisition and disposition of firearms 
maintained by FFLs. See Treasury, Postal Service, and General 
Government Appropriations Act, 1980, Public Law 96-74, 93 Stat. 560 
(1979). This annual restriction became permanent in 2011. See Public 
Law 112-55, 125 Stat. 632 (2011).
---------------------------------------------------------------------------

    Commenter's remaining suggestions regarding racial equality are 
beyond the scope of this rule.\75\ This rule implements the GCA, which 
was passed, in part, to help Federal, State, and local law enforcement 
prevent illicit firearms trafficking within their respective 
jurisdictions.\76\ Specifically, this rule is intended, in part, to 
address the proliferation of unserialized ``ghost guns,'' which are 
increasingly being recovered at crime scenes, and law enforcement's 
difficulty in tracing them when recovered. The rule accomplishes this 
objective by clarifying the serialization and recordkeeping 
requirements that preserve ATF's ability to trace firearms for Federal, 
State, local, and international law enforcement wherever firearm 
violence may occur.
---------------------------------------------------------------------------

    \75\ As a general matter, the Department's prosecutorial 
practices and priorities are set forth in the ``Principles of 
Federal Prosecution'' in the DOJ Justice Manual Sec. Sec.  9-27.000, 
et seq. Section 9-27.260 (``Initiating and Declining Charges--
Impermissible Considerations'') reads, in pertinent part, ``In 
determining whether to commence or recommend prosecution or take 
other action against a person, the attorney for the government 
should not be influenced by . . . [t]he person's race, religion, 
gender, ethnicity, national origin, sexual orientation, or political 
association, activities, or beliefs.''
    \76\ See Public Law 90-351, sec. 901(a), 82 Stat. 225-26.
---------------------------------------------------------------------------

B. Issues Raised in Opposition to the Rule

    Thousands of commenters broadly expressed opposition to the NPRM 
with numerous form letters submitted. Over 7,000 commenters simply 
opposed without providing concrete reasons while the majority raised 
specified concerns about the proposed rule. ATF received comments from 
a variety of interested parties, including from FFL retailers and 
manufacturers, organizations, various lawmakers, knowledgeable gun 
enthusiasts, and persons with law enforcement backgrounds. As discussed 
below, numerous other commenters raised various concerns about the 
Department's proposed amendments to ATF regulations. These reasons 
included constitutional and statutory authority concerns, issues with 
the clarity and effect of the proposed definitions and changes to 
recordkeeping and marking requirements, and concerns about the public 
safety goals of the Department in promulgating this rule.
1. Constitutional Concerns
a. Violates the Ex Post Facto Clause
Comments Received
    Several hundred commenters opposed to the rule stated that it 
directly violates Clause 3 of Article I, Section 9, of the United 
States Constitution, which prohibits ``ex post facto Law[s].'' These 
commenters' opposition comes from their belief that, once the proposed 
rule goes into effect, possession of items that are currently lawful 
would be no longer legal, and that the new prohibition would constitute 
an ex post facto law.
Department Response
    The Department disagrees that the proposed rule violates the Ex 
Post Facto Clause. In Calder v. Bull, 3 U.S. (3 Dall.) 386 (1798), the 
Supreme Court set out four types of laws that violate the Ex Post Facto 
Clause:

    1st. Every law that makes an action, done before the passing of 
the law, and which was innocent when done, criminal; and punishes 
such action. 2nd. Every law that aggravates a crime, or makes it 
greater than it was, when committed. 3rd. Every law that changes the 
punishment, and inflicts a greater punishment, than the law annexed 
to the crime, when committed. 4th. Every law that alters the legal 
rules of evidence, and receives less, or different, testimony, than 
the law required at the time of the commission of the offence, in 
order to convict the offender.

Id. at 390. Citing Calder, the Supreme Court has explained that a ``law 
must be retrospective--that is, it must apply to events occurring 
before its enactment--and it must disadvantage the offender affected by 
it by altering the definition of criminal conduct or increasing the 
punishment for the crime'' to be considered as falling within the ex 
post facto prohibition. Lynce v. Mathis, 519 U.S. 433, 441 (1997) 
(citation and internal quotation marks omitted). Courts have 
consistently recognized that regulating the continued or future 
possession of a firearm that is already possessed does not implicate 
the Ex Post Facto Clause because such a regulation does not criminalize 
past conduct. See, e.g., United States v. Pfeifer, 371 F.3d 430, 436-37 
(8th Cir. 2004); United States v. Mitchell, 209 F.3d 319, 322 (4th Cir. 
2000); United States v. Brady, 26 F.3d 282, 290-91 (2d Cir. 1994); 
United States v. Gillies, 851 F.2d 492, 495-96 (1st Cir. 1988) (Breyer, 
J.); United States v. D'Angelo, 819 F.2d 1062, 1065-66 (11th Cir. 
1987); see also Samuels v. McCurdy, 267 U.S. 188, 193 (1925) (rejecting 
Ex Post Facto Clause challenge to statute that prohibited the post-
enactment possession of intoxicating liquor, even when the liquor was 
lawfully acquired before the statute's enactment).
    Here, penalties would result only from the future failure to mark 
firearms. For FFLs that already have unmarked firearms kits, frames, or 
receivers, they have 60 days from the effective date of the rule to 
appropriately mark these firearms. See 27 CFR 478.92(a)(4)(vi). 
Moreover, as this rule in other respects simply describes the proper 
application

[[Page 24675]]

of the terms Congress used in various provisions of the GCA, it does 
not impose liability independent of the preexisting requirements of 
those statutes. For these reasons, the Department disagrees with 
commenters' assertions that the rule violates the Ex Post Facto Clause.
b. Violates the First Amendment
Comments Received
    A few commenters raised concerns that the proposed definitions 
violate the First Amendment. One commenter, an organization of artisans 
who create artistic arrangements that use ``arbitrary components, some 
of which are semi-processed firearm components such as barrels [and] 
pistol slides,'' is concerned that if artisans are required to check 
with ATF on its opinion when using novel or arbitrary components in 
their artwork, this requirement would be a prior restraint on protected 
expression. The commenting organization stated that ATF's definitions 
are so vague that it does not know what ATF would consider novel 
``modular'' designs that might be considered a frame or receiver. 
Further, the organization claimed that under the nonexclusive lists in 
the proposed definition just about any major gun part could check more 
than one box on ATF's ``unlimited features'' and be considered a frame 
or receiver. As such, the organization argued that the vague, open-
ended definitions in the NPRM ``would chill an artisan--one with a 
specific desire not to use any gun part which could be considered a 
`firearm' and thus require the employ of an FFL--from engaging in First 
Amendment protected expression.'' Other commenters stated that the NPRM 
also raises First Amendment concerns because the Director would be able 
to determine when a component has become a firearm based on a company's 
instructions and how a company markets the product.
Department Response
    The Department agrees with the commenters who asserted that the 
proposed definition was potentially confusing, but disagrees with the 
commenters' First Amendment objections. First, the Department 
recognizes that the definition as proposed would have made it more 
difficult for artisans and others to determine whether they would be 
acquiring a ``frame or receiver'' subject to regulation. For this 
reason, and because the Department agrees with commenters that the 
definition of ``firearm'' in 18 U.S.C. 921(a)(3)(B) is best read to 
mean that a single part of a weapon or device is the frame or receiver, 
this rule adopts subsets of the proposed definition of ``frame or 
receiver'' to define ``frame'' and ``receiver'' so that licensees and 
the public can make this determination without an ATF classification. 
The Department has accordingly established new distinct definitions for 
frames with respect to handguns; receivers with respect to rifles, 
shotguns, and projectile weapons other than handguns; and frames or 
receivers for firearm mufflers or silencers.
    The Department, however, does not agree with commenters that the 
rule would violate the First Amendment rights of artisans. The Supreme 
Court has held the First Amendment is not implicated by the enforcement 
of a regulation of general application not targeted at expressive 
activity. See Arcara v. Cloud Books, Inc., 478 U.S. 697, 707 (1986) 
(upholding closure sanction of ``an establishment used for 
prostitution'' where respondents also ``happen to sell books''). First 
Amendment scrutiny ``has no relevance to a statute directed at . . . 
non-expressive activity,'' and applies ``only where it was conduct with 
a significant expressive element that drew the legal remedy in the 
first place.'' Id. at 706-707; see also Wright v. City of St. 
Petersburg, Florida, 833 F.3d 1291, 1298 (11th Cir. 2016) (``First 
Amendment scrutiny ha[d] no relevance to [a trespass ordinance] 
directed at imposing sanctions on nonexpressive activity.'' (internal 
quotation marks omitted)); Talk of the Town v. Department of Finance & 
Business Servs ex rel. Las Vegas, 343 F.3d 1063, 1069 (9th Cir. 2003) 
(section of Las Vegas Code barring consumption of alcohol in places 
that lack valid liquor license--including exotic dancing 
establishments--``in no way can be said to regulate conduct containing 
an element of protected expression''). The definitions at issue are not 
targeting expressive conduct of any kind but are part of a ``regulation 
of general application'' clarifying the definition of frame and 
receiver and the marking requirements thereof. As such, the 
Department's position is that the First Amendment is not implicated by 
this rule.
    However, in an abundance of caution and because artwork in general 
is expressive conduct entitled to First Amendment protection, see Texas 
v. Johnson, 491 U.S. 397, 404 (1989), and assuming this regulation 
somehow affects that conduct, the definitions still do not target 
expressive conduct and strict scrutiny review is not appropriate under 
the First Amendment analysis set out in United States v. O'Brien, 391 
U.S. 367 (1968). ``[W]hen `speech' and `nonspeech' elements are 
combined in the same course of conduct, a sufficiently important 
governmental interest in regulating the nonspeech element can justify 
incidental limitations on First Amendment freedoms.'' Id. at 376. Under 
an O'Brien analysis--

    a government regulation is sufficiently justified [1] if it is 
within the constitutional power of the Government; [2] if it 
furthers an important or substantial governmental interest; [3] if 
the governmental interest is unrelated to the suppression of free 
expression; and [4] if the incidental restriction on alleged First 
Amendment freedoms is no greater than is essential to the 
furtherance of that interest.

Id. at 377.
    First, ``the Government may constitutionally regulate the sale and 
possession of firearms.'' Wilson v. Lynch, 835 F.3d 1083, 1096 (9th 
Cir. 2016). Second, courts have repeatedly held that public safety and 
the prevention of crime are not only substantial, but compelling 
governmental interests. See United States v. Salerno, 481 U.S. 739, 750 
(1987); Mai v. United States, 952 F.3d 1106, 1116 (9th Cir. 2020); 
Worman v. Healey, 922 F.3d 26, 39 (1st Cir. 2019); New York State Rifle 
& Pistol Ass'n v. Cuomo, 804 F.3d 242, 261 (2d Cir. 2015); Kolbe v. 
Hogan, 849 F.3d 114, 139 (4th Cir. 2017); Horsley v. Trame, 808 F.3d 
1126, 1132 (7th Cir. 2015). Third, ``the Government's efforts to reduce 
gun violence'' are not directed at any expressive conduct and cannot be 
construed to be related to the suppression of free expression in any 
way. Wilson, 835 F.3d at 1096-97. Fourth, the definitions do not ban 
the private making of a firearm nor the unregulated possession of non-
frame or non-receiver firearms parts. Nor do the definitions ban the 
possession of a frame or receiver, but only require that a frame or 
receiver be marked; therefore, any burden is ``incidental'' and 
``minimal.'' Id. Because the regulation ``satisfies each of the O'Brien 
conditions, it survives intermediate scrutiny.'' Id. at 1097 (finding 
ATF's Open Letter to Federal Firearms Licensees informing them that the 
presentment of a purported purchaser's medical marijuana registry card 
would give them cause to deny the sale as violating 18 U.S.C. 922(d)(3) 
did not violate the First Amendment even if having the card was 
considered expression). Therefore, even if the O'Brien standard 
applies, the definitions do not violate the First Amendment. See 
Arcara, 478 U.S. at 707 (``O'Brien . . .

[[Page 24676]]

has no relevance [to a rule regulating] nonexpressive activity'').
c. Violates the Second Amendment
Comments Received
    A majority of commenters opposed to the NPRM objected to it on 
grounds that any changes to the definitions or the creation of new 
requirements that undermine the Second Amendment are unconstitutional, 
stating that the right to build firearms dates back to the founding of 
the Republic and that requiring markings on PMFs is an unconstitutional 
infringement of their Second Amendment rights. Commenters stated that 
ATF has encouraged hobbyists to fabricate firearms for their personal 
use and that the new requirements will restrain them from exercising 
their constitutional rights. Others objected saying that the NPRM 
failed to include relevant Second Amendment analysis. One commenter 
provided its own analysis, claiming that since District of Columbia v. 
Heller, 554 U.S. 570 (2008), a majority of gun control laws are 
examined under a reasonableness standard, which requires the regulation 
be a reasonable method for achieving the objectives of the regulation. 
Commenters claimed that ATF's proposed regulations would fail to meet 
the reasonableness standard because the evidence the agency cites 
actually proves that unfinished lower receivers are not even a marginal 
contributor to America's gun violence problem. Under their 
calculations, the commenters estimate that PMFs have been used only 
.837 percent of the time in deaths resulting from gun violence. 
Commenters concluded the proposed regulations are not a reasonable 
method to achieve the goal of reducing gun violence and therefore do 
not pass constitutional muster since the data does not demonstrate that 
regulating unfinished lower receivers will result in a statistically 
significant reduction of deaths from firearms.
Department Response
    The Department disagrees with commenters that the new requirements 
are unconstitutional under the Second Amendment. First, the GCA and 
this rule do not prohibit individuals from assembling or otherwise 
making their own firearms from parts for personal use, such as self-
defense or other lawful purposes. Neither the GCA nor this rule 
prohibits law-abiding citizens from completing, assembling, or 
transferring firearms without a license as long as those persons are 
not engaged in the business of manufacturing or importing firearms for 
sale or distribution, or dealing in firearms, or transacting curio or 
relic firearms in a manner requiring a license. See 18 U.S.C. 
922(a)(1), 923(a)-(b).
    Second, this final rule is consistent with the Supreme Court's 
decision in District of Columbia v. Heller, 554 U.S. 570 (2008). There 
are compelling governmental interests in requiring privately made 
firearms to be marked and recorded whenever they are accepted into the 
business or collection inventories of licensees. The Supreme Court 
recognized in Heller, 554 U.S. at 626-27 & n.26, that ``presumptively 
lawful regulatory measures'' include those ``imposing conditions and 
qualifications on the commercial sale of arms.'' PMFs, like 
commercially produced firearms, must be able to be traced through the 
records of licensees when the PMFs are involved in crimes. PMFs cannot 
be traced through a licensee's records without the manufacturers' 
serial numbers placed on PMFs by licensees, as required by this rule. 
Cf. United States v. Marzzarella, 614 F.3d 85, 99 (3d Cir. 2010) 
(concluding that even if strict scrutiny were to apply, 18 U.S.C. 
922(k) (prohibiting possession of firearms with obliterated serial 
numbers) would be upheld under the Second Amendment because ``serial 
number tracing serves a governmental interest in enabling law 
enforcement to gather vital information from recovered firearms,'' and 
``[b]ecause it assists law enforcement in this manner, we find its 
preservation is not only a substantial but a compelling interest'').
    Commenters also suggested that a licensing requirement for the 
manufacture of firearms violates the Second Amendment. Preexisting law 
requires those engaged in the business of manufacturing, importing, or 
dealing firearms to be licensed. That requirement does not burden the 
ability of non-prohibited people to buy, sell, or possess firearms, and 
no court has opined that the Second Amendment protects the right to 
engage in the business of unlicensed manufacturing. Heller ``did not 
touch in any way on an individual's right to manufacture or create 
those arms.'' Defense Distributed v. United States Dep't of State, 121 
F. Supp. 3d 680, 699 (W.D. Tex. 2015) (finding prepublication approval 
for software data files, project files, coding, and model for producing 
3D printed firearms was a burden that fell ``well short of that 
generally at issue in Second Amendment cases''). As stated above, the 
regulation does not ban the private making of a firearm.\77\ See id. 
(plaintiffs ``are not prohibited from manufacturing their own firearms, 
nor are they prohibited from keeping and bearing other firearms'').
---------------------------------------------------------------------------

    \77\ There is no historical support for the idea that private 
individuals regularly and easily manufactured firearms at home at 
the time of the Founding. ``[F]irearms were not like apple pies, 
which a typical family could make at home . . . . [T]hey were items 
of commerce that were nearly impossible to produce without 
specialized equipment and skill.'' David B. Kopel, Does the Second 
Amendment Protect Commerce?, 127 Harv L. Rev. Forum 230, 237 (Apr. 
11, 2014).
---------------------------------------------------------------------------

    In rejecting a Second Amendment challenge to the analogous 
requirement to be licensed as a dealer in firearms, the Fourth Circuit 
found the licensing requirement ``covers only the commercial sale of 
firearms. It affects only those who regularly sell firearms . . . . It 
explicitly excludes the vast majority of noncommercial sales.'' United 
States v. Hosford, 843 F.3d 161, 166 (4th Cir. 2016). The same findings 
apply to persons ``regularly'' manufacturing firearms. Like section 
922(a) of the GCA, the regulation ``imposes a mere condition or 
qualification. Though framed as a prohibition against unlicensed 
firearm [commerce], the law is in fact a requirement that those who 
engage in the [business] of firearms obtain a license.'' Id. And this 
licensing requirement ``is a crucial part of the federal regulatory 
scheme.'' Id. at 168; see also United States v. Focia, 869 F.3d 1269, 
1286 (11th Cir. 2017) (prohibiting transfers between unlicensed 
individuals in different states ``does not operate to completely 
prohibit [the defendant] or anyone else, for that matter, from selling 
or buying firearms;'' instead, it ``merely'' imposes ``conditions and 
qualifications on the commercial sale of arms'' (internal quotation 
marks omitted)); United States v. Nowka, 2012 WL 2862061, at *6 (N.D. 
Ala. May 10, 2012) (``[Plaintiff's] right to buy or sell a firearm is 
not abridged. It is regulated.'').
    In some ways similar to the regulation, but in other ways more far-
reaching, a San Diego City ordinance prohibits the possession, 
purchase, sale, receipt, and transportation of non-serialized firearms 
and unfinished frames and receivers. A lawsuit was brought challenging 
the ordinance as imposing ``a blanket prohibition'' upon a Second 
Amendment right to ``self-manufacture all firearms in common use for 
self-defense and other lawful purposes.'' Fahr v. City of San Diego, 
2021 WL 4895974, at *5 (S.D. Cal. Oct. 20, 2021). The district court 
disagreed, finding the ordinance ``neither strips

[[Page 24677]]

persons of access to any serialized, California-compliant firearm, 
including AR-15s, nor does it prevent persons from assembling any class 
of California-compliant firearm using pre-serialized frames or 
receivers.'' Id. at *6. The court further found that, assuming the 
ordinance regulates conduct protected by the Second Amendment, it 
``does not severely burden Second Amendment-protected conduct, but 
merely regulates it.'' Id. at *9; see also id. at *10 (because the 
ordinance ``targets only non-serialized firearms and unfinished frames 
and unfinished receivers . . . that bypass background checks . . . and 
that are untraceable . . . this Court finds that the Ordinance is a 
reasonable fit for achieving the City's objectives of decreasing the 
threat that ghost guns pose to the City's stated substantial and 
important interests,'' i.e., ``[p]ublic safety and crime prevention'').
    Further, where commenters believed that the rule would require them 
to mark their PMFs, they argued that imposing such marking requirements 
is unconstitutional under the Second Amendment because the right to 
build firearms dates back to the founding of the Republic. Some 
commenters also believed that requiring markings of any kind on 
firearms is unconstitutional under the Second Amendment. As stated 
above, in Marzzarella, the Third Circuit rejected as ``unavailing'' the 
premise that ``unmarked firearms'' are ``a constitutionally recognized 
class of firearms.'' 614 F.3d at 93. The court found that requiring a 
visible serial number ``d[oes] not bar'' an individual ``from 
possessing any otherwise lawfully marked firearm,'' id. at 94, and thus 
the ``burden imposed by the law does not severely limit the possession 
of firearms,'' id. at 97. Moreover, this requirement ``serves a law 
enforcement interest in enabling the tracing of weapons via their 
serial numbers'' and in ``assist[ing] law enforcement by making it 
possible to use the serial number of a firearm recovered in a crime to 
trace and identify its owner and source.'' Id. at 98; see also Fahr, 
2021 WL 4895974, at *10 (``It is a matter of common sense that tracing 
firearms enhances public safety and aids crime solving.'' (internal 
quotation marks omitted)); id. at *11 (``firearms tracing has become a 
critical tool for modern firearms investigations and prosecutions, 
which the prevalence of ghost guns threatens to upend'' (internal 
quotation marks omitted)).
    Although commenters argued that Heller established a 
``reasonableness'' standard under which the regulation fails because 
there is low usage of PMFs in crimes, this final rule provides revised 
information demonstrating that the number of suspected PMFs recovered 
at crime scenes has been increasing exponentially. As a matter of 
common sense, unserialized firearms are inherently attractive to 
criminals, and therefore pose a risk to public safety. And, as noted in 
Section II.B of this preamble, there has been a substantial increase in 
the number of PMFs recovered from crime scenes in recent years. The 
agency does not need to wait until a certain number of crimes are 
committed in order to address a growing problem. Moreover, this rule 
serves the compelling governmental interest of preventing unserialized 
firearms from proliferating throughout the country, as recognized in 
Marzzarella decision. Finally, this rule is not a prohibition, but only 
a regulation that imposes a minimal burden on the possession of 
firearms.
d. Violates the Fourth Amendment Right to Privacy
Comments Received
    Several commenters claimed the proposed rule violates their right 
to privacy under the Fourth Amendment. These commenters believe that 
the proposed rule requires persons to disclose firearms they have 
privately made on Form 4473, or that there is de facto registration 
occurring in the requirement that FFLs mark the PMFs they acquire. 
Other commenters stated that enforcement of the proposed rule would 
lead to a violation of their constitutional right to privacy in regards 
to their property if the government knows how many weapons each 
individual owns.
Department Response
    The commenters are not correct in their belief that the rule 
requires persons to disclose firearms they have made on Form 4473. 
Under the proposed and final rule, there are no recordkeeping or 
marking requirements for personal, non-NFA firearms that are privately 
made. As to the recordkeeping and marking requirements for the 
licensees engaged in the business of manufacturing or dealing in 
firearms, those records are not in the custody of the government, but 
are retained by the licensee until they discontinue business. See 18 
U.S.C. 923(g)(4). Additionally, while the proposed rule in no way 
establishes a registry of firearms, it is worthwhile noting that even 
actual registration of NFA firearms has never been found to violate a 
Fourth Amendment right to privacy.
    The Department also does not agree that the proposed rule violates 
a constitutional right to privacy in regard to commenters' property if 
the government knows how many weapons an individual possesses. ``The 
United States Constitution does not expressly guarantee a right to 
privacy, but the Supreme Court has held that a right to privacy does 
exist within the liberty component of the Fourteenth Amendment.'' See 
Padgett v. Donald, 401 F.3d 1273, 1280 (11th Cir. 2005). Courts have 
recognized a privacy interest in avoiding disclosure of certain 
personal matters. See id.
    ``[N]ot all disclosures of private information will trigger 
constitutional protection.'' Doe No. 1 v. Putnam County, 344 F. Supp. 
3d 518, 540 (S.D.N.Y. 2018) (finding courts have found a right to 
privacy in a ``limited set of factual circumstances'' involving one's 
personal financial or medical information, i.e., information of a 
``highly personal nature''). ``[T]he question is not whether 
individuals regard [particular] information about themselves as 
private, for they surely do, but whether the Constitution protects such 
information.'' DM v. Louisa County Dep't of Human Services, 194 F. 
Supp. 3d 504, 508-09 (W.D. Va. 2016) (finding no right to privacy of 
medical information) (internal quotation marks omitted). Information 
regarding firearms ownership or possession is of neither the medical 
nor financial variety, and no court has found this information to be 
constitutionally protected. See Doe 1, 344 F. Supp. 3d at 541 
(``Disclosure of one's name, address, and status as a firearms license 
[holder] is not one of the `very limited circumstances' in which a 
right to privacy exists.'').
e. Violates the Fifth Amendment--Unconstitutionally Vague
Comments Received
    Numerous commenters objected to the new definitions on grounds that 
the definitions are so vague that they violate the Due Process Clause 
of the Fifth Amendment. Citing to Christopher v. SmithKline Beecham 
Corp, 567 U.S. 142, 155-56 (2012), commenters stated that ATF must 
``provide regulated parties `fair warning of the conduct [the 
regulation] prohibits or requires' ''; otherwise, such ambiguity 
undermines due process and deprives market participants of notice about 
the law. Here, the commenters stated the definitions of ``firearms,'' 
``split or modular frame or receiver,'' and ``readily'' offer no clear 
guidance or clarity in determining the scope of the terms and therefore 
are impermissibly vague. Further, commenters stated that

[[Page 24678]]

because the only way the public can get clarity is through the non-
binding and non-public classification letters process, due process 
concerns are further compounded as entities are denied an opportunity 
to know what the law is and how to conform their conduct accordingly.
Department Response
    In light of the many cases rejecting such challenges, the 
Department does not believe the term ``readily'' is vague. Nonetheless, 
to avoid any doubt, the final rule provides additional clarity on the 
application of ``readily.'' The rule now expressly excludes from the 
definitions of ``frame or receiver,'' a ``forging, casting, printing, 
extrusion, unmachined body, or similar article that has not yet reached 
a stage of manufacture where it is clearly identifiable as an 
unfinished component part of a weapon (e.g., unformed block of metal, 
liquid polymer, or other raw material).'' Thus, the definition of 
``readily'' is not applied to items in a primordial state that are not 
clearly identifiable as unfinished weapon (i.e., pistol, revolver, 
rifle, or shotgun) frames or receivers. Moreover, the final rule 
explains that, when issuing a classification, the Director may consider 
any associated templates, jigs, molds, equipment, tools, instructions, 
guides, or marketing materials that are sold, distributed, or possessed 
with the item or kit, or otherwise made available by the seller or 
distributor of the item or kit, to the purchaser or recipient of the 
item or kit. The final rule further provides detailed examples of when 
an unfinished frame or receiver billet, blank, or parts kit may be 
considered a ``frame or receiver.'' For example, a partially complete 
billet or blank of a frame or receiver is a ``frame or receiver'' when 
it is sold, distributed, or possessed with a compatible jig or 
template, allowing a person using online instructions and common hand 
tools to complete the frame or receiver efficiently, quickly, and 
easily ``to function as a frame or receiver,'' a term which is also 
explained in the final rule. These revisions make it clear that 
manufacturers will be able to continue to obtain unfinished billets or 
blanks from their suppliers for further manufacture without requiring 
that the producer be licensed, mark such items, or maintain records of 
production and disposition. This is because their suppliers are not 
selling, distributing, or otherwise making available to their customers 
any jigs, templates, or other items that allow them to be readily 
converted to function as a frame or receiver.
    The Department disagrees with commenters that the explanation in 
the proposed rule of how ATF would determine which portion of a 
``firearm'' is a frame or receiver in a split or modular weapon, and 
what the term ``readily'' encompasses, is unconstitutionally vague. To 
begin, the rule explains ATF's understanding of the statutory terms at 
issue and describes how those terms apply to particular circumstances, 
thus providing greater clarity about the statutory terms involved. To 
the extent commenters are concerned that the statutory requirements are 
unclear, that is an objection about the statute, not the rule. In any 
event, however, the terms employed in the rule are not 
unconstitutionally vague. ``It is a basic principle of due process that 
an enactment is void for vagueness if its prohibitions are not clearly 
defined.'' Grayned v. City of Rockford, 408 U.S. 104, 108 (1972). A law 
is impermissibly vague if it ``fails to provide a person of ordinary 
intelligence fair notice of what is prohibited, or is so standardless 
that it authorizes or encourages discriminatory enforcement.'' FCC v. 
Fox Television Stations, Inc., 567 U.S. 239, 253 (2012) (internal 
quotation marks omitted). However, ``[c]ondemned to the use of words, 
we can never expect mathematical certainty from our language.'' 
Grayned, 408 U.S. at 110; see also Ward v. Rock Against Racism, 491 
U.S. 781, 794 (1989) (``perfect clarity and precise guidance have never 
been required even of regulations that restrict expressive activity'').
    Commenters objected to the term ``readily'' as vague. The term 
``readily'' is defined in the rule to explain when a partially 
complete, disassembled, or nonfunctional frame or receiver is 
considered a ``frame or receiver'' under 18 U.S.C. 921(a)(3)(B); when a 
weapon, including a weapon parts kit, is considered a ``firearm'' under 
18 U.S.C. 921(a)(3)(A); and when such frames or receivers are 
considered ``destroyed.'' These terms are easily understood to mean 
that if there is a weapon parts kit that may readily be completed, 
assembled, restored, or otherwise ``converted'' to a functional state 
(i.e., to expel a projectile), that parts kit is, itself, a 
``firearm.'' Likewise, it is easy to understand that if there is a 
partially complete, disassembled, or nonfunctional frame or receiver 
that may readily be completed, assembled, restored, or otherwise 
converted to a functional state (i.e., to house or provide a structure 
for the applicable fire control component), that housing or structure 
is, itself, a ``frame'' or ``receiver.'' No specialized knowledge is 
needed to understand how the term ``readily'' is to be applied. Persons 
who manufacture or possess weapon or frame or receiver parts kits, 
aggregations of parts, partially complete, or nonfunctional frames or 
receivers, are clearly on notice that what they are manufacturing, 
making, selling, distributing, receiving, or possessing are items 
subject to regulation if they only require minor additional work to be 
made functional. In sum, persons who make, transfer, receive, or 
possess partially complete firearm frames or receivers are on notice 
that those items are regulated if they may readily be converted.\78\ On 
the other end of the spectrum, it is easy for persons to comprehend 
that if what was a ``frame or receiver'' of a weapon can no longer 
function as such, and cannot efficiently, quickly, or easily be 
converted back to a functional state, that item is no longer a ``frame 
or receiver,'' or ``firearm,'' because it has been destroyed.
---------------------------------------------------------------------------

    \78\ Forgings, castings, extrusions, and machined bodies of 
firearms that are clearly identifiable as incomplete firearm frames 
or receivers have been regulated for purposes of importation and 
exportation as ``defense articles'' since at least 1939. See 
International Traffic in Arms, Ammunition, etc., 22 CFR 171.6, 1939 
Supp. 1318; 32 CFR 1.6, 1939 Supp. 2326 (now 22 CFR 120.6 and 27 CFR 
447.22). They are also considered ``imported parts'' for purposes of 
the prohibition against assembling nonsporting semiautomatic rifles 
or shotguns under 18 U.S.C. 922(r). See 27 CFR 478.39(c)(1). Under 
this rule, only forgings, castings, and machined bodies that are 
clearly identifiable as a component part of a weapon and that are 
designed to, or may readily be completed, assembled, restored, or 
otherwise converted to a functional state are regulated as 
``frames'' or ``receivers.''
---------------------------------------------------------------------------

    Moreover, ``readily'' has been repeatedly--and consistently--
defined by case law. In New York State Rifle & Pistol Ass'n v. Cuomo, 
804 F.3d 242 (2d Cir. 2015), the plaintiffs challenged a State statute 
criminalizing the possession of magazines that ``can be readily 
restored or converted to accept'' more than ten rounds of ammunition as 
vague because ``whether a magazine `can be readily restored or 
converted' depends upon the knowledge, skill, and tools available to 
the particular restorer.'' Id. at 266. The Second Circuit rejected that 
argument, finding that this ``statutory language dates at least to the 
1994 federal assault weapons ban'' and ``there is no record evidence 
that it has given rise to confusion at any time in the past two 
decades.'' Id.
    Indeed, ``readily'' dates back even further, appearing in the NFA's 
definition of ``machinegun,'' where it has repeatedly been upheld 
against vagueness challenges. See United States v. Catanzaro, 368 F. 
Supp. 450, 453-54 (D. Conn. 1973) (rejecting argument that

[[Page 24679]]

phrase ``which may be readily restored to fire'' in the NFA ``is not 
sufficiently definite to provide adequate warning as to the kinds of 
weapons included''); United States v. M-K Specialties Model M-14 
Machinegun, 424 F. Supp. 2d 862, 872 (N.D. W. Va. 2006) (the parties 
agreed ``the ordinary meaning of the term `readily restored' should be 
used when applying section 5845(b) [of the NFA] . . . the statute's 
terms should be easily understood by a person of ordinary 
intelligence'').\79\ While Congress did not define ``readily,'' courts 
have turned to the ``common practice of consulting dictionary 
definitions to clarify their ordinary meaning.'' United States v. TRW 
Rifle 7.62X51mm Caliber, One Model 14 Serial 593006, 447 F.3d 686, 689 
(9th Cir. 2006) (internal quotation marks omitted). The ``plain and 
unambiguous ordinary meaning of `readily' may be defined by a temporal 
component . . . or a component related to a manner or methodology'' and 
``must not be construed as an abstract phrase, but rather its contours 
should be determined in . . . context.'' Id. at 690 (internal quotation 
marks omitted).
---------------------------------------------------------------------------

    \79\ See also U.S. v. Wojcikiewicz, 403 F. App'x 483, 486 (11th 
Cir. 2010) (same with disassembled rifles); United States v. Kelly, 
No. 05-4775, 2007 WL 2309761, at *5 (4th Cir. Aug. 14, 2007) (the 
argument that 26 U.S.C. 5845(b) is unconstitutionally vague is 
meritless); United States v. Kent, 175 F.3d 870, 878 (11th Cir. 
1999) (rejecting vagueness challenge where disassembled short-
barreled Colt AR-15 could be readily restored to operate as a short-
barreled rifle); United States v. Drasen, 845 F.2d 731, 737-38 (7th 
Cir. 1988) (rejecting vagueness challenge to the phrase ``readily 
restored'' in 26 U.S.C. 5845(c) defining ``rifle''); U.S. v. M-K 
Specialties Model M-14 Machinegun, 424 F. Supp. 2d 862, 872 (N.D. W. 
Va. 2006) (rejecting vagueness challenge to the phrase ``readily 
restored'' in 26 U.S.C. 5845(b); cf. Phelps v. Budge, 188 F. App'x 
616, 618 (9th Cir. 2006) (Nevada statute defining deadly weapon as, 
among other things, any weapon or device which was ``readily capable 
of causing substantial bodily harm or death'' was not 
unconstitutionally vague); Coalition of New Jersey Sportsmen v. 
Whitman, 44 F. Supp. 2d 666, 681 (D.N.J. 1999), aff'd, 263 F.3d 157 
(3d Cir. 2001) (New Jersey statute criminalizing ``any combination 
of parts from which an assault firearm may be readily assembled'' 
was not unconstitutionally vague); Botosan v. Paul McNally Realty, 
216 F.3d 827, 836-37 (9th Cir. 2000) (term ``readily achievable'' 
and factors set forth in the Americans with Disabilities Act ``can 
hardly be considered vague''); United States v. Quiroz, 449 F.2d 
583, 585 (9th Cir. 1971) (the definition of ``firearm'' in section 
921(a)(3) was not unconstitutionally vague with respect to a 
``readily convertible'' starter gun); United States v. 16,179 Molso 
Italian .22 Caliber Winlee Derringer Convertible Starter Guns, 443 
F.2d 463, 464-65 (2d Cir. 1971) (same).
---------------------------------------------------------------------------

    The Department disagrees with commenters that the explanation in 
the proposed rule of how ATF would determine which portion of a 
``firearm'' is the frame or receiver in a split or modular weapon was 
unconstitutionally vague. ATF has applied that criteria for many 
decades as to split or modular weapons. Nonetheless, because the 
Department agrees with commenters that the definition of ``firearm'' in 
18 U.S.C. 921(a)(3)(B) is best read to mean a single part of a weapon 
or device as being ``the'' frame or receiver, the Department provides 
under the definition of ``frame or receiver'' new distinct sub-
definitions for frames with respect to handguns; receivers with respect 
to rifles, shotguns, and projectile weapons other than handguns; and 
frames or receivers for firearm mufflers and silencers. The final rule 
does not adopt the proposed supplement entitled ``Split or Modular 
Frame or Receiver.'' The final rule also provides illustrative examples 
of ATF's prior classifications that are grandfathered, and examples of 
when a partially complete, disassembled, or nonfunctional frame or 
receiver is considered readily completed, assembled, restored, or 
otherwise converted to a functional state. See Parker v. Levy, 417 U.S. 
733, 754 (1974) (examples provided ``considerable specificity'' of 
``the conduct which they cover''). With these clarifications in the 
final rule, licensees, and the public, can make their own 
determinations to identify the frame or receiver of a weapon without an 
ATF classification.
    These definitions use the terms with their ordinary meanings and in 
context, see TRW Rifle, 447 F.3d at 689, 690, and are sufficiently 
clear to ``give the person of ordinary intelligence a reasonable 
opportunity to know what is prohibited,'' Village of Hoffman Estates v. 
Flipside, Hoffman Estates, Inc., 455 U.S. 489, 498 (1982) (citing 
Grayned, 408 U.S. at 108-09). Absolute certainty is not required. See 
United States v. Hosford, 843 F.3d 161, 171 (4th Cir. 2016) (laws 
``necessarily have some ambiguity, as no standard can be distilled to a 
purely objective, completely predictable standard.''); Draper v. 
Healey, 827 F.3d 1, 4 (1st Cir. 2016) (``if due process demanded [a] 
how-to guide, swaths of the United States Code, to say nothing of state 
statute books, would be vulnerable''); United States v. Lachman, 387 
F.3d 42, 56 (1st Cir. 2004) (``The mere fact that a statute or 
regulation requires interpretation does not render it 
unconstitutionally vague.''); Kolbe v. O'Malley, 42 F. Supp. 3d 768, 
800 (D. Md. 2014) (A ``statute is not impermissibly vague simply 
because it does not spell out every possible factual scenario with 
celestial precision.'' (internal quotation marks omitted)).\80\
---------------------------------------------------------------------------

    \80\ Moreover, to the extent there is uncertainty about a 
particular item, upon submission, ATF will render a classification, 
a service ATF has long provided. See Sig Sauer, Inc. v. Brandon, 826 
F.3d 598, 599-600 (1st Cir. 2016); see also United States v. Zhen 
Zhou Wu, 711 F.3d 1, 15 (1st Cir. 2013) (rejecting a vagueness 
challenge to the regulatory framework of the Arms Export Control Act 
and noting there is a ``determination process'' to ``allow private 
parties to obtain an official government answer on whether an item 
is covered . . . before they engage in potentially unlawful conduct, 
a feature that further mitigates any concern about the law trapping 
[the] unwary'' (citation omitted)).
---------------------------------------------------------------------------

    Commenters cite to Christopher v. SmithKline Beecham Corp., 567 
U.S. 142, 155-56 (2012), but that case did not involve constitutional 
vagueness claims at all. It instead addressed when Auer deference is 
due to an agency's interpretation of its own ambiguous regulations. Id. 
Here, by contrast, ATF is promulgating new regulations implementing the 
NFA and GCA through a formal rulemaking procedure. And as explained 
above, the terms employed in this rule comport with ordinary usage and 
the case law interpreting those terms.
f. Violates the Fifth Amendment--Unconstitutional Taking
Comments Received
    Commenters opposed to the NRPM asserted that the regulations would 
result in an unconstitutional taking under the Fifth Amendment. 
Commenters claimed that the government is obligated to compensate 
people who lost money based on the agency's misrepresentations. One 
commenter argued that an unconstitutional taking would occur if FFLs 
are forced to either mark PMFs currently in their possession in 
accordance with the proposed rule, destroy the PMFs, or ``voluntarily'' 
turn the PMFs over to law enforcement officials within 60 days of the 
effective date of the final rule. The commenter claimed that the 
``voluntary'' surrender to law enforcement officials is a government 
taking of personal property. The commenter relied on Loretto v. 
Teleprompter Manhattan CATV Corp., 458 U.S. 419 (1982), where the 
Supreme Court explained that, with regard to the factual inquiry 
involved in a takings claim under Penn Central Transportation Co. v. 
New York City, 438 U.S. 104 (1978), a ``governmental action'' that 
results in ``a permanent physical occupation of property'' represents 
``a taking to the extent of the occupation, without regard to whether 
the action achieves an important public benefit or has only minimal 
economic impact on the owner.'' 458 U.S. at 434-

[[Page 24680]]

35. The commenter claimed that absent specific asset forfeiture 
instructions directing Federal law enforcement agencies to destroy any 
PMFs ``voluntarily'' turned in by FFLs, the proposed rule fails to set 
forth any safeguards that prevent Federal law enforcement agencies from 
repurposing the PMFs for their own use and therefore effectuates a 
regulatory taking of private property without just compensation.
Department Response
    The Department disagrees that the regulation constitutes a taking, 
and further disagrees that it results in a compensable taking. In order 
to remain in compliance, FFLs are not required to destroy unmarked PMFs 
or surrender them to ATF. They can mark them, or have them marked, as 
required by regulation, which does not require any transfer or loss of 
property. However, if an FFL chooses to destroy a PMF, that is not 
compensable. Moreover, the Federal Circuit has recognized that, under 
Supreme Court precedent, there are certain exercises ``of the police 
power that ha[ve] repeatedly been treated as legitimate even in the 
absence of compensation to the owners of the . . . property.'' Acadia 
Tech., Inc. v. United States, 458 F.3d 1327, 1332-33 (Fed. Cir. 2006). 
As the Supreme Court articulated the doctrine, ``[a] prohibition simply 
upon the use of property for purposes that are declared, by valid 
legislation, to be injurious to the health, morals, or safety of the 
community, cannot, in any just sense, be deemed a taking or an 
appropriation of property for the public benefit.'' Mugler v. Kansas, 
123 U.S. 623, 668-69 (1887); see Acadia Tech., 458 F.3d at 1333.
    The Federal Circuit has applied this precedent in situations where 
Federal law enforcement has acted pursuant to seizure statutes, and 
criminal laws, to find that no compensable taking exists. AmeriSource 
Corp. v. United States, 525 F.3d 1149, 1154 (Fed. Cir. 2008); Acadia 
Tech., 458 F.3d at 1333. In doing so, the court emphasized that 
``[p]roperty seized and retained pursuant to the police power is not 
taken for a `public use' in the context of the Takings Clause.'' 
AmeriSource, 525 F.3d at 1153. In these decisions, the Federal Circuit 
found no taking occurs irrespective of whether the government had 
physically seized the property or rendered it worthless. Id. at 1153-
54; Acadia, 458 F.3d at 1333.
    The Federal Circuit and the Court of Federal Claims have also made 
clear that these principles apply with full force in analyzing the 
impact of firearms regulations promulgated pursuant to the Federal 
power to regulate commerce. In Mitchell Arms, Inc. v. United States, 7 
F.3d 212 (Fed. Cir. 1993), the Federal Circuit rejected a takings claim 
brought by a firearms business whose permits to import semiautomatic 
rifles were revoked. Similarly, in Akins v. United States, 82 Fed. Cl. 
619 (2008), the Court of Federal Claims rejected takings claims, 
including a per se takings claim, after ATF reconsidered its prior 
classification decisions regarding the Akins Accelerator. The Court 
explained that ``[p]roperty seized and retained pursuant to the police 
power is not taken for a `public use' in the context of the Takings 
Clause.'' Id. at 622 (quoting AmeriSource, 525 F.3d at 1153). And, 
citing Mitchell Arms, the Akins Court also found that the plaintiff was 
fully aware of the ``potential for federal regulation of his 
invention'' and his ``expectation interest'' was ``not a property 
interest protected by the Fifth Amendment.'' Id. at 624; see also 
Maryland Shall Issue v. Hogan, 353 F. Supp. 3d 400, 408-17 (D. Md. 
2018) (rejecting takings claim arising from State ban on bump stocks), 
aff'd, 963 F.3d 356 (4th Cir. 2020); cf. McCutchen v. United States, 14 
F.4th 1355, 1364-65 (Fed. Cir. 2021) (rejecting takings claim on the 
``related'' ground that no taking occurs where the government ``asserts 
a pre-existing limitation upon the [property] owner's title'' to 
require destruction of a banned weapon (internal quotation marks 
omitted)). Even under a takings analysis, the regulation would be 
analyzed under Penn Central, and the regulation would be upheld. Under 
Penn Central, a court considers: (1) The economic impact of the 
regulation on the claimant, (2) its interference with investment-based 
expectations, and (3) the character of the governmental action. 438 
U.S. at 124.
    No taking exists under Penn Central. A restriction ``directed at 
the protection of public health and safety . . . is the type of 
regulation in which the private interest has traditionally been most 
confined and governments are given the greatest leeway to act without 
the need to compensate those affected by their actions.'' Rose Acre 
Farms, Inc. v. United States, 559 F.3d 1260, 1281 (Fed. Cir. 2009). A 
plaintiff's ``reasonable investment-backed expectations are greatly 
reduced in a highly regulated field,'' Branch v. United States, 69 F.3d 
1571, 1581 (Fed. Cir. 1995), such as the firearms industry. And as the 
Supreme Court has made clear, ``an owner of personal property `ought to 
be aware of the possibility that new regulation might even render his 
property economically worthless.' '' See Lucas v. S.C. Costal Council, 
505 U.S. 1003, 1027-28 (1992). As for the economic impact, licensees do 
not have to abandon or destroy anything; they need only mark PMFs with 
serial numbers as required by the GCA if they choose to take those 
items into inventory.
    Commenters' citation to Loretto is inapplicable. The Loretto 
decision states nothing about regulating the possession of inherently 
dangerous personal property. Instead, Loretto involved a challenge to a 
state law requiring a landlord to install cable television facilities 
on the landlord's building. 458 U.S. at 421. The Court found a per se 
physical taking based upon the physical invasion of the landlord's real 
property. Id. at 426. Here, in contrast, the government has not 
required anyone to transfer title of anything to the government and has 
not physically invaded anyone's property. Moreover, even the physical 
seizure of highly regulated goods pursuant to the government's police 
power has never been thought to constitute a per se taking. See Kam-
Almaz v. United States, 682 F.3d 1364, 1372 (Fed. Cir. 2012); 
AmeriSource, 525 F.3d at 1153; Acadia Tech., 458 F.3d at 1332-33.
    To the extent commenters are arguing that a categorical regulatory 
taking under Lucas has occurred, they are incorrect. First, the Lucas 
test does not apply to valid exercises of the government's police power 
in enforcing the criminal laws. That is the case even where personal 
property may become worthless as a result of the government's action, 
which is not the case here. See AmeriSource, 525 F.3d at 1154; Akins, 
82 Fed. Cl. at 621-23. Lucas also does not apply to the regulation of 
personal property of the type involved here. The Supreme Court has 
never held that even a complete ban on possessing dangerous personal 
property constitutes a per se taking under Lucas (or any per se test). 
The Supreme Court has explained that the categorical takings analysis 
applies only in the ``relatively rare'' and ``extraordinary 
circumstance when no productive or economically beneficial use of land 
is permitted.'' Lucas, 505 U.S. at 1017-18. Although the Court has had 
reason to consider Lucas on multiple occasions, it has never applied 
the rule to any type of property rights other than real property. See 
McCutchen, 14 F.4th at 1371-72 (``The cases in which the Supreme Court 
has applied Lucas's total takings rule have involved real property, and 
Circuit Courts have not reached a clear consensus on how broadly to 
apply Lucas's per se rule.'') (Wallach, J., concurring in result).

[[Page 24681]]

g. Violates the Fifth Amendment--Equal Protection Clause
Comments Received
    Several commenters claimed that the proposed rule violates the 
Equal Protection Clause by targeting the products of certain law-
abiding businesses, including by naming particular companies.\81\
---------------------------------------------------------------------------

    \81\ For example, Blackhawk Manufacturing Group objected to the 
inclusion of its website address, and claimed it was being targeted 
because ``ATF seeks to put [it] out of business.'' This is 
inaccurate. If Blackhawk Manufacturing Group is interested in 
engaging in the business of manufacturing firearms, it need only 
apply for a license like other commercial firearms manufacturers.
---------------------------------------------------------------------------

Department Response
    The Department disagrees that the proposed rule violates the Equal 
Protection Clause. If a ``classification `impermissibly interferes with 
the exercise of a fundamental right or operates to the peculiar 
advantage of a suspect class,' [a court will] subject the 
classification to strict scrutiny. Otherwise, [courts] will uphold the 
classification if it is `rationally related to a legitimate state 
interest.' '' Mance v. Sessions, 896 F.3d 699, 711 (5th Cir. 2018) 
(citing NRA v. ATF, 700 F.3d 185, 211-12 (5th Cir. 2012)). There is no 
fundamental right to be engaged in the business of manufacturing 
firearms or to possess unserialized firearms. See Defense Distributed, 
121 F. Supp. 3d at 699; Marzzarella, 614 F.3d at 93. Nor are firearms 
manufacturers a suspect class. Rational basis review therefore applies.
    Under rational basis review, a classification ``is accorded a 
strong presumption of validity.'' Heller v. Doe by Doe, 509 U.S. 312, 
319 (1993). ``The firearm regulatory scheme . . . is consonant with the 
concept of equal protection embodied in the Due Process Clause of the 
Fifth Amendment if there is some rational basis for the statutory 
distinctions made . . . or they have some relevance to the purpose for 
which the classification is made.'' Lewis v. United States, 445 U.S. 
55, 65 (1980) (internal quotation marks omitted).
    There is clearly a rational basis for requiring those engaged in 
the business of manufacturing firearms to be licensed and serialize 
their firearms. The ``principal purpose'' of the GCA is to curb crime 
by keeping ``firearms out of the hands of those not legally entitled to 
possess them.'' Huddleston v. United States, 415 U.S. 814, 824 (1974) 
(internal quotation marks omitted). As a result, ``[c]ommerce in 
firearms is channeled through federally licensed importers, 
manufacturers, and dealers in an attempt to halt mail-order and 
interstate consumer traffic in these weapons.'' Id.; see also United 
States v. Biswell, 406 U.S. 311, 315 (1972) (``[C]lose scrutiny'' of 
``interstate traffic in firearms'' is ``undeniably of central 
importance to federal efforts to prevent violent crime and to assist 
the States in regulating the firearms traffic within their borders.''); 
id. at 315-16 (``Federal regulation'' of the traffic in firearms 
``assures that weapons are distributed through regular channels and in 
a traceable manner.''); United States v. Hosford, 82 F. Supp. 3d 660, 
667 (D. Md. 2015) (prohibiting engaging in the business of firearms 
without a license ``ensures that significant commercial traffic in 
firearms will be conducted only by parties licensed by the federal 
government''); id. (``Nor is the licensing requirement onerous.''); 
Marzzarella, 614 F.3d at 100 (requiring serial numbers not only allows 
for the ``tracing of the chain of custody of firearms involved in 
crimes,'' but also ``provides agencies with vital criminology 
statistics,'' ``as well as allowing for the identification of 
individual dealers involved in the trafficking of firearms and the 
matching of ballistics date with recovered firearms''); United States 
v. Adams, 305 F.3d 30, 34 (1st Cir. 2002) (``[A]nyone can see what 
Congress was getting at[;]'' the serial number is the ``principal means 
of tracing origin and transfers in ownership.'') And, as stated above, 
public safety and crime prevention are compelling governmental 
interests.
2. Statutory Authority Concerns
a. Lack of Delegated Authority To Promulgate the Rule
Comments Received
    A majority of commenters opposed to the NPRM argued that ATF is 
exceeding its authority by promulgating the rule and that it is the job 
of Congress to change the laws and the job of Federal agencies to 
enforce them. Because the NPRM explained that the agency is changing 
its regulations in response to the manner in which courts have ruled on 
the AR-15-type firearm receiver, commenters stated that it is 
Congress's role to amend the law if the law has become out of date and 
that this power cannot be usurped by a non-legislative governmental 
entity.
    Other commenters argued that ATF's authority to enact regulations 
is constrained under 18 U.S.C. 926. They pointed to the Firearms 
Owners' Protection Act of 1986 (``FOPA'') and its accompanying 
legislative history, when Congress amended section 926 by deleting the 
discretionary language that allowed the Secretary to ``prescribe such 
rules and regulations as he deems reasonably necessary to carry out the 
provisions of this chapter.'' Commenters stated the prior language was 
a broader standard and it was amended to the current language, which 
only allows the Attorney General to ``prescribe only such rules and 
regulations as necessary to carry out the provisions of this chapter.'' 
Further, the commenters stated that none of the examples provided in 
section 926(a) ``indicate[s] any intention of Congress to delegate to 
the ATF the power to define the items regulated under the GCA . . . in 
a manner that expands or contracts the scope of the GCA. Rather, [the] 
examples reinforce Congressional [sic] to severely limit ATF's 
authority to those required to carry out the administration of the 
provisions contained within the GCA.''
    Other commenters argued that ATF lacks the authority to act because 
it is in violation of the non-delegation doctrine, which asks ``whether 
Congress has supplied an intelligible principle to guide the delegee's 
use of discretion.'' Gundy v. United States, 139 S. Ct. 2116, 2123 
(2019). Specifically, they argued that the GCA contains no intelligible 
principle to guide ATF's rulemaking authority nor provides any 
standards for the Department or ATF to redefine statutory definitions. 
Instead, the commenters asserted, the Attorney General's rulemaking 
authority is limited to 18 U.S.C. 926(a). Another commenter wrote that 
``nothing grants ATF or any other agency the discretion to modify this 
command'' in the GCA that all firearms must bear a serial number 
although ATF has the ability to provide the practical details of how 
the marking is to be done. However, the commenter argued the proposed 
rule grants ATF far too much discretion in deciding which firearms it 
will regulate and would open ``a floodgate of policymaking discretion 
that the GCA does not and cannot grant to it.'' Many other commenters 
raised specific arguments that ATF's newly proposed and revised 
definitions, as well as other proposed marking and recordkeeping 
requirements on FFLs, are contrary to the GCA. Those separate specific 
arguments are explained in further detail below. See Sections IV.B.2.b-
f of this preamble.
Department Response
    The Department disagrees that ATF lacks the delegated legal 
authority to promulgate rules that are necessary to implement the GCA 
and the NFA, including the definitions of ``frame or receiver'' 
promulgated by the predecessor agency to ATF. The

[[Page 24682]]

Department's and ATF's legal authority includes the authority to 
promulgate regulations and rules implementing and interpreting the GCA 
and NFA, to specify the information and period by which firearms are 
required to be marked pursuant to the GCA and NFA, and to specify the 
precise period and form in which Federal firearm licensee records 
required by the GCA and NFA are maintained.\82\ Congress and the 
Attorney General have delegated the responsibility for administering 
and enforcing the GCA and NFA to the Director of ATF, subject to the 
direction of the Attorney General and the Deputy Attorney General. See 
26 U.S.C. 7801(a)(2); 28 U.S.C. 599A(b)(1), (c)(1); 28 CFR 0.130(a)(1)-
(2); T.D. Order No. 221(2)(a), (d), 37 FR 11696-97 (June 10, 1972). 
``Because Sec.  926 authorizes the [Attorney General] to promulgate 
those regulations which are `necessary,' it almost inevitably confers 
some measure of discretion to determine what regulations are in fact 
`necessary.' '' Nat'l Rifle Ass'n v. Brady, 914 F.2d 475, 479 (4th Cir. 
1990). And courts have long recognized that regulatory agencies do not 
establish rules to last forever. ``They are neither required nor 
supposed to regulate the present and the future within the inflexible 
limits of yesterday.'' Am. Trucking Ass'n v. Atchison, Topeka, and 
Santa Fe Ry. Co, 387 U.S. 397, 416 (1967).
---------------------------------------------------------------------------

    \82\ In this regard, the GCA and NFA include both general and 
specific delegations of rulemaking authority. Compare 18 U.S.C. 
926(a) (``The Attorney General may prescribe only such rules and 
regulations as are necessary to carry out the provisions of this 
chapter . . . .''); H.R. Rep. No. 90-1577, at 18 (June 21, 1968) 
(``Section 926. Rules and regulations. This section grants 
rulemaking authority to the Secretary . . . .''); S. Rep. No. 90-
1501, at 39 (Sept. 6, 1968) (same), and 26 U.S.C. 7805(a) (``the 
[Attorney General] shall prescribe all needful rules and regulations 
for the enforcement of this title, including all rules and 
regulations as may be necessary by reason of any alteration of law 
in relation to internal revenue.''), with 18 U.S.C. 921(a)(13) 
(``The term `collector' means any person who acquires, holds, or 
disposes of firearms as curios or relics, as the Attorney General 
shall by regulation define . . . .''); id. sec. 923(g)(1)(A) (``Each 
licensed importer, licensed manufacturer, and licensed dealer shall 
maintain such records of importation, production, shipment, receipt, 
sale, or other disposition of firearms at his place of business for 
such period, and in such form, as the Attorney General may by 
regulations prescribe.''); id. sec. 923(g)(2) (``Each licensed 
collector shall maintain in a bound volume the nature of which the 
Attorney General may by regulations prescribe, records of the 
receipt, sale, or other disposition of firearms.''); id. sec. 923(i) 
(``Licensed importers and licensed manufacturers shall identify by 
means of a serial number engraved or cast on the receiver or frame 
of the weapon, in such manner as the Attorney General shall by 
regulations prescribe, each firearm imported or manufactured by such 
importer or manufacturer.''); 26 U.S.C. 5841(c) (``Each manufacturer 
shall notify the Secretary of the manufacture of a firearm in such 
manner as may by regulations be prescribed . . . .''); id. sec. 
5842(a) (``Each manufacturer and importer and anyone making a 
firearm shall identify each firearm, other than a destructive 
device, manufactured, imported, or made by a serial number which may 
not be readily removed, obliterated, or altered, the name of the 
manufacturer, importer, or maker, and such other identification as 
the [Attorney General] may by regulations prescribe.''); and id. 
sec. 5843 (``Importers, manufacturers, and dealers shall keep such 
records of, and render such returns in relation to, the importation, 
manufacture, making, receipt, and sale, or other disposition, of 
firearms as the [Attorney General] may by regulations prescribe.'').
---------------------------------------------------------------------------

    As to comments asserting that the GCA's various delegations of 
rulemaking authority to the Attorney General and ATF violate the non-
delegation doctrine, the Supreme Court has consistently rejected 
similar arguments with respect to public safety statutes. See Whitman 
v. American Trucking Ass'ns, 531 U.S. 457, 474 (2001) (``[W]e have 
found an ``intelligible principle'' in various statutes authorizing 
regulation in the `public interest.' '' (collecting cases)). The 
definitions and requirements established by this rule are all guided by 
the intelligible principles set forth in the GCA governing the 
manufacture, importation, dealing, and collecting of firearms, 
including licensing, marking, recordkeeping, background checks, and 
crime gun tracing.\83\
---------------------------------------------------------------------------

    \83\ Cf. Cargill v. Barr, 502 F. Supp. 3d 1163, 1188 (W.D. Tex. 
2020), aff'd on other grounds, 20 F.4th 1004, 1014 (5th Cir. 2021) 
(``The delegations of authority supporting the Final Rule [defining 
``machinegun''] also do not violate non-delegation principles 
because 18 U.S.C. 926(a) only permits the Attorney General to 
`prescribe such rules and regulations as are necessary to carry out 
the provisions of [the GCA]' and 26 U.S.C. 7805 provides similar 
authority for `all needful rules and regulations for the enforcement 
of [the NFA].' 18 U.S.C. 926(a); 26 U.S.C. 7805(a). Given that the 
Supreme Court has `over and over upheld even very broad 
delegations,' like ones requiring an agency merely `to regulate in 
the ``public interest,' '' the delegations underlying the Final Rule 
pass the `intelligible principle' test.'').
---------------------------------------------------------------------------

b. Lack of Authority To Regulate Multiple Parts as ``Frames or 
Receivers''
Comments Received
    A large number of commenters objected to the proposed definition of 
``firearm frame or receiver'' and, in particular, the supplemental 
definition of ``split or modular frame or receiver.'' Commenters stated 
that the statute is clear that a firearm has only one, singular frame 
or receiver and that Congress (as ATF pointed out in its NPRM) elected 
not to regulate all firearms parts when it repealed the FFA and revised 
the definition of ``firearm'' in 1968 when passing the GCA. According 
to these commenters, contrary to the intent of Congress, the NPRM's 
definition of frame or receiver would return to regulating individual 
firearm parts by allowing several parts to be considered the frame or 
receiver. Several commenters stated that Congress knew how to 
distinguish between a whole and parts of a whole. For example, Congress 
included both the whole and any one of the individual constituent parts 
in the definition of a silencer or a muffler, which is defined in 18 
U.S.C. 921(a)(24) as ``any combination or parts . . . and any part 
intended for use in such assembly or fabrication,'' and a ``handgun'' 
is defined in 18 U.S.C. 921(a)(29) as ``any combination of parts . . . 
.'' If Congress had intended multiple parts of other firearms to be 
``firearms,'' it could have used similar language. Moreover, Congress 
has amended the GCA several times without redefining the terms at 
issue.
    At least one commenter rejected ATF's reliance on the series of tax 
cases listed in the NPRM as authority for interpreting statutory 
definitions to avoid clear error in applying the law. The commenter 
stated that the Department is not interpreting clear error, but instead 
is rewriting the law. Some commenters also highlighted Niz-Chavez v. 
Garland, 141 S. Ct. 1474 (2021), a recent Supreme Court case that 
examined another Federal statute with a singular article before a 
defined term. In Niz-Chavez, the Court evaluated whether an immigration 
statute's requirement to send ``a notice'' with certain information was 
met when the government sent multiple notices, each of which did not 
contain all of the information required by the statute. The Court 
applied a plain reading of the text and said the government must send a 
single notice. Id. at 1486. In holding that a singular usage 
controlled, the Court in Niz-Chavez rejected the government's attempt 
to use the Dictionary Act as a way to pluralize the otherwise singular 
text of the term, stating ``[t]he Dictionary Act does not transform 
every use of the singular `a' into the plural `several.' '' Id. at 
1482.
    Many other commenters disagreed with ATF's claim that single frames 
or receivers were more prevalent for civilian use over split or multi-
piece receivers at the time of the GCA's enactment and issuance of the 
original implementing regulations. One commenter provided copies of 
historical materials on firearms, including from the Department of 
Defense, to support his assertion that Members of Congress in 1967, 
many of whom had served in World War II, would have been personally 
familiar with ``new-fangled'' rifles that had an upper and a lower 
receiver. For this reason, the commenter asserted that it is, 
therefore, not possible for ATF to argue that Congress did not know 
there were rifles with upper and

[[Page 24683]]

lower receivers when re-defining ``firearm'' to include ``the frame or 
receiver'' instead of ``any part or parts of such weapon.'' Other 
commenters also pointed to specific models designed for the military 
that found their way into common use after World War I, including the 
1911 pistol and the Thompson gun.
    One commenter, who is a manufacturer, also cited a 1971 Treasury 
Memorandum on the M16 receiver to show that when ATF was part of the 
Department of the Treasury, the agency had considered split or multi-
piece receiver firearms during the initial rulemaking process but felt 
it impracticable to do so. The author of the 1971 memorandum stated the 
``M-16 receiver is fabricated in two parts . . . . Both parts were 
necessary to function as a `frame or receiver . . . .' I can see some 
difficulty in trying to make cases against persons possessing only the 
lower part of the receiver, but insofar as licensing, serial numbering, 
and special occupational tax requirements are concerned, I feel that 
[serializing the lower] is the only practical solution.'' See CC: ATF-
12,736, Subject: M16 Receivers, Internal Revenue Service, Department of 
the Treasury (March 1, 1971).
Department Response
    Although the Department disagrees with numerous commenters who 
claim that the term ``frame or receiver'' in 18 U.S.C. 921(a)(3)(B) 
must be read to mean that a firearm may not have more than one frame or 
receiver, the Department has decided to alter the proposed definition 
in this final rule in response to comments.\84\ The Department agrees 
with commenters that section 921(a)(3)(B) must be read in context, and 
recognizes that the Supreme Court in Niz-Chavez instructs courts to 
exhaust all textual and structural clues bearing on the meaning of a 
statutory term. 141 S. Ct. at 1480. The statutory term in question is 
``the frame or receiver of any such weapon'' (emphasis added). 
Unfortunately, here, there are contextual and structural clues that 
point in different directions. On one hand, ``the frame or receiver of 
any such weapon'' refers to a weapon in section 921(a)(3)(A), and that 
definition uses a singular article when referring to more than one 
firearm design. For example, section 921(a)(3)(A) states that a 
``firearm'' includes ``any weapon . . . which will or is designed to . 
. . expel a projectile by the action of an explosive'' (emphasis 
added). By using the singular term ``a,'' Congress clearly did not mean 
to regulate only those weapons that will or are designed to expel only 
a single projectile. Almost all firearms are designed to expel more 
than one projectile after the first, and numerous firearm designs, such 
as shotguns and machineguns, will expel multiple projectiles at the 
same time. Moreover, as one commenter pointed out, one major design of 
a ``firearm'' under 18 U.S.C. 921(a)(3)(A) is a handgun, and the 
definition of ``handgun'' in 18 U.S.C. 921(a)(29)(B) includes ``any 
combination of parts from which a [handgun] can be assembled.'' \85\ 
Thus, it is possible that the term ``frame,'' for example, could be 
referring to multiple frames within a handgun, or both a frame and a 
receiver in a split handgun design.\86\
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    \84\ The Dictionary Act recognizes that ``[i]n determining the 
meaning of any Act of Congress, unless the context indicates 
otherwise, words importing the singular include and apply to several 
persons, parties, and things.'' 1 U.S.C. 1; see also Niz-Chavez, 141 
S. Ct. at 1482 (the Dictionary Act tells us that a statute using the 
singular can apply to multiple persons, parties, or things); Barr v. 
United States, 324 U.S. 83, 91 (1945) (citing 1 U.S.C. 1 as 
authority for construing the statutory term ``buying rate'' to 
include more than one buying rate); Day v. Sec. of Health & Human 
Services, 129 Fed. Cl. 450, 452 (2016) (``The mere use of terms in 
the singular, of course, hardly provides the context for escaping 
the ambit of the Dictionary Act rule regarding the use of the 
singular.''); Georgetown Univ. Hospital v. Sullivan, 934 F.2d 1280, 
1283-84 (D.D.C. 1991) (use of definite article ``the'' with the 
singular word ``amount'' did not preclude the possibility there may 
be more than one ``amount'').
    \85\ The Department recognizes that ``combinations of parts'' 
was added to the definition of ``handgun'' in the GCA by section 102 
of the Brady Handgun Violence Protection Act, Public Law 103-159 
(1993).
    \86\ Cf. United States v. Morales, 280 F. Supp. 2d 262, 273 
(S.D.N.Y. 2003) (``[T]he different parts represented in Exhibit J to 
the Becker Affirmation include both the ``frame'' and the 
``receiver'' of a Tec-9 pistol, and are therefore explicitly covered 
under the language of 18 U.S.C. 921(a)(3)(B).'').
---------------------------------------------------------------------------

    On the other hand, the marking requirement for manufacturers and 
importers, 18 U.S.C. 923(i), refers to identifying ``a'' serial number 
on ``the'' receiver or frame of the weapon. And the GCA similarly 
amended the definition of ``machinegun'' in the NFA at 26 U.S.C. 
5845(b) to refer to a singular component when including ``the'' frame 
or receiver of any such weapon. The Department agrees with numerous 
commenters that the context of the singular terms ``frame'' and 
``receiver'' in these provisions suggests that a firearm only has one 
frame or receiver. This reading is more consistent with the GCA's 
legislative history explaining that Congress found it impractical to 
treat each small part of a firearm as if it were a weapon capable of 
firing.\87\
---------------------------------------------------------------------------

    \87\ See Juvenile Delinquency: Investigation of Juvenile 
Delinquency in the United States: Hearing before the S. Comm. on the 
Judiciary, 88th Cong. (1963) (technical memorandum of Internal 
Revenue Service) (``The present definition [of ``firearm''] includes 
any `part' of a weapon within the term. It has been found that it is 
impracticable, if not impossible, to treat all parts of a firearm as 
if they were a weapon capable of firing. This is particularly true 
with respect to recordkeeping provisions since small parts are not 
easily identified by a serial number. Accordingly, there are no 
objections to modifying the definition so that all parts, other than 
frames or receivers, are eliminated. It should be noted that this 
amendment to the definition of `firearm' eliminates all parts of a 
weapon, other than receivers and frames, from the provisions of the 
act.'').
---------------------------------------------------------------------------

    After carefully considering the numerous comments submitted on this 
issue, the Department agrees that reading the GCA to encompass only one 
single part of a given weapon would greatly reduce the possibility that 
a modified weapon might have more than one serial number. Having more 
than one serial number per firearm would make it more difficult and 
costly for licensees to mark firearms and maintain associated records, 
and for law enforcement to trace firearms used in crime. Because the 
NPRM contemplated the possibility that a given firearm under the 
proposed rule would have more than one frame or receiver with different 
serial numbers, the Department is responding to the concerns of those 
comments by focusing on three subsets of the proposed definition of 
``frame or receiver.'' Specifically, the final rule defines that term 
to mean a housing or structure for a single fire control component--
``frame'' for handguns and variants thereof; ``receiver'' for rifles, 
shotguns, and projectile weapons other than handguns and variants 
thereof; and ``frame'' or ``receiver'' for firearm muffler or silencer 
devices.
    Finally, to ease the transition to the new definitions and marking 
requirements, the Department will grandfather existing split frame or 
receiver designs previously classified by ATF as the firearm ``frame or 
receiver'' prior to the issuance of this rule (except for certain 
partially complete, disassembled, or nonfunctional frames or receivers, 
to include weapon or frame or receiver parts kits). For example, the 
lower receiver of the AR-15-type rifle and variants thereof are 
expressly included within the new definition of ``receiver'' and may be 
marked according to the rules that existed before this rule.\88\
---------------------------------------------------------------------------

    \88\ However, the Department disagrees with commenters who 
suggested that the AR-15 rifle was in common civilian (i.e., non-
military or law enforcement) use in the United States when ATF's 
predecessor agency originally promulgated its regulatory definitions 
of ``frame or receiver'' in 1968 (Part 478) and 1971 (Part 479). 
While millions of AR-15s/M-16s existed at the time ATF promulgated 
the definitions, the vast majority were manufactured for military 
use. See Internal Colt Memorandum from B. Northrop, Feb. 2, 1973, p. 
2 (noting that there were 2,752,812 military versus 25,774 civilian 
(``Sporters'') serialization of AR-15/M-16 rifles then 
manufactured).

---------------------------------------------------------------------------

[[Page 24684]]

c. Lack of Authority To Regulate Weapon Parts Kits
Comments Received
    Commenters opposed to the NPRM specifically argued that ATF did not 
have the authority to amend the regulatory definition of ``firearm'' to 
include weapon parts kits because it runs contrary to the GCA's 
definition of firearm. Commenters stated that the definition of 
``firearm'' cannot be read, and has not been read in the cases cited by 
ATF, to include a kit containing parts that could be used to make a 
weapon because a kit is not itself a weapon. They stated that section 
921(a)(3)(A) is clear that a firearm is a ``weapon that can be readily 
converted to expel . . . , not the parts that can readily be converted 
to expel a projectile.'' Further, commenters argued that including 
weapon parts kits would impermissibly expand and alter the statutory 
meaning of both ``converted'' and ``readily.'' They stated that ATF 
cannot equate ``converted'' with the proposed added words 
``assembled,'' ``completed,'' or ``restored,'' and that, under a plain 
English reading, one would not ``convert'' these parts into a weapon. 
The GCA uses a starter gun as an example of an existing item that can 
be converted. Even assuming the definition includes ``assembled,'' the 
commenter stated that ``[a] weapon parts kit that does not contain most 
of the necessary components, or that needs machining, cannot be 
assembled (or converted) `readily' i.e., `without much difficulty' or 
`with fairly quick efficiency.' ''
Department Response
    The Department disagrees with commenters and believes the language 
of section 921(a)(3)(A) should be read to include weapon parts kits and 
aggregations of weapon parts that: (1) Are actually designed to expel a 
projectile by the action of an explosive in their present form or 
configuration, but cannot expel a projectile due to damage, poor 
workmanship, or design flaw or feature regardless of whether they may 
readily be made to function; or (2) may or may not be designed to expel 
a projectile by the action of an explosive in their present form or 
configuration, but may readily be converted to do so. The Federal 
courts that have addressed this issue have uniformly held that 
disassembled aggregations of weapon parts \89\ and weapon parts kits 
\90\ that may readily be converted to expel a projectile are 
``firearms'' under 18 U.S.C. 921(a)(3)(A).
---------------------------------------------------------------------------

    \89\ See, e.g., United States v. Annis, 446 F.3d 852, 857 (8th 
Cir. 2006) (partially disassembled rifle that could easily be made 
operational was a firearm under section 921(a)(3)(A)); United States 
v. Ryles, 988 F.2d 13, 16 (5th Cir. 1993) (disassembled shotgun was 
a firearm because it could have been readily converted to an 
operable firearm); United States v. Theodoropoulos, 866 F.2d 587, 
595 n.3 (3d Cir. 1989) (machine pistol that was disassembled that 
could easily be made operable); Enamorado v. United States, No. C16-
30290-MWB, 2017 WL 2588428, at *6 (N.D. Iowa June 14, 2017) 
(disassembled .45 caliber handgun that could easily be reassembled); 
United States v. Morales, 280 F. Supp. 2d 262, 272-73 (S.D.N.Y. 
2003) (partially disassembled Tec-9 pistol that could be assembled 
within short period of time could readily be converted to expel a 
projectile); United States v. Randolph, No. 02 CR. 850-01 (RWS), 
2003 WL 1461610, at *2 (S.D.N.Y. Mar. 20, 2003) (gun consisting of 
``disassembled parts with no ammunition, no magazine, and a broken 
firing pin, making it incapable of being fired without replacement 
or repair'' was a ``firearm'' because it could be readily converted 
to expel a projectile and included the frame or receiver of any such 
weapon).
    \90\ See, e.g., United States v. Wick, 697 F. App'x 507, 508 
(9th Cir. 2017) (complete Uzi parts kits ``could `readily be 
converted to expel a projectile by the action of an explosive,' thus 
meeting the statute's definition of firearm'' because the ``kits 
contained all of the necessary components to assemble a fully 
functioning firearm with relative ease''); United States v. Stewart, 
451 F.3d 1071, 1073 n.2 (9th Cir. 2006) (upholding district court's 
finding that .50 caliber rifle kits with incomplete receivers were 
``firearms'' under section 921(a)(3)(A) because they could easily be 
converted to expel a projectile).
---------------------------------------------------------------------------

    A ``weapon'' is defined by common dictionaries as ``[a]n instrument 
of offensive or defensive combat,'' see Webster's Third New 
International Dictionary 2589 (2002), but there is no requirement in 
either the dictionary definition or section 921(a)(3)(A) that the 
instrument have a minimum level of utility or lethality to be 
considered a ``weapon.'' \91\ While the aggregation of parts in a kit 
may not yet function as a weapon, these parts, simply in broken down 
form, can only be completed and assembled as instruments that expel 
live ammunition. Weapons completed from the parts in these kits 
typically incorporate or accept magazines that hold multiple rounds of 
lethal ammunition. They are not ornaments,\92\ toys,\93\ or industrial 
tools.\94\ Requiring some minimum level of utility, lethality, or 
actual functionality for aggregations of parts that are clearly 
identifiable as unassembled, unfinished, or incomplete pistols, 
revolvers, rifles, or shotguns, would be reading a requirement into the 
statutory definition of ``firearm'' that is not present. So long as the 
aggregation of parts is clearly identifiable as an instrument to expel 
live ammunition (including a starter gun), that is sufficient under 
section 921(a)(3)(A) to constitute a ``weapon.'' \95\ Indeed, numerous 
courts have recognized that an item was a rifle, shotgun, pistol, or 
revolver--a weapon--even though it was unassembled or nonfunctional due 
to missing or broken components.\96\
---------------------------------------------------------------------------

    \91\ See Bond v. U.S., 572 U.S. 844, 861 (2014) (citing 
dictionary definitions, and concluding that non-lethal irritant 
chemical was not a weapon).
    \92\ See, e.g., United States v. Wada, 323 F. Supp. 2d 1079, 
1081 (D. Or. 2004) (ornaments that ``would take a great deal of 
time, expertise, equipment, and materials to attempt to reactivate'' 
were no longer firearms).
    \93\ See, e.g., Lunde Arms Corp. v. Stanford, 107 F. Supp. 450, 
452 (S.D. Cal. 1952), aff'd, 211 F.2d 464 (9th Cir. 1954) (small 
muzzle loading toy cap gun that expelled non-lethal bird shot was 
not a ``weapon''); Rev. Rul. 54-519, 1954-2 C.B. 438 (inexpensive 
plastic toy gun was not a ``weapon'').
    \94\ See H.R. Rep. No. 90-1577, at 10 (June 21, 1968) 
(``[P]owder actuated industrial tools used for their intended 
purpose are not considered weapons and, therefore, are not included 
in this definition.''); S. Rep. No. 90-1097, at 111 (April 29, 1968) 
(same).
    \95\ Cf. United States v. Thompson/Center Arms, 504 U.S. 505, 
513, n.6 (1992) (finding that a rifle--a type of weapon--was 
``made'' under the NFA when a pistol was packaged together with a 
disassembled rifle parts kit even in the absence of ``combination of 
parts'' language); United States v. Hunter, 843 F. Supp. 235, 256 
(E.D. Mich. 1994) (``If Defendants believe that conversion kits are 
not in and of themselves `weapons' under Sec.  921(a)(3), they 
forget that that section clearly envisions machineguns as 
weapons.''); United States v. Drasen, 845 F.2d 731, 736-37 (7th Cir. 
1988) (rejecting argument that a collection of rifle parts cannot be 
a ``weapon'' even in the absence of combination of parts language); 
United States v. Grimm, 51 M.J. 254, 254 (C.A.A.F. 1999) 
(disassembled pistol with various components carried in different 
pants pockets was a ``weapon'').
    \96\ See footnotes 42 and 43, supra.
---------------------------------------------------------------------------

    The Department agrees with commenters that the term ``weapon which 
. . . may readily be converted to'' was inserted into the definition of 
``firearm'' in the GCA to include, as an example, starter guns designed 
for use with blank ammunition.\97\ However, the legislative history 
indicates that Congress included these guns because the convertibility 
of these starter pistols was found to be a matter of serious concern to 
law enforcement. One example of these conversions cited in the 
legislative history of the GCA was a ``do-it-yourself gunsmith'' who 
made out-of-State bulk purchases of starter pistols. ``[H]e would then, 
at his residence, disassemble them, and using an electric hand drill 
mounted in a drill press stand, bore out the plugged barrel and enlarge 
the cylinder chambers to accommodate .22-caliber cartridges.'' \98\

[[Page 24685]]

The focus on starter pistols is not on starter pistols themselves as a 
weapon, but on their ability to be converted to a functional state. As 
such, the Department sees no legal distinction under the GCA between 
starter guns that may readily be converted to fire, and pistols, 
revolvers, rifles, or shotguns parts kits that may readily be converted 
to fire. All are incomplete ``weapons'' that may readily be converted 
to fire under the GCA.
---------------------------------------------------------------------------

    \97\ See S. Rep. No. 89-1866, at 14, 73 (Oct. 19, 1966) (``Added 
to the term `firearm' are weapons which `may be readily converted 
to' a firearm. The purpose of this addition is to include 
specifically any starter gun designed for use with blank ammunition 
which will or which may be readily converted to expel a projectile 
or projectiles by the action of an explosive.'').
    \98\ See S. Rep. No. 88-1340, at 14 (Aug. 7, 1967). The 
completed weapons were reassembled, packaged as a kit with a holster 
and a box of fifty .22-caliber cartridges, and sold to youth gang 
members.
---------------------------------------------------------------------------

    Determining when a weapon configured as a parts kit meets the 
statutory definition of ``firearm'' requires a case-by-case evaluation 
of each kit. Some weapon parts kits are ``firearms'' because they are 
designed to expel a bullet, even if they cannot presently fire or 
readily be made to function because of damage, poor workmanship, or 
design flaw or feature.\99\ Such weapon parts kits are akin to 
``unserviceable firearms,'' defined by the GCA as ``a firearm which is 
incapable of discharging a shot by means of an explosive and incapable 
of being readily restored to a firing condition'' (emphases 
added).\100\ Some weapon parts kits are ``firearms'' because they may 
readily be converted to expel a bullet, even if they cannot yet expel 
one or function without additional work.
---------------------------------------------------------------------------

    \99\ The common meaning of the term ``design'' is ``to conceive 
and plan out in the mind'' or ``to plan or have in mind as a 
purpose.'' See United States v. Gravel, 645 F.3d 549, 551 (2d Cir. 
2011) (quoting Webster's Third Int'l Dictionary (1993)).
    \100\ Section 201 of Public Law 90-618 (Title II); 26 U.S.C 
5845(h); 27 CFR 478.11, 479.11 (definition of ``unserviceable 
firearm''); H.R. Rep. No. 90-1577, at 10 (June 21, 1968) (``This 
provision makes it clear that so-called unserviceable firearms come 
within the definition.''); S. Rep. No. 90-1097, at 111 (April 29, 
1968) (same). The GCA allows an unserviceable curio or relic firearm 
other than a machinegun to be imported. 18 U.S.C. 925(d)(2). 
Unserviceable NFA firearms may also be transferred as a curio or 
ornament without payment of the transfer tax. 26 U.S.C. 5852(e).
---------------------------------------------------------------------------

    The Department disagrees with the comment that weapon parts kits 
must contain all component parts of the weapon to be ``readily'' 
converted to expel a projectile. But the Department agrees that the 
completeness of the kit is an important factor in determining whether a 
weapon parts kit may readily be converted to expel a projectile. This 
is why one of the factors in the definition of ``readily'' that courts 
have relied upon in determining whether a weapon may ``readily be 
restored'' to fire is whether additional parts are required, and how 
easily they may be obtained. An essential part missing from the kit 
that cannot efficiently, quickly, and easily be obtained would mean 
that the weapon cannot readily be completed, assembled, restored, or 
otherwise ``converted'' to a functional state.\101\
---------------------------------------------------------------------------

    \101\ As explained in the next section, the Department also 
disagrees that the terms ``assembled'' and ``completed'' cannot be 
equated with ``conversion'' because that latter term means, in the 
context of manufacturing, altering raw materials to make them 
suitable for use. See footnote 104, infra.
---------------------------------------------------------------------------

d. Lack of Authority To Regulate ``Partially Complete'' Frames or 
Receivers
Comments Received
    Commenters argued that ATF does not have authority to regulate 
``partially complete frames or receivers'' because section 921(a)(3)(B) 
is clear that a completed frame or receiver is not a weapon, but only a 
part of such a weapon. Their theory is that if a frame or receiver were 
equivalent to a weapon, then section 921(a)(3)(B) would be read as 
``the weapon of any such weapon'' rather than ``the frame or receiver 
of any such weapon.'' Further, commenters stated that ATF does not have 
authority to apply the phrase ``may readily be converted'' to define 
``partially complete . . . frame or receiver'' since the ``may readily 
be converted'' language was included in prong (A) of section 921(a)(3) 
(applying to weapons) but not prong (B), meaning that ``readily'' 
cannot be applied to ``frame or receiver'' to allow for the inclusion 
of partially complete frames or receivers in the regulatory scheme.
Department Response
    The Department agrees with commenters who stated that frames or 
receivers are not ``weapons.'' They are the frames or receivers ``of'' 
the weapons described in 18 U.S.C. 921(a)(3)(A), and they are regulated 
as ``firearms'' with or without the component parts necessary to 
produce complete weapons. 18 U.S.C. 921(a)(3)(B). But Congress did not 
define the term ``frame or receiver'' in 18 U.S.C. 921(a)(3)(B), and 
the crucial inquiry is at what point an unregulated piece of metal, 
plastic, or other material becomes a ``frame or receiver'' that is a 
regulated item under Federal law. ATF has long held that a piece of 
metal, plastic, or other material becomes a frame or receiver when it 
has reached a ``critical stage of manufacture.'' To make this 
determination, ATF's position has been that the item has reached a 
``critical stage of manufacture'' when it is ``brought to a stage of 
completeness that will allow it to accept the firearm components to 
which it is designed for [sic], using basic tools in a reasonable 
amount of time.'' \102\ Accordingly, this rule explains that the terms 
``frame'' and ``receiver'' include a partially complete frame or 
receiver ``that is designed to, or may readily be completed, assembled, 
restored, or otherwise converted'' to accept the parts it is intended 
to house or hold.
---------------------------------------------------------------------------

    \102\ See ATF Letter to Private Counsel #303304, at 3-4 (Mar. 
20, 2015) (internal quotation marks omitted); ATF Rul. 2015-1 (an 
AR-type lower receiver that has been indexed may be classified as a 
receiver even though additional machining or other manufacturing 
process takes place to remove material from the cavity that allows 
the fire control components to be installed).
---------------------------------------------------------------------------

    The Department disagrees with commenters' suggestion that the 
Department cannot use the concepts of ``readily'' and ``converted'' in 
describing partially complete frames and receivers simply because those 
terms appear in section 921(a)(3)(A). In crafting the language of the 
regulation, ATF has properly considered concepts concerning when other 
firearms reach the point at which they are regulated under Federal 
law.\103\ This analysis is also appropriate because the very definition 
of ``manufacturing'' is the process of ``converting'' raw materials 
into finished goods suitable for use.\104\
---------------------------------------------------------------------------

    \103\ See footnotes 43 and 44, supra; see also 18 U.S.C. 
921(a)(3)(A); 26 U.S.C. 5845(b).
    \104\ See Merriam-Webster.com, available at https://www.merriam-webster.com/dictionary/convert (last visited Mar. 24, 2022) (The 
term ``convert'' means ``to alter the physical or chemical nature or 
properties of especially in manufacturing.''); Samsung Electronics 
Co., Ltd. v. Apple Inc., 137 S. Ct. 429, 435 (2016) (`` 
`manufacture' means `the conversion of raw materials by the hand, or 
by machinery, into articles suitable for the use of man' and `the 
articles so made.' '' (citing J. Stormonth, A Dictionary of the 
English Language at 589 (1885))); FastShip, LLC v. United States, 
892 F.3d 1298, 1303 n.7 (Fed. Cir. 2018) (same); Cyrix Corp. v. 
Intel Corp., 803 F. Supp. 1200, 1206 (E.D. Tex. 1992) (referring to 
the manufacturing process of converting raw materials into computer 
coprocessors); Swiss Manufacturers Ass'n, Inc. v. United States, 39 
Cust. Ct. 227, 233 (1957) (``What must be kept in mind is the 
distinction between manufacturing operations which advance the 
materials as materials and manufacturing operations which convert 
the materials into the complete articles.''); Dean & Sherk Co., Inc. 
v. United States, 28 Cust. Ct. 186, 189 (1952) (``It may require 
more than one manufacturing process to convert a textile material 
into a new textile material having a new name, character, or 
use.''); United States v. J.A. Schneider & Co., 21 C.C.P.A. 352, 357 
(Cust. & Pat. App. 1934) (referring to the process of taking 
finished products of certain processes of manufacture as ``material 
for subsequent manufacturing processes necessary to convert them 
into parts for furniture''); Bedford Mills v. United States, 75 Ct. 
Cl. 412, 423 (1932) (referring to a ``manufacturer'' as ``one who 
converts raw materials into a finished product''); Stoneco, Inc. v. 
Limbach, 53 Ohio St. 3d 170, 173, 560 N.E. 2d 578, 580 (Ohio. 1990) 
(``manufacturing is the commercial use of engines, machinery, tools, 
and implements to convert material into a new form, quality, 
property, or combination and into a more valuable commodity for 
sale''); State v. American Sugar Refining Co., 108 La. 603, 627, 32 
So. 965, 974 (La. 1902) (``The process of manufacture converts the 
raw material . . . into the manufactured articles''); see also Prod. 
Liab.: Design and Mfg. Defects Sec.  14:7 (2d ed.) (``The basic 
function of the manufacturing organization is to convert raw 
materials into finished products.''); cf. Broughman v. Carver, 624 
F.3d 670, 675 (4th Cir. 2010) (to ``manufacture'' a firearm means 
``to render the firearm `suitable for use' '').

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[[Page 24686]]

    While this analysis is intended to capture when an item becomes a 
frame or receiver that is regulated irrespective of the type of 
technology used, unformed blocks of metal, liquid polymers, and other 
raw materials only in a primordial state would not be considered by 
this rule to be a frame or receiver. However, when a frame or receiver 
is broken, disassembled into pieces, or is a forging, casting, or 
additive printing for a frame or receiver (i.e., a partially complete 
frame or receiver) that has reached a stage of manufacture where it can 
readily be completed, assembled, restored, or otherwise converted into 
a functional frame or receiver, that article is a ``frame or receiver'' 
under the GCA.\105\
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    \105\ See S. Rep. No. 90-1501, at 46 (Sept. 6, 1968) (``Of 
course, if the frame or receiver are themselves unserviceable as a 
frame or receiver then they would be treated as an unserviceable 
machinegun. Any machinegun frame or receiver which is readily 
restorable would be treated as serviceable.''); United States v. 
Thomas, No. 17-194 (RDM), 2019 WL 4095569, at *5 (D.D.C. Aug. 29, 
2019) (In holding that a revolver missing its trigger, hammer, and 
cylinder pin was a ``frame or receiver'' under section 921(a)(3)(B), 
the Court stated that ``Thomas's theory also twists the statutory 
definition beyond comprehension: Under his theory, Congress included 
the `frame or receiver' of a weapon--which is, by definition, 
inoperable--in the statutory definition, but did so only for those 
frames or receivers that are part of an operable weapon. The Court 
rejects this mind-bending reading of the statute.'').
---------------------------------------------------------------------------

    In light of the widespread availability of unlicensed and 
unregulated partially complete or unassembled frames or receivers, 
which are often sold as part of easy-to-complete kits, it is necessary 
to deter prohibited persons from obtaining or producing firearms by 
clarifying that incomplete frames or receivers can be firearms within 
the meaning of the governing law.\106\ Otherwise, persons could easily 
circumvent the requirements of the GCA and NFA, including licensing, 
marking, recordkeeping, and background checks (and, if a machinegun, 
NFA registration) simply by producing almost-complete frames or 
receivers, or by making a few minor alterations to existing frames or 
receivers that could quickly be altered to produce either a functional 
weapon, or a functional frame or receiver of any such weapon. To be 
sure, many prohibited persons have easily obtained them.\107\ A 
contrary rule, under which prohibited persons can easily make or 
acquire virtually untraceable firearms directly from unlicensed parts 
manufacturers, would unreasonably thwart Congress's evident purpose in 
the GCA and the NFA.\108\ These principles provide further reason not 
to read into the definition of ``frame or receiver'' terms like 
``finished,'' ``operable,'' ``functional,'' or a minimum percentage of 
completeness (e.g., ``80.1%'').
---------------------------------------------------------------------------

    \106\ The Polymer 80 assembly, for example, may be completed in 
under thirty minutes. See, e.g., Silverback Reviews, POLYMER 80 
Lower completion/Parts kit install, YouTube (Aug. 19, 2019), 
available at https://web.archive.org/web/20200331211935/https://www.youtube.com/watch?v=ThzFOIYZgIg (21-minute video of completion 
of a Polymer 80 lower parts kit with no slide) (last visited Apr. 1, 
2022). Indeed, the internet is replete with ``numerous videos that 
provide explicit instructions on how to construct ghost guns.'' 
Letter for Susan Wojcicki, CEO, YouTube, from Senators Blumenthal, 
Menendez, Murphy, Booker, and Markey at 1 (Feb. 14, 2022), available 
at https://www.blumenthal.senate.gov/imo/media/doc/0215.22youtubeghostguns.pdf (last visited Apr. 1, 2022); Joshua 
Eaton, Senators call on YouTube to crack down on `ghost gun' videos, 
NBCNews.com (Feb. 15, 2022), available at https://www.nbcnews.com/news/us-news/senators-youtube-ghost-gun-videos-rcna16387 (last 
visited Apr. 1, 2022); Joshua Eaton, YouTube banned `ghost gun' 
videos. They're still up., NBCNews.com (Dec. 9, 2021), available at 
https://www.nbcnews.com/news/us-news/youtube-ghost-gun-videos-rcna7605 (last visited Apr. 1, 2022).
    \107\ See footnote 20, supra; see also Convicted Felon Nabbed in 
Lakeside with Meth, Ghost Guns and Burglary Tools, 
timesofsandiego.com (Jan. 29, 2022), available at https://timesofsandiego.com/crime/2022/01/29/convicted-felon-nabbed-in-lakeside-with-meth-ghost-guns-and-burglary-tools/ (last visited Mar. 
24, 2022); Kym Kemp, Felon found with `ghost gun' arrested, says 
HCSO, kymkemp.com (Nov. 29, 2021), available at https://kymkemp.com/2021/11/29/felon-found-with-ghost-gun-arrested-says-hcso/ (last 
visited Mar. 24, 2022); Det. Patrick Michaud, Georgetown Arrest of a 
Felon Leads to Recovery of Ghost Gun, spdblotter.seattle.gov (Nov. 
8, 2021), available at https://spdblotter.seattle.gov/2021/11/08/georgetown-arrest-of-a-felon-leads-to-recovery-of-ghost-gun/ (last 
visited Mar. 24, 2022); Deputy recovers 'ghost gun' from convicted 
felon during traffic stop, fontanaheraldnews.com (Aug. 10, 2021), 
available at https://www.fontanaheraldnews.com/news/inland_empire_news/deputy-recovers-ghost-gun-from-convicted-felon-during-traffic-stop/article_3cfe0fd0-f4a3-11eb-bd31-03979dc83307.html (last visited Mar. 24, 2022); Lehigh Valley felon 
was using 3D printer to make `ghost guns' at home, Pa. attorney 
general says, lehighvalleylive.com (Jun. 29, 2021), available at 
https://www.lehighvalleylive.com/northampton-county/2021/06/lehigh-valley-felon-was-using-3d-printer-to-make-ghost-guns-at-home-pa-attorney-general-says.html (last visited Mar. 24, 2022); Press 
Release, Department of Justice, U.S. Attorney's Office, District of 
Conn., Bridgeport Felon Sentenced to More Than 5 Years in Federal 
Prison for Possessing Firearms (Jan. 7, 2021), https://www.justice.gov/usao-ct/pr/bridgeport-felon-sentenced-more-5-years-federal-prison-possessing-firearms; Christopher Gavin, Winthrop man 
had homemade `ghost' guns and 3,000 rounds of ammunition, 
prosecutors say, Boston.com (Aug. 5, 2020), available at https://www.boston.com/news/crime/2020/08/05/winthrop-man-had-homemade-ghost-guns-prosecutors-say (last visited Mar. 24, 2022); `Ghost Gun' 
used in shooting that killed two outside Snyder County restaurant, 
pennlive.com (Jul. 14, 2020), available at https://www.pennlive.com/crime/2020/07/ghost-gun-used-in-shooting-that-killed-two-outside-snyder-county-restaurant.html (last visited Mar. 24, 2022); The 
gunman in the Saugus High School shooting used a `ghost gun,' 
sheriff says, CNN.com (Nov. 21, 2019), available at https://www.cnn.com/2019/11/21/us/saugus-shooting-ghost-gun/index.html (last 
visited Mar. 24, 2022); How the felon killed at Walmart got his 
handgun, DA says, LehighValleyLive.com (March 9, 2018), available at 
https://www.lehighvalleylive.com/news/2018/05/how_the_felon_killed_at_walmar.html (last visited Mar. 24, 
2022);`Ghost guns': Loophole allows felons to legally buy gun parts 
online, KIRO7.com (Feb. 22, 2018), available at https://www.kiro7.com/news/local/ghost-guns-federal-loophole-allows-felons-to-legally-buy-gun-parts-online-build-assault-weapons/703695149/ 
(last visited Mar. 24, 2022).
    \108\ See New York v. Burger, 482 U.S. 691, 713 (1987) (``[T]he 
regulatory goals of the Gun Control Act . . . ensure[ ] that weapons 
[are] distributed through regular channels and in a traceable 
manner'' thus making ``possible the prevention of sales to 
undesirable customers and the detection of the origin of particular 
firearms.' '' (quoting United States v. Biswell, 406 U.S. 311, 315-
16 (1972))); City of Chicago v. U.S. Dep't of Treasury, Bureau of 
Alcohol, Tobacco & Firearms, 423 F.3d 777, 781 (7th Cir. 2005) 
(statutes should not be read in a way that ``would thwart Congress' 
intention'').
---------------------------------------------------------------------------

e. Lack of Authority To Regulate ``Privately Made Firearms''
Comments Received
    Commenters also generally stated that Congress did not grant any 
statutory authority to ATF to regulate PMFs. They explained that the 
GCA's central premise has been based on Congress's authority to 
regulate interstate commerce and that Congress has gone to great 
lengths to clarify that only those involved in commercial manufacturing 
are subject to the GCA. A private party, making a firearm for their own 
use, has never been subject to regulation. The commenter cited section 
101 of the GCA, which provides that ``it is not the purpose of this 
title to place any undue or unnecessary Federal restrictions or burdens 
on law-abiding citizens with the respect to the acquisition, 
possession, or use of firearms,'' and that the ``title is not intended 
to discourage the private ownership or use of firearms by law-abiding 
citizens.'' Commenters argue that because these PMFs are made solely 
for personal use, they do not come under the legal purview of the NFA 
or GCA as they lack any substantial connection to interstate commerce 
and therefore ATF is without statutory authority to make any rule 
pertaining to PMFs.
Department Response
    The Department agrees that firearms privately made by non-
prohibited persons solely for personal use generally do not come under 
the purview of the GCA.\109\ This rule does not restrict law-

[[Page 24687]]

abiding citizens' ability to make their own firearms from parts for 
self-defense or other lawful purposes. Under this rule, non-prohibited 
persons may continue to lawfully complete, assemble, and transfer 
unmarked firearms without a license as long as they are not engaged in 
the business of manufacturing, importing, dealing in, or transacting 
curio or relic firearms in a manner requiring a license. See 18 U.S.C. 
922(a)(1), 923(a), (b). Neither the GCA nor this implementing rule 
requires unlicensed individuals to mark (non-NFA) firearms they make 
for their personal use, or to transfer them to an FFL for marking. Such 
individuals who wish to produce, acquire, or transfer PMFs should, 
however, determine whether there are any applicable restrictions under 
State or local law.\110\
---------------------------------------------------------------------------

    \109\ However, the Undetectable Firearms Act of 1988, see 18 
U.S.C. 922(p), which amended the GCA, prohibits the manufacture and 
possession of any firearm that is not as detectable as the 
``Security Exemplar'' that contains 3.7 ounces of material type 17-4 
PH stainless steel.
    \110\ See footnote 24, supra; 18 U.S.C. 927.
---------------------------------------------------------------------------

    The Department disagrees with comments stating that ATF does not 
have the authority to regulate PMFs when those firearms are received 
and transferred by FFLs like other firearms subject to regulation under 
the GCA. The GCA provides that all firearms received and transferred by 
FFLs must be traceable through licensee records maintained for the 
period and in such form as prescribed by regulations. 18 U.S.C. 
923(g)(1)(A), (g)(2). There is no exception for PMFs.
f. Lack of Authority To Require FFLs To Mark Serial Numbers on 
``Privately Made Firearms''
Comments Received
    Several commenters stated that ATF lacks the statutory authority to 
require FFL dealers to engrave serial numbers on PMFs. Commenters 
argued that section 923(i) of the GCA only requires that ``licensed 
importers and licensed manufacturers'' mark firearms. They pointed out 
that while numerous provisions apply to importers, manufacturers, 
dealers, and collectors, not all do. For example, licensed collectors 
are not required to maintain records of importation as they are not 
listed in the statute. Accordingly, the commenters argued that Congress 
expressly imposed the duty to engrave serial numbers only on licensed 
importers and manufacturers but not on licensed dealers and that ATF is 
without any statutory basis to require any other FFLs, such as 
retailers, to mark firearms. Further, commenters argued that while the 
GCA requires a firearm have ``a serial number engraved or cast on the 
receiver or the frame of the weapon,'' this does not provide authority 
for ATF to require placement of multiple serial numbers or a single 
serial number on multiple parts.
Department Response
    The Department disagrees that, under the GCA, licensees other than 
licensed manufacturers and importers cannot be required to mark 
firearms. The Attorney General and ATF have authority to promulgate 
regulations necessary to enforce the provisions of the GCA, and 
requiring licensees to mark PMFs is such a regulation. See 18 U.S.C. 
926(a); H.R. Rep. No. 90-1577, at 18 (June 21, 1968); S. Rep. No. 90-
1501, at 39 (Sept. 6, 1968). ``Because Sec.  926 authorizes the 
[Attorney General] to promulgate those regulations which are 
`necessary,' it almost inevitably confers some measure of discretion to 
determine what regulations are in fact `necessary.' '' Nat'l Rifle 
Ass'n v. Brady, 914 F.2d 475, 479 (4th Cir. 1990). ``[T]he regulatory 
goals of the Gun Control Act . . . ensure[ ] that weapons [are] 
distributed through regular channels and in a traceable manner,'' thus 
making ``possible the prevention of sales to undesirable customers and 
the detection of the origin of particular firearms.' '' New York v. 
Burger, 482 U.S. 691, 713 (1987) (quoting United States v. Biswell, 406 
U.S. 311, 315-16 (1972)). ``Severely limiting the application of the 
GCA's `manufacturing' provisions would be inconsistent with these goals 
and would serve to `undermine the congressional policies' underlying 
the Act.'' Broughman v. Carver, 624 F.3d 670, 677 (4th Cir. 2010).
    In enacting the GCA, which amended the NFA, Congress clearly 
understood that persons other than licensed manufacturers and importers 
may need to mark firearms they make or possess privately with a serial 
number and other identifying information. See, e.g., 26 U.S.C. 5842(a)-
(b) (requiring unlicensed makers and possessors to place serial numbers 
and other marks of identification on NFA firearms as may be prescribed 
by regulations).\111\ The GCA requires licensees to record firearm 
information for purposes of tracing. Yet licensees have no serial 
number or other identifying information marked on the frame or receiver 
of a privately made (non-NFA) firearm that they can record in cases 
where a licensed manufacturer does not produce the firearm or an 
importer does not import the firearm, unless they are able to mark such 
firearms when received into inventory. Under 18 U.S.C. 923(i), licensed 
importers and manufacturers are required to mark firearms, but it does 
not prohibit others from also doing so. The GCA's silence on the 
specific manner in which licensees are to mark the firearms that they 
receive into inventory cannot be construed as a prohibition against any 
marking requirement through regulation.
---------------------------------------------------------------------------

    \111\ The Department also notes that 18 U.S.C. 922(k), which 
prohibits possession of a firearm with the ``importer's or 
manufacturer's serial number'' removed, obliterated, or altered, 
does not necessarily refer to the serial number placed by a licensed 
importer or a licensed manufacturer.
---------------------------------------------------------------------------

    This rule is necessary to ensure the continuing fulfillment of the 
congressional intent to mark and allow for tracing of all firearms. If 
licensees accept PMFs into their inventories with no identifying 
markings, then the required records they maintain would be rendered 
meaningless because there would be almost no information--only the 
``type'' of firearm--recorded in the A&D records, ATF Forms 4473, 
Theft/Loss Reports, and Reports of Multiple Sales. The information in 
these records is essential to public safety in that they are used to 
trace firearms involved in a crime and to prevent straw purchasers from 
acquiring them. There would be little point inspecting the records of 
FFLs that do not contain serial numbers, which are critical to solving 
and preventing crime.
    In this regard, 18 U.S.C. 923(g)(1)(A) and (g)(2) specifically 
authorize ATF to prescribe regulations with respect to the records 
regarding importation, production, shipment, receipt, sale, or other 
disposition of firearms. By regulation, a firearm's serial number and 
other identifying information are required to be entered on all Forms 
4473, A&D records, and ATF Forms 6/6A import permit applications. See 
27 CFR 478.112(b)(1)(iv)(G), 478.113(b)(1)(iv)(G), 478.114(a)(1)(v)(G), 
478.122(a)-(b), 478.123(a)-(b), 478.124(c)(4), 478.125(e), 
478.125a(a)(4). Licensees are also required to submit theft/loss 
reports and ATF Forms 3310.11 (pursuant to 18 U.S.C. 923(g)(6)), and 
multiple sales and demand letter transaction reports, ATF Forms 3310.4, 
3310.12, and 5300.5 (pursuant to 18 U.S.C. 923(g)(3)(A) and (g)(5)(A)), 
all of which require reporting of the serial number and other 
identifying information. As explained in this rule, these records and 
reports are largely meaningless without a unique identifying number and 
associated licensee information. Therefore, in order for licensees to 
comply with recording and reporting this information as required, it is 
incumbent on them to serialize--or cause to be serialized--all firearms 
that are taken into their inventories.

[[Page 24688]]

    At the time the GCA was enacted, almost all firearms were 
commercially produced by manufacturers (either within or outside the 
U.S.) because the milling equipment, materials needed, and designs were 
far too expensive for individuals to make firearms practically or 
reliably on their own. But today, firearms may be made at home from 
commercially produced parts kits by purchasing individual parts or 
using personally owned or leased equipment, including 3D printers. 
Also, cheaper materials, such as polymer plastics, along with 
blueprints and instructions, are now readily available over the 
internet. When Congress enacted the GCA, it likely did not consider 
that unmarked PMFs would enter the business or collection inventories 
of licensees, at least not in any significant number. ``But whatever 
the reason, the scarcity of controls in the secondary market provides 
no reason to gut the robust measures Congress enacted at the point of 
sale.'' Abramski v. United States, 573 U.S. 169, 187 (2014).
    Further, the rule necessarily allows licensed firearms dealers, 
including gunsmiths, to mark PMFs because licensed manufacturers and 
importers may refuse to provide these services as they are generally 
focused on their own production or importation of firearms. Without 
this change, the availability of professional marking by dealer-
gunsmiths would be greatly limited and the efficacy of the rule would 
also be reduced if unlicensed individuals had fewer options to have 
their PMFs professionally marked. Moreover, allowing licensed firearms 
dealers, or licensed or unlicensed persons under the direct supervision 
of licensed firearms dealers, to properly mark firearms in a manner 
that ATF can trace directly to them reduces the tracing burden on 
manufacturers and importers, as well as law enforcement. It also 
provides dealers with the opportunity to earn additional income from 
repairing, customizing, or pawning firearms that are privately made--
firearms that are highly likely to proliferate throughout the 
marketplace over time as firearms production technology develops. 
Licensed dealer-gunsmiths, in particular, are well-equipped to provide 
these services as they routinely engage in the business of engraving, 
painting, camouflaging, or otherwise customizing firearms for 
unlicensed individuals.\112\
---------------------------------------------------------------------------

    \112\ See ATF Rul. 2009-1. While this ruling explains that 
gunsmiths who engage in the business of camouflaging or engraving 
firearms must be licensed as dealers, that ruling is superseded by 
this rule to the extent that those processes are performed on 
firearms ``for purposes of sale or distribution,'' requiring a 
license as a manufacturer. See 18 U.S.C. 921(a)(10), (a)(21)(A), 
923(a). To address concerns and reduce the burden on licensed 
gunsmiths required to be re-licensed as manufacturers, this final 
rule expressly authorizes licensed manufacturers to adopt the 
existing markings on firearms unless they have been sold or 
distributed to a person other than a licensee. Additionally, the 
final rule clarifies that licensed manufacturers and importers, who 
are permitted to act as licensed dealers without obtaining a 
separate dealer's license, can conduct same-day adjustments or 
repairs on firearms without recording an acquisition provided the 
firearm is returned to the person from whom it was received. 
Further, this rule allows licensees who do not have engraving 
equipment to take a PMF to and directly supervise on-the-spot 
engraving of a serial number on the firearm by another licensee or 
even an unlicensed engraver so long as the dealer does not 
relinquish supervisory control over the firearm.
---------------------------------------------------------------------------

    Finally, the Department agrees with comments saying that the 
placement of multiple serial numbers on multiple frames or receivers of 
PMFs would be burdensome and costly for licensees, and would make it 
more difficult for law enforcement to trace firearms, including PMFs. 
For this reason, ATF is finalizing this rule to require placement of an 
individual serial number on a single frame or receiver of a given 
firearm. This does not mean, however, that it is impossible for a 
firearm to have more than one serial number marked on the frame or 
receiver. For example, a remanufacturer or importer who does not adopt 
an existing serial number as expressly allowed under this rule may re-
mark the firearm with their own unique serial number. This has always 
been the case under current regulations. Additionally, multi-piece 
frames or receivers as defined in this rule may have the serial number 
marked on different sides of the same frame or receiver. The Department 
nonetheless believes these circumstances are rare.
g. Violates the Administrative Procedure Act
Comments Received
    Numerous commenters objected to the NPRM on grounds that it is 
nothing more than a politically motivated rulemaking, demonstrated by 
ATF's use of a politicized nomenclature (i.e., ``ghost guns'') and 
reports that rulemaking was directed by certain lobbying groups. They 
further argued that the entire rule is arbitrary and capricious under 5 
U.S.C. 706(2)(A) of the Administrative Procedure Act (``APA'') because 
the agency relied on factors that Congress did not intend for it to 
consider. As an example, commenters stated that the definitions of 
``partially complete'' and ``split or modular frame or receiver'' rely 
on balancing tests that have no weighted or comprehensible standard and 
can create unfair surprise.
    Moreover, commenters argued the rule violates the APA because the 
proposed definitions are arbitrary and capricious and because they fail 
to account for the reliance interests of those affected by the action 
and fail to explain the agency's departure from prior policy. For 
example, commenters said that ATF's proposal to change serial marking 
requirements and the definition of ``gunsmith'' fails to provide any 
data or explanation as to how traces are failing under the current 
system due to existing marking requirements or why the definition for 
``gunsmith'' is suddenly changing after many years.
    Numerous commenters further argued that the rule, especially with 
respect to the proposed definition of ``frame or receiver'' to include 
partially completed frames or receivers, is arbitrary because the 
agency failed to address why it is deviating from its legal reasoning 
that it had made in recent past cases before Federal courts and on 
which the public relied. For example, commenters highlighted ATF's 
arguments presented in City of Syracuse v. ATF, 1:20-cv-06885, 2021 WL 
23326 (S.D.N.Y. Jan. 2, 2021), and California v. ATF, 3:20-cv-06761 
(N.D. Cal.). In ATF's Motion to Dismiss in California, the agency 
wrote: ``The longstanding position of ATF is that, where a block of 
metal (or other material) that may someday be manufactured into a 
receiver bears no markings that delineate where the fire-control cavity 
is to be formed and has not yet been even partially formed, that item 
is not yet a receiver and may not `readily be converted to expel a 
projectile.' '' Fed. Defs.' Mot. Dismiss, at 2, ECF No. 29 (Nov. 30, 
2020). One commenter pointed out that, in that same Motion to Dismiss, 
ATF stated that its refusal to classify unfinished lower receivers as 
firearms is based on concurring expertise from DOJ. Id. at 18-19 
(citing Shawn J. Nelson, Unfinished Lower Receivers, 63 U.S. Attorney's 
Bulletin No. 6 at 44-49 (Nov. 2015)). Similarly, commenters stated that 
ATF was clear in City of Syracuse that ``an unmachined frame or 
receiver is not `designed to' expel a projectile because its purpose is 
not to expel a projectile. Rather its purpose is to be incorporated 
into something else that is designed to expel a projectile.'' Mem. 
Supp. Fed. Defs.' Mot. Summ. J., at 21, ECF No. 98 (Jan. 29, 2021). 
Another commenter cited Police Automatic Weapons Services, Inc. v. 
Benson, 837 F. Supp. 1070 (D. Or. 1993), in which, before Congress 
ended the manufacture of machineguns for sale to ordinary persons, ATF 
had apparently refused to register incomplete machinegun

[[Page 24689]]

receivers because they were not complete enough to be considered a 
receiver. Similarly, one manufacturer stated that the rule's more 
expansive regulation governing frames or receivers would run counter to 
the legal reasoning ATF relied on in three prior classifications to the 
company dated February 2015, November 2015, and January 2017 regarding 
certain types of receiver blanks.
Department Response
    The Department disagrees that this rulemaking violates the APA or 
is an arbitrary or capricious reaction to the proliferation of ``ghost 
guns.'' This rule cites ATF statistics and media reports demonstrating 
the steady increase in the number of PMFs recovered from crime scenes 
(including homicides) throughout the country, and the small number of 
crime gun traces to an individual purchaser that were successful in 
relation to numerous attempted traces of PMFs (generally by tracing a 
serial number engraved on a handgun slide, barrel, or other firearm 
part not currently defined as a frame or receiver, but recorded by 
licensees in the absence of other markings). The NPRM and this rule 
cite numerous criminal cases brought by the Department against 
unlicensed persons who were engaged in the business of manufacturing 
and selling PMFs without a license, and prohibited persons found in 
possession of such weapons. This rule cites reports and studies showing 
that the problem of untraceable firearms being acquired and used by 
violent criminals and terrorists is international in scope. This rule 
details how unmarked firearms undermine the GCA's comprehensive 
regulatory scheme that requires licensing, marking, recordkeeping, and 
background checks for all firearms acquired and transferred by or 
through firearms licensees. This rule further explains how allowing 
persons to be licensed as dealer-gunsmiths will make professional 
marking services more available to unlicensed individuals, and make it 
possible for other licensees to receive and transfer PMFs should they 
choose to accept them into inventory in the course of their licensed 
activities. The Department carefully considered all commenters' 
concerns in finalizing this rule in accordance with the APA.
    The Department does not agree with commenters who said that the 
number of PMFs involved in crime should be compared with the number of 
all firearms involved in crime. At the outset, there is no threshold 
for establishing when law enforcement agencies may take steps to reduce 
violent crime. The subset of traces for PMFs is obviously fewer than 
those of commercially manufactured crime guns, which bear serial 
numbers and other identifying markings and make up a much greater 
volume of marked weapons in circulation, and firearms with serial 
numbers are much more likely to be traced successfully by law 
enforcement than PMFs without serial numbers. Regardless, with better 
and cheaper technologies, unmarked firearms are becoming more easily 
and repeatedly made by individuals using personally owned or leased 
equipment, including 3D printers. It is clear from this data that PMFs 
are increasingly being used in crime throughout the United States and 
internationally with no reason to believe the trend will not continue. 
Statistics concerning crime gun tracing of commercially manufactured 
firearms do not lessen the necessity of this rule to improve public 
safety in the context of unmarked PMFs.
    The Department disagrees with commenters who said that ATF is 
changing its position that a solid block of metal (or other material) 
that may someday be manufactured into a receiver that bears no markings 
that delineate where the fire-control cavity is to be formed, and has 
not yet been even partially formed, is not a ``receiver.'' Machining, 
indexing, or lack thereof, to the fire-control cavity remain an 
important factor in the readily completed, assembled, restored or 
otherwise converted analysis. To buttress this point, the final rule 
expressly excludes from the definitions of ``frame'' and ``receiver,'' 
``a forging, casting, printing, extrusion, unmachined body, or similar 
article that has not yet reached a stage of manufacture where it is 
clearly identifiable as an unfinished component part of a weapon (e.g., 
unformed block of metal, liquid polymer, or other raw material).'' In 
other words, an item in a primordial state, such as a solid block of 
metal, liquid polymer, raw material, or other item that is not clearly 
identifiable as a component part of a weapon, is not a ``frame'' or 
``receiver'' under this rule. This rule as proposed and finalized 
clarifies the distinction between a primordial object and a partially 
complete frame or receiver billet or blank that may be considered a 
``frame'' or ``receiver'' under certain circumstances.
    However, prior to this rule, ATF did not examine templates, jigs, 
molds, instructions, equipment, or marketing materials in determining 
whether partially complete frames or receivers were ``firearms'' under 
the GCA. For this reason, ATF issued some classifications concluding 
that certain partially complete frames or receivers were not ``frames 
or receivers'' as now defined in this rule. This change to allow 
consideration of templates, jigs, instructions, etc. in classification 
determinations does not run afoul of the APA. See F.C.C. v. Fox, 556 
U.S. 502, 517 (2009) (Federal Communications Commission did not act 
arbitrarily when it changed its policy regarding fleeting expletives). 
The Supreme Court ``fully recognize[s] that regulatory agencies do not 
establish rules of conduct to last forever and that an agency must be 
given ample latitude to adapt [its] rules and policies to the demands 
of changing circumstances.'' Motor Vehicle Manufacturer's Ass'n v. 
State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 41 (1983) (citation and 
internal quotation marks omitted). The aggregation of a template or jig 
with a partially complete frame or receiver, such as those included in 
firearm parts kits, can serve the same purpose as indexing, making an 
item that is clearly identifiable as a partially complete frame or 
receiver into a functional one efficiently, quickly, and easily (i.e., 
``readily''). Because indexing allows partially complete frames or 
receivers to be completed efficiently, quickly, and easily, such 
articles will now be considered frames or receivers under this rule. As 
stated in the NPRM and this final rule, changing circumstances--i.e., 
more advanced and accessible technology, the subsequent proliferation 
of ``80% receivers,'' and the resulting threat to public safety from 
unserialized firearms--necessitate this change.
    With regard to the comment on gunsmiths, the rule is necessary to 
explain who is required to be licensed as a gunsmith, as distinguished 
from a manufacturer. In addition to comments concerned with the 
application of the proposed definition, ATF has received numerous 
inquiries over the years asking whether persons are required to be 
licensed as dealer-gunsmiths (Type 01) or manufacturers (Type 07). See, 
e.g., ATF Ruls. 2009-1, 2009-2, 2010-10, and 2015-1. The current 
definition of ``engaged in the business'' in 18 U.S.C. 921(a)(21)(D) 
and ``gunsmith'' in 27 CFR 478.11 describe a gunsmith as a ``person who 
devotes time, attention, and labor to engaging in such activity as a 
regular course of trade or business with the principal objective of 
livelihood and profit'' without explaining the range of commercial 
activities gunsmiths perform, or when those activities can be performed 
on firearms for sale or distribution without a manufacturer's license. 
This rule,

[[Page 24690]]

therefore, necessarily clarifies the meaning of that term.
h. Violates the Prohibitions Against Creation of a Gun Registry
Comments Received
    Numerous commenters objected to the proposed serial marking 
requirements, claiming it is a ploy by the Government to subject law-
abiding gun owners who enjoy and have the right to build their own 
firearms to a rigorous registration requirement. They claimed that the 
requirement that PMFs be serialized only leads to an illegal gun 
registry, which ATF is forbidden from creating under Federal law. 
Commenters similarly opined that the extended recordkeeping requirement 
is a clear sign that ATF intends to have a registry of all firearms 
owners going far beyond those who are legally required to register 
firearms under the NFA.
Department Response
    The Department disagrees that this rule creates a registry of PMFs, 
for several reasons. First, neither the GCA nor this implementing rule 
requires unlicensed individuals to mark (non-NFA) firearms they make 
for their personal use, or when they occasionally acquire them for, or 
sell or transfer them from, a personal collection to unlicensed in-
State residents consistent with Federal, State, and local law. There 
are also no recordkeeping requirements imposed by the GCA or this rule 
upon unlicensed persons who make their own firearms, but only upon 
licensees who choose to take PMFs into inventory. And, under this final 
rule, when FFLs do choose to accept PMFs into inventory, and no 
manufacturer name has been identified on a PMF (if privately made in 
the United States), the words ``privately made firearm'' (or the 
abbreviation ``PMF'') are required to be recorded as the name of the 
manufacturer, not the name of the actual private maker.
    Second, records of production, acquisition, and disposition of all 
firearms are required by the GCA, 18 U.S.C. 923(g)(1)(A) and (g)(2), to 
be completed and maintained by FFLs at their licensed business premises 
for such period, and in such form, as the Attorney General may 
prescribe by regulations. In this rule, ATF is exercising that 
authority to change the manner and duration in which those records are 
maintained. At present, licensees are required to maintain their 
acquisition and disposition records for at least 20 years. This rule 
merely extends the 20-year retention period so that those records are 
not destroyed, and thus can be used for tracing purposes.
    Although ATF has the authority to inspect an FFL's records under 
certain conditions, see 18 U.S.C. 923(g)(1)(B)-(C), the records belong 
to and are maintained by the FFLs, not the government. Only after an 
FFL discontinues business does the GCA, 18 U.S.C. 923(g)(4), require 
FFLs to provide their records to ATF so that tracing of crime guns can 
continue.\113\ In fact, the provision cited by some commenters, 18 
U.S.C. 926(a), expressly provides that ``[n]othing in this section 
expands or restricts the Secretary's authority to inquire into the 
disposition of any firearm in the course of a criminal investigation.'' 
Moreover, Federal law has long prohibited ATF from consolidating or 
centralizing licensee records. Since 1979, congressional appropriations 
have prohibited ATF from using any funds or salaries for the 
consolidation or centralization of records of acquisition and 
disposition of firearms maintained by FFLs. See Treasury, Postal 
Service, and General Government Appropriations Act, 1980, Public Law 
96-74, 93 Stat. 559, 560 (1979). This annual restriction became 
permanent in 2011. See Public Law 112-55, 125 Stat. 632 (2011). Thus, 
ATF is already restricted by law from creating any such registry, and 
this rule does not create one.\114\
---------------------------------------------------------------------------

    \113\ The out-of-business firearms transaction records are 
indexed by abbreviated FFL number so that they may be accessed when 
needed to complete a firearm trace request involving a licensee that 
is no longer in business. Out-of-business firearms transaction 
records are not searchable by an individual's name or other personal 
identifiers. In 2006, ATF transitioned from using microfilm images 
of records to scanning records into a digital storage system with 
images that are not searchable through character recognition, 
consistent with ATF's design and use of its prior Microfilm 
Retrieval System. A 2016 GAO Audit (GAO-16-552) concluded that ATF's 
digital system complies with the restrictions prohibiting 
consolidation or centralization of FFL records. See also Statutory 
Federal Gun Registry Prohibitions and ATF Record Retention 
Requirements, Congressional Research Service (March 4, 2022), 
https://crsreports.congress.gov/product/pdf/IF/IF12057 (last visited 
Apr. 3, 2022).
    \114\ See 124 Cong. Rec. 16637 (June 7, 1978) (statement of Rep. 
Drinan) (``The most frequent criticism of the March 21 regulations 
is their alleged establishment of a `national gun registration' 
system. Is it possible to establish such a system under a set of 
regulations which prohibit the submission, collection, or 
maintenance on file of the identifies of owners and purchasers of 
firearms? Clearly, the answer is no. These regulations are not 
directed at gun purchasers; they are designed instead to aid law 
enforcement officers by requiring that firearms manufacturers and 
dealers keep track of firearms transactions. Put more simply, the 
regulations will trace guns, not gun owners. Individual purchasers 
of firearms will not have to register their weapons, and the Bureau 
will not establish a centralized registry of firearms owners.'').
---------------------------------------------------------------------------

i. Violates 18 U.S.C. 242 and 1918
Comments Received
    Out of concern regarding their rights under the Second Amendment to 
the U.S. Constitution, several commenters claimed that by working on 
this rule, ATF officials are violating 18 U.S.C. 242, which makes it a 
crime for a person acting under color of any law to willfully deprive a 
person of a right or privilege protected by the Constitution or laws of 
the United States. Commenters also claim that ATF officials and 
employees are likewise violating their oath of office to support and 
defend the U.S. Constitution (particularly the Second Amendment), which 
the commenters state is punishable under 18 U.S.C. 1918.
Department Response
    The Department disagrees that any official involved in promulgating 
or implementing this rule violates 18 U.S.C. 242 or 1918, or any other 
Federal law. As stated previously, this rule does not impact the Second 
Amendment rights of law-abiding citizens to keep and bear firearms for 
lawful personal use. The regulations proposed and finalized herein do 
not raise Second Amendment concerns because they are ``presumptively 
lawful regulatory measures'' that ``impos[e] conditions and 
qualifications on the commercial sale of arms.'' Heller, 554 U.S. at 
626-27 & n.26.
3. Concerns With Proposed Definitions
a. General Concerns With Proposed Definitions
Comments Received
    Numerous commenters stated that no changes to the regulations are 
needed because the current definitions are adequate. They also believe 
that ATF's private letter rulings are adequate communications to 
provide information to the industry and firearms owners. Commenters 
opposed to the proposed definitions and new terms in the NPRM stated 
that the new definitions, which they assert are vague, use terms and 
phrases that are even more unclear. For instance, commenters argued 
that although ``partially complete receiver'' is defined, the 
definition has even more vague, problematic terms such as ``clearly 
identifiable,'' ``unfinished component part of a weapon,'' ``critical 
stage of manufacture,'' ``sufficiently complete to function,'' and 
``primordial state.'' Similar to the due process and APA concerns 
discussed earlier, one major objection of commenters to the proposed 
definitions was that the definitions are too broad to be workable.

[[Page 24691]]

A majority of these comments focused on the supplemental definitions of 
``split or modular frame or receiver'' and ``partially complete, 
disassembled, or inoperable frame or receiver.''
    Several commenters stated that the very problem ATF is trying to 
solve is made worse by the proposed regulations, as no reasonable 
person would be able to determine which component or components of a 
given firearm constitute a frame or receiver. As summed up by some 
commenters: ``The proposed definition creates a reality where a 
reasonable person would be forced to assume that every component of the 
firearm which meets the proposed definition of firearm frame or 
receiver is such, unless they are aware of a determination to the 
contrary by ATF. Therefore, consumers must constantly be in doubt as to 
whether a firearm in their possession has been properly marked in 
accordance with the law, or if they are in possession of an illegal 
item.'' Moreover, as discussed in Section IV.B.13.b of this preamble, 
numerous commenters opined that the proposed definition of ``frame or 
receiver'' and its supplemental definitions, which would trigger new 
marking or recordkeeping requirements, would be cost prohibitive to the 
industry and to firearms owners.
Department Response
    The Department disagrees with commenters who stated that the 
current definitions are adequate. The NPRM and this final rule explain 
in detail how the current definitions of ``firearm frame or receiver'' 
and ``frame or receiver'' in 27 CFR 478.11 and 479.11 do not adequately 
describe the major component of split or modular weapons or muffler or 
silencer devices required to be identified and recorded by licensees as 
a ``firearm.'' The current definition describes a housing for three 
fire control components: Hammer, bolt or breechblock, and firing 
mechanism. But the vast majority of firearms in common use today do not 
have a single housing for all of those components, and numerous 
firearms today are not hammer-fired. They often have split frame or 
receiver designs, and many are striker-fired. As stated previously, 
three courts have already applied ATF's definition of ``frame or 
receiver'' in a way that would leave most firearms currently in 
circulation in the United States without an identifiable frame or 
receiver. See United States v. Rowold, 429 F. Supp. 3d 469, 475-76 
(N.D. Ohio 2019) (``The language of the regulatory definition in Sec.  
478.11 lends itself to only one interpretation: Namely, that under the 
GCA, the receiver of a firearm must be a single unit that holds three, 
not two components: (1) The hammer, (2) the bolt or breechblock, and 
(3) the firing mechanism.''); United States v. Roh, SACR 14-167-JVS, 
Minute Order p. 6 (C.D. Cal. July 27, 2020); United States v. Jimenez, 
191 F. Supp. 3d 1038, 1041 (N.D. Cal. 2016).
    The proposed new terms and definitions are also needed to explain 
when weapon parts kits, frame or receiver parts kits, and multi-piece 
frames or receivers are ``firearms'' and thus subject to regulation, 
and how licensees can accept unmarked PMFs into their inventories. The 
rule points out that silencer manufacturers are currently uncertain 
when and how each small silencer part must be marked given that each 
part is defined as a ``silencer'' under the law. Clarifying these 
issues in individual private letter rulings is not adequate to provide 
sufficient notice and guidance to the licensed community and public at 
large as to how firearms are defined and regulated. In addition, letter 
rulings are only applicable for the precise sample submitted to ATF, 
and those classifications may then be misapplied (as some have done) to 
other items that may appear similar, but have legally important 
differences. For these reasons, the Department has addressed these 
issues through this rulemaking to promulgate new definitions that apply 
to all existing firearm designs as well as to accommodate future 
changes in firearms technology and terminology.
    Nonetheless, the Department agrees with commenters that the 
supplement to the proposed definition of ``frame or receiver'' entitled 
``split or modular frame or receiver'' could have been costly to 
licensees to implement, and that the supplement ``partially complete, 
disassembled, or inoperable frame or receiver'' should be revised to 
provide more clarity on how it applies to the definition of ``frame or 
receiver.'' In response to comments, in the final rule the Department 
has removed the supplement entitled ``split or modular frame or 
receiver,'' made additions to explain how multi-piece frames or 
receivers must be identified, and made clarifying changes to the 
supplement entitled ``partially complete, disassembled, or inoperable 
frame or receiver.''
    Finally, although the Department disagrees that certain terms in 
this rule were vague, additional clarity has been provided to explain 
the meaning of those terms. Examples of articles that are ``clearly 
identifiable as an unfinished component part of a weapon'' are unformed 
blocks of metal, liquid polymers, and other raw materials. The 
dictionary definition of the term ``primordial'' was adopted and 
explained in footnote 49 of this preamble. The term ``sufficiently 
complete to function as a frame or receiver'' is no longer used in the 
regulatory text. That term was replaced with ``to function as a frame 
or receiver,'' which is described as ``to house or provide a structure 
for the primary energized component of a handgun, breech blocking or 
sealing component of a projectile weapon other than a handgun, or 
internal sound reduction component of a firearm muffler or firearm 
silencer, as the case may be.''
b. Definition of ``Firearm'' and Weapon Parts Kits
Comments Received
    In addition to stating that ATF does not have authority to include 
weapon parts kits in the definition of ``firearm,'' several commenters 
also stated the definition was flawed and would serve no purpose. For 
instance, commenters said it is futile to regulate a weapon parts kit 
because a kit could be sold without a firing pin and thus would not be 
in a state where it is readily completable, enabling kit manufacturers 
to circumvent the definition by selling the kit separately from a cheap 
and readily available pin. Other commenters stated that if ATF's 
definitions mean that a ``weapon parts kit'' containing all unregulated 
parts, including a so-called ``80% receiver,'' is a ``firearm,'' this 
would raise the question of whether a kit with a forging in a 
primordial state is still a firearm because the pieces taken together 
could expel a projectile by an action of an explosive even if it is not 
readily convertible for that purpose. They stated that under ATF's 
interpretation it appears to be irrelevant whether the part that could 
become the frame or receiver ``may readily be converted'' as long as it 
is ``designed to expel a projectile by action of an explosive.'' 
Separately, since the preamble described ``weapons parts kits'' as 
having ``most or all of the components,'' commenters questioned whether 
a kit that does not contain all of the necessary components to expel a 
projectile by the action of an explosive is still ``designed'' or 
``readily convertible'' to do so. Commenters thus sought more clarity 
on what components must be present in a kit to constitute a firearm.
Department Response
    The Department disagrees with commenters that including weapon 
parts kits in the definition of ``firearm''

[[Page 24692]]

serves no purpose. The GCA is clear that when a weapon will, is 
designed to, or may readily be converted to expel a projectile by the 
action of an explosive, the weapon is a ``firearm'' under 18 U.S.C. 
921(a)(3)(A). As explained above and in the NPRM, relevant case law 
makes clear that weapon parts kits that are designed to or may readily 
be assembled, completed, converted, or restored to expel a projectile 
by the action of an explosive qualify as a ``firearm'' under 18 U.S.C. 
921(a)(3)(A). See Section III.A, supra; 86 FR 27726 & nn.39-40. The 
rule thus amends the existing definition to explicitly note this 
application of the term ``firearm'' to include such weapon parts kits. 
The rule also relies on existing case law to provide a definition of 
the term ``readily'' and to detail the factors relevant to making that 
determination when classifying firearms. See Section III.C, supra; 
Section IV.B.3.j, infra. As earlier explained, in recent years, 
manufacturers and retailers have been selling to individuals weapon 
parts kits with incomplete frames or receivers, commonly called ``80% 
receivers,'' without conducting background checks or maintaining 
records. Some of these parts kits contain all of the necessary 
components (finished or unfinished), along with jigs, templates, or 
other tools that allow an individual to complete a functional weapon 
with minimal effort, expertise, or equipment within a short period of 
time.
    The Department disagrees with commenters who said that regulating 
weapon parts kits that were missing certain parts, such as a firing 
pin, would be futile. A weapon missing a firing pin is still a 
``firearm'' under section 921(a)(3)(A) because it is designed to expel 
a projectile.\115\ The fact that the same exact pistol without a firing 
pin has been disassembled into a parts kit does not alter the weapon's 
design. Moreover, one of the considerations in determining whether a 
weapon, including a weapon parts kit, may ``readily'' be converted to 
expel a projectile is whether additional parts are required, and how 
efficiently, quickly, and easily they can be obtained and assembled.
---------------------------------------------------------------------------

    \115\ See, e.g., United States v. Rivera, 415 F.3d 284, 285-87 
(2d Cir. 2005) (pistol with a broken firing pin and flattened 
firing-pin channel); United States. v. Brown, 117 F.3d 353, 356 (7th 
Cir. 1997) (gun with no firing pin); United States v. Hunter, 101 
F.3d 82, 85 (9th Cir. 1996) (pistol with broken firing pin); United 
States v. Yannott, 42 F.3d 999, 1005 (6th Cir. 1994) (shotgun with 
broken firing pin); United States v. York, 830 F.2d 885, 891 (8th 
Cir. 1987) (revolver with no firing pin and cylinder did not line up 
with barrel); United States v. Randolph, No. 02 CR. 850-01 (RWS), 
2003 WL 1461610, at *2 (S.D.N.Y. Mar. 20, 2003) (gun consisting of 
``disassembled parts with no ammunition, no magazine, and a broken 
firing pin'').
---------------------------------------------------------------------------

    The Department agrees that certain essential parts could be removed 
from the kit, potentially making it difficult to determine whether such 
a kit or aggregation of parts may readily be converted to fire. 
However, it would be impossible for the Department to set forth in the 
regulations a precise minimum percentage of completion, maximum time 
period, maximum level of expertise, or type or number of parts 
necessary to convert each and every make, model, and configuration of 
weapon parts kits now in existence, or that may be produced in the 
future. The Department believes that it is constitutionally, legally, 
and practically sufficient, and consistent with relevant case law, to 
explain in this rule that the conversion must be fairly or reasonably 
efficient, quick, and easy (though not necessarily the most efficient, 
speediest, or easiest process) after examining the enumerated factors. 
Additionally, if persons remain uncertain as to whether a particular 
weapon parts kit is a ``firearm,'' they may submit a voluntary request 
to ATF for a classification in accordance with this rule.
    While these determinations must necessarily be made on a case-by-
case basis, the Department believes that the term ``readily'' and the 
factors in this rule provide sufficient notice that certain weapon and 
frame or receiver parts kits are regulated under the GCA. It is not the 
purpose of the rule to provide guidance so that persons may structure 
transactions to avoid the requirements of the law. Persons who engage 
in the business of importing, manufacturing, or dealing in weapon and 
frame or receiver parts kits must be licensed, mark the frames or 
receivers within such kits with serial numbers and other marks of 
identification, conduct background checks, and maintain transaction 
records for them so that they can traced by law enforcement if involved 
in crime.
c. Definition of ``Frame or Receiver''
Comments Received
    Despite the grandfather provision ATF provided in the NPRM for 
existing frames or receivers, commenters said there is still confusion 
because one cannot examine the definition of ``frame or receiver'' to 
determine with any certainty whether a specific part of a firearm that 
was previously classified as a single frame or receiver is redefined as 
a split or modular frame or receiver and whether the entire scope of 
the definition is dependent upon the Director. Other commenters 
asserted that the definition of ``frame or receiver'' is vague because 
``almost any housing or structure that is at all visible from the 
exterior [is] susceptible to a classification as a frame or receiver'' 
or would make ``every single part of a firearm a `fire control 
component' '' such that firearms like the AR-15 may now include as many 
as ten frames or receivers.
    Another commenter stated that the open-ended nature of fire control 
components makes it difficult, if not impossible, to determine what 
constitutes the frame or receiver. The commenter explained that some 
magazine catches could be a frame or receiver because those components 
are visible from the exterior of a completed firearm and provide a 
structure to hold or integrate a component necessary for the firearm to 
initiate or continue the firing sequence (e.g., a magazine for use in a 
semiautomatic pistol equipped with a magazine disconnect). The 
commenters stated that ATF's illustrations purport to indicate that 
only one part is the frame or receiver when in fact the depictions show 
firearms with more than one component that meet the definition using 
only the listed fire control components. For example, the commenters 
stated: ``The hinged revolver example indicates that the `frame' is the 
rear half of the firearm, even though the front half of the firearm 
obviously provides a `housing or structure' to `hold or integrate' the 
cylinder when the firearm is assembled.'' Commenters also pointed out 
that ATF did not explain what it means by ``other reliable evidence'' 
where it stated that: ``Any such part identified with a serial number 
shall be presumed, absent an official determination by the Director or 
other reliable evidence to the contrary, to be a frame or receiver.'' 
Given that firearms classifications are not released to the public, the 
commenters questioned how anyone is to know whether a given firearm has 
or has not received an official determination.
Department Response
    The Department believes that the grandfather provision in the 
proposed rule would have eliminated most of the concerns raised by 
commenters concerning the proposed definition of ``frame or receiver'' 
and agrees that it relied heavily on ATF classifications of specific 
components as a ``frame or receiver.'' Nonetheless, as stated 
previously, the Department agrees with commenters that the definition 
of ``firearm'' in 18 U.S.C. 921(a)(3)(B) is best read to mean a single 
part of a weapon or device as being ``the'' frame

[[Page 24693]]

or receiver. Accordingly, the final rule adopts certain subsets of the 
proposed definition firearm ``frame or receiver'' while providing new 
distinct definitions for ``frame'' and ``receiver.'' Whereas the 
proposed rule would have considered any housing or structure for any 
fire control component a frame or receiver, the final rule focuses 
these definitions by describing a specific housing or structure for one 
specific type of fire control component. This will help licensees and 
the public determine on their own which portion of a firearm is the 
``frame or receiver'' without an ATF classification.
    In the final rule, the Department has established new definitions 
for the term ``frame'' to apply to handguns; ``receiver'' to apply to 
rifles, shotguns, and projectile weapons other than handguns; and 
``frame'' or ``receiver'' to apply to firearm mufflers and silencers. 
More specifically, with respect to handguns, the Department is adopting 
in this final rule a definition of ``frame'' that incorporates language 
similar to that proposed by commenter Sig Sauer, Inc., described below. 
The term ``frame'' will be defined as: ``the part of a handgun, or 
variants thereof, that provides housing or a structure for the primary 
energized component designed to hold back the hammer, striker, bolt, or 
similar component prior to initiation of the firing sequence (i.e., 
sear or equivalent), even if pins or other attachments are required to 
connect such component to the housing or structure.'' This definition 
is consistent with the common understanding of the term ``frame'' as 
the ``basic unit of a handgun'' that holds the ``operating parts'' of 
the weapon.\116\ These operating parts necessarily include the sear or 
equivalent component that is energized prior to initiation of the 
firing sequence.
---------------------------------------------------------------------------

    \116\ See footnote 7, supra.
---------------------------------------------------------------------------

    However, the Department does not adopt the same definition with 
respect to rifles, shotguns, and projectile weapons other than handguns 
which are commonly understood to incorporate a ``receiver.'' This term 
is generally understood to be the part ``in which the action of a 
firearm is fitted and to which the breech end of the barrel is 
attached.'' \117\ Because the ``action'' of a firearm is commonly 
understood to mean ``the physical mechanism that manipulates cartridges 
and/or seals the breech,'' \118\ the term ``receiver'' is defined in 
the final rule as: ``the part of a rifle, shotgun, or projectile weapon 
other than a handgun, or variants thereof, that provides housing or a 
structure for the primary component designed to block or seal the 
breech prior to initiation of the firing sequence (i.e., bolt, 
breechblock, or equivalent), even if pins or other attachments are 
required to connect such component to the housing or structure.''
---------------------------------------------------------------------------

    \117\ Id.
    \118\ Prasanta Kumar Das, Lalit Pratim Das, & Dev Pratim Das, 
Science and Engineering of Small Arms, Ch. 5.4 (2022).
---------------------------------------------------------------------------

    For purposes of these definitions, the terms ``variant'' and 
``variants thereof'' are defined as: ``a weapon utilizing a similar 
frame or receiver design irrespective of new or different model 
designations or configurations, characteristics, features, components, 
accessories, or attachments. For example, an AK-type firearm with a 
short stock and a pistol grip is a pistol variant of an AK-type rifle, 
an AR-type firearm with a short stock and a pistol grip is a pistol 
variant of an AR-type rifle, and a revolving cylinder shotgun is a 
shotgun variant of a revolver.'' The definition of frame or receiver 
with respect to a firearm muffler or silencer is described in Section 
IV.B.3.e of this preamble. The final rule does not adopt the proposed 
supplement entitled ``Split or Modular Frame or Receiver.''
    Additionally, in response to comments, the Department has added a 
new ``grandfather'' supplement expressly defining the term ``frame or 
receiver'' to include prior ATF classifications of a specific component 
as the frame or receiver, and clarified how multi-piece frames or 
receivers with modular subparts are defined and must be marked. These 
amendments should greatly diminish commenters' concerns regarding any 
lack of specificity or confusion regarding the particular models listed 
in the proposed definitions. The final rule includes a wide variety of 
examples and pictures to illustrate the frame or receiver of popular 
models and variants thereof, as well as examples of particular models 
previously classified by ATF that are grandfathered, such as the lower 
receiver of AR-15 variant firearms which houses the trigger mechanism 
and hammer, rather than the breech blocking or sealing component (i.e., 
the bolt).
d. Alternative Definitions of ``Frame or Receiver''
Comments Received
    Commenters opposed to the proposed rule have either urged ATF to 
withdraw the rulemaking or come up with a more concise, less complex 
definition. While some commenters agreed that ATF's current definition 
of ``frame or receiver'' is outdated, ``antiquated,'' or ``confusing,'' 
several commenters from the industry said a new definition should be 
tailored to focus on new designs and should be done with meaningful 
input from stakeholders.
    A few commenters stated that there were numerous other ways for ATF 
to amend its definition to adapt to technological advances while also 
being consistent with the wider public's longstanding interpretation of 
the term to mean a single component of a given firearm. Commenter Sig 
Sauer, Inc., for example, suggested the following possible alternative 
definitions: (1) ``Firearm frame or receiver'' means ``the component of 
the firearm which provides a housing for the component responsible for 
constraining the energized component of the firearm (i.e., the sear or 
equivalent thereof)''; (2) ``Firearm frame or receiver'' means ``the 
component of the firearm which provides a housing for the component 
which the operator interacts with to initiate the firing sequence of 
the firearm (i.e., the triggering mechanism, or the equivalent 
thereof)''; or (3) ``Firearm frame or receiver'' means ``the component 
of the firearm which incorporates or provides a housing for the 
component which interacts with the barrel to form the chamber of the 
firearm.''
    One commenter stated that ATF's goal to update the definition of 
``frame or receiver'' to accommodate split-framed firearms would be met 
simply by re-writing the existing definition to read: ``the part of a 
firearm that provides housing for the hammer, bolt or breechblock, 
firing mechanism, or at its forward portion receives the barrel.'' 
Another commenter similarly suggested that ATF use ``or'' rather than 
``and'' as the conjoiner in the current definition of ``firearm frame 
or receiver,'' such that the list of the components housed by the frame 
or receiver would read ``the hammer, bolt or breechblock, or firing 
mechanism.'' Another commenter suggested that ATF adopt the definition 
of ``receiver'' that is in the Sporting Arms and Ammunition 
Manufacturers' Institute's (``SAAMI's'') Glossary of Industry Terms 
available on that organization's website.\119\ Another commenter 
suggested a point system that would assign points (e.g., the ``fire 
control group'' would be three points, the hammer would be one point, 
and

[[Page 24694]]

the striker would be one point). Under this suggestion, the external 
part that has the most points would be the frame or receiver.
---------------------------------------------------------------------------

    \119\ SAAMI defines the term ``receiver'' as ``[t]he basic unit 
of a firearm which houses the firing and breech mechanism and to 
which the barrel and stock are assembled. In revolvers, pistols, and 
break-open guns, it is called the Frame.'' See SAAMI, Glossary of 
Industry Terms, available at https://saami.org/saami-glossary/?letter=R (last visited Mar. 25, 2022).
---------------------------------------------------------------------------

    While some commenters suggested ATF should just accept the 
manufacturer-designated component identified as ``firearm'' for each 
model, another commenter, SAAMI, suggested that, with respect to the 
AR-15 Colt Sporter, ATF could simply amend the existing regulation to 
specify that the lower receiver is the ``frame or receiver'' of that 
firearm. Another commenter suggested that frame or receiver should be 
defined as: ``that portion of the weapon, that holds the fire control 
group, consisting of any of the following, trigger, sear, safety and 
hammer if the weapon is hammer fired.'' According to the commenter, 
this would consistently mean the lower receiver and encompass all 
weapons, i.e., the lower on an AR-15, the lower on a Glock, the lower 
on a break open shotgun (not including barrel), the lower on a 
revolver, and the lower on a semiautomatic pistol would be the 
``firearm'' regardless of the striker fire or hammer fire (because it 
holds the trigger or sear). This, according to the commenter, would 
also encompass the side plate on certain machineguns.
    To address the cases in which ATF has not prevailed in litigation, 
one commenter suggested a more specific fix that would define frame or 
receiver as the ``mounting point, housing structure, or the significant 
part thereof for a firearm's barrel, barrels or barrel assembly since 
all guns have at least one barrel.'' Or, to address that striker-fired 
mechanisms are not fully captured under the current law, commenters 
said the definition could be easily amended to ``that part of a firearm 
which provides housing for the hammer or striker, bolt or breechblock, 
and firing mechanism, and which is usually threaded at its forward 
portion to receive the barrel.''
Department Response
    The Department agrees with commenters who stated that ATF's current 
definition of ``frame or receiver'' is outdated and confusing, and that 
the proposed definition should be simplified. For this reason, ATF is 
providing a new regulatory definition of ``frame or receiver'' to 
encompass existing and new firearm designs. The GCA and NFA do not 
define the term ``frame or receiver,'' so only the regulatory 
definitions of that term in 27 CFR parts 478 and 479 are being 
redefined. For the reasons previously discussed, the Department agrees 
that a more concise, less complex definition that focuses on a single 
part of each weapon is preferable, and will adopt a definition of 
``frame'' with respect to handguns and ``receiver'' with respect to 
rifles, shotguns, and projectiles weapons other than handguns.
    The Department disagrees with commenters who suggested amending the 
current definitions of ``frame or receiver'' by replacing ``and'' with 
``or'' as the conjoiner with respect to the listed components of the 
current definition. Under this alternative, any part of a firearm that 
houses either the hammer, or a bolt or breechblock, or a firing 
mechanism, or that receives the barrels would be considered frames or 
receivers. Thus, under this alternative, there could exist even more 
firearm parts that would constitute a ``frame or receiver'' than 
identified by the proposed rule. This alternative also does not 
identify a single ``receiver'' in numerous split receiver firearms. In 
an AR-15-type rifle, for example, the hammer, firing mechanism, and 
forward portion that receives the barrel are all in the lower receiver, 
but the bolt or breechblock is in the upper receiver. The same problem 
exists when applying SAAMI's definition from its Glossary of Industry 
Terms because the firing and breech mechanisms are not in the same 
``receiver.'' While the lower receiver houses the firing mechanism and 
is attached to the stock, the upper receiver houses the breechblock and 
is attached to the barrel. Therefore, under SAAMI's published 
definition, in an AR-15-type firearm, for example, there would still be 
more than one part that would be defined as a ``frame or receiver'' on 
this weapon as well as on numerous split or modular models of firearms 
in common use today. This alternative definition also does not explain 
how it would apply to firearms that do not have a hammer, but are fired 
using a striker, which may be located in different housings depending 
on the type of firearm.
    The Department also disagrees with the point system recommended by 
one commenter because it does not explain how the point values were 
reached, and why fire control components in other portions of the 
assembled weapon were not assigned any points. It would not address 
firearms that do not house all ``fire control group'' components within 
a single housing, or which have a remote trigger outside the weapon. In 
sum, this alternative would fall short of addressing all technologies 
or designs of firearms that are currently available, or may become 
available in the future. It also does not address potential changes in 
firearms terminology.
    The Department agrees with SAAMI on expressing in the final rule 
that the lower receiver of the AR-15 Colt Sporter (and variants 
thereof) is the ``receiver'' of that weapon. The final rule also 
includes a diagram of the AR-15 receiver. The Department will also 
grandfather all prior ATF classifications specifying which single 
component of a weapon is its frame or receiver. However, the Department 
will not grandfather ATF determinations that a partially complete, 
disassembled, or nonfunctional frame or receiver, including a parts 
kit, was not, or did not include, a firearm ``frame or receiver'' as 
defined prior to this rule, including those where ATF determined that 
the item or kit had not yet reached a stage of manufacture to be one. 
In any event, simply specifying that the lower receiver of the AR-15 
Colt Sporter is a ``receiver'' does not solve the problem of defining 
the term ``frame or receiver'' with respect to all of the firearms with 
a split or multi-piece frame or receiver, or those that are striker 
fired. The problem remains that a court could decide that the current 
definition of ``frame or receiver'' does not apply to those firearms. 
Thus, the existing definition is not adequate with respect to the vast 
majority of firearms currently in the United States.
    The Department declines to accept the proposed alternative 
definition saying that a ``frame or receiver'' is the portion of a 
weapon ``that holds the fire control group, consisting of any of the 
following, trigger, sear, safety and hammer, if the weapon is hammer 
fired.'' First, some firearms may be initiated manually by hand or 
``slam fired'' without a part that actually holds a trigger, sear, 
safety, and hammer, and all complete, assembled weapons must have a 
frame or receiver. Second, not all of these fire control components may 
be in the same portion of the weapon, and some fire control groups, or 
portions thereof, may be found outside the frame or receiver, or 
triggered remotely. Nonetheless, the final rule accepts this 
alternative insofar as the ``frame'' of a handgun will be defined as 
the part that provides housing for the primary energized component 
designed to hold back the hammer or striker, which is generally the 
``sear.''
    The Department also declines to accept the proposed alternative 
definition saying that the frame or receiver is the ``mounting point, 
housing structure, or the significant part thereof for a firearm's 
barrel, barrels or barrel assembly since all guns have at least one 
barrel.'' This suggested definition would be inconsistent with what ATF 
and the firearms industry have understood to be the frame or receiver 
of numerous semiautomatic handguns, such as Glock

[[Page 24695]]

and Sig Sauer pistols and variants thereof, which is the lower portion 
of the weapon housing the sear, trigger mechanism, and other fire 
control parts. In such handguns, the barrel is housed in the upper 
slide. This suggested definition would, therefore, create confusion for 
many firearm manufacturers.
    The new definitions in this rule are intended to describe the 
specific part of weapons that has traditionally been considered the 
frame or receiver for almost all firearms, but are general enough to 
accommodate future designs and changes in parts terminology. The few 
exceptions, such as the AR-15 rifle and Ruger Mark IV pistol, are 
grandfathered into the new definitions of those terms and may continue 
to be marked in the same manner as they have been prior to the 
effective date of this rule.
    The Department acknowledges comments that stated that the current 
definition does not include a housing for ``striker'' fired weapons. 
The new definitions, which focus on the housing or structure for a 
single fire control component (i.e., sear or equivalent for handguns, 
and bolt, breechblock, or equivalent for all other projectile weapons), 
are broad enough to cover both striker and hammer-fired weapons.
e. Definition of ``Firearm Muffler or Silencer Frame or Receiver''
Comments Received
    Some commenters opposed the proposed definition of ``complete 
muffler or silencer device,'' stating that the new definition would 
subject persons who possess a complete but disassembled silencer to the 
civil and criminal penalties associated with possession of a complete 
silencer. They also objected to frames or receivers of silencer 
devices, which may not be in an operational state, becoming subject to 
the new ``readily'' factors test used to establish the scope of weapon 
parts kits and firearm frame or receiver regulation. One manufacturer 
also pointed out that the definition of complete silencer device does 
not appear to include a silencer that uses a firearm-mounted flash-
hider or other attachment devices for use if the mounting device is not 
included with or attached to the silencer.
    Separately, while some commenters noted that the proposed 
definition of ``firearm muffler or silencer frame or receiver'' is an 
improvement on current law, there remains confusion regarding whether 
ATF intends for only a singular part to be the frame or receiver for 
firearm silencers. They stated that ATF should clarify in the final 
rule that firearm silencers only need to be marked on a single piece 
that is the frame or receiver. Another manufacturer raised a similar 
concern that under the proposed definition, a non-welded suppressor's 
end cap appears to be a frame or receiver requiring serialization. The 
manufacturer gave an example of Ruger Silent-SR and Silent SR ISB 
silencers that use a traditional baffle stack of non-welded individual 
baffles housed in a serialized tube. When installed, the end cap 
secures the baffles in place within the tube. The end cap, in this 
instance, seems to be a frame or receiver because it ``provides housing 
or a structure . . . designed to hold or integrate one or more 
essential internal components of the device.'' They stated that this 
conclusion, if accurate, would mean that a majority of suppressors 
utilizing a non-welded design have more than one frame or receiver, 
contrary to ATF's position.
    The same manufacturer also raised concerns about ATF's attempt to 
memorialize the longstanding policy regarding silencer parts 
transferred between qualified individuals. The proposed rule allowed 
such transfers on the condition that ``upon receipt, [the parts are] 
actively used to manufacture a complete muffler or silencer device.'' 
The manufacturer argued that this section does not seem to allow a 
qualified manufacturer to send unmarked suppressor components to 
another qualified manufacturer for further manufacturing activities 
(e.g., machining, coating, etc.) if the parts are not going to be 
assembled into a complete muffler or silencer device by the 
subcontractor manufacturer. Because ``actively'' is not defined, the 
commenting manufacturer stated it was unclear if it could transfer a 
large quantity of suppressor parts to a subcontractor to be consumed as 
needed by the manufacturer to make complete suppressors over an 
extended period.
Department Response
    As stated previously, the Department agrees with commenters that 
the term ``frame or receiver'' is best read to mean a singular frame or 
receiver that must be identified with a single unique serial number. 
This would include the frame or receiver of a complete firearm muffler 
or silencer device. The Department also agrees with the comment that an 
end cap of an outer tube or modular piece could have been considered a 
structural component within the meaning of a frame or receiver as 
proposed. End caps are often damaged or destroyed upon expulsion of 
projectiles, leaving the muffler or silencer without any traceable 
markings of identification. For this reason, the Department is amending 
the definition of those terms in the final rule as follows: ``in the 
case of a firearm muffler or firearm silencer, the part of the firearm, 
such as an outer tube or modular piece, that provides housing or a 
structure for the primary internal component designed to reduce the 
sound of a projectile (i.e., baffles, baffling material, expansion 
chamber, or equivalent). In the case of a modular firearm muffler or 
firearm silencer device with more than one such part, the terms shall 
mean the principal housing attached to the weapon that expels a 
projectile, even if an adapter or other attachments are required to 
connect the part to the weapon. The terms shall not include a removable 
end cap of an outer tube or modular piece.''
    The Department also agrees with the commenter who stated that the 
proposed provision concerning transfers of firearm mufflers or 
silencers between qualified licensees could be read to exclude further 
manufacturing activities, such as further machining or applying 
protective coatings. For this reason, the Department has removed the 
term ``actively,'' and, instead, explained that mufflers or silencers 
must be marked by close of the next business day after the entire 
manufacturing process has been completed. The Department has also made 
minor amendments to the marking allowances to make clear that mufflers 
or silencers may be transferred between qualified manufacturers for 
further manufacture (i.e., machining, coating, etc.) without 
immediately identifying and registering them. Once the new device with 
such part is completed, the manufacturer of the device must identify 
and register it in the manner and within the period specified in this 
part for a complete muffler or silencer device.
f. Definition of ``Split or Modular Frame or Receiver''
Comments Received
    With respect to ATF classifying the frame or receiver of a split or 
modular frame or receiver, numerous commenters objected to the 
definition not only on the grounds that it was too broad and confusing, 
but that to obtain certainty, it was largely dependent on ATF making 
classifications. They critiqued this process as lacking transparency, 
objectivity, and efficiency, as well as placing too much power in the 
hands of ATF. Numerous commenters said they introduce new models 
multiple times per year, and assuming a new determination is needed for 
each new model or

[[Page 24696]]

configuration, they have serious concerns that classification process 
would bury them in red tape. They stated the lead time, which is 
currently 6-12 months or more, would be much longer if hundreds of 
manufacturers were submitting to determine which component qualifies as 
the receiver, and this would be costly and disruptive to their 
companies. Due to the current delays in obtaining classifications, one 
commenter suggested the proposal could discourage classification 
requests rather than encourage them.
    Several industry members stated that the firearm specific 
definitions under ``split or modular frame or receiver'' are confusing. 
It is not clear if the definitions apply only to firearms produced by 
those manufacturers listed or if it applies to all firearms that follow 
the same basic design. The confusion, they stated, is evident in the 
first of these definitions for ``Colt 1911-type, Beretta/Browning/FN 
Herstal/Heckler & Koch/Ruger/Sig Sauer/Smith & Wesson/Taurus hammer 
fired semiautomatic pistols.'' They questioned if the definition 
applies only to hammer-fired semiautomatic pistols manufactured by 
these discrete manufacturers or applies to all firearms that integrate 
an operating system that matches ATF's provided definition for these 
firearms. Similarly, they stated ATF's use of ``-type'' was unclear and 
asked, for instance, if ``Sig Sauer P320-type semiautomatic pistols'' 
is meant to include only P320s or exact replicas thereof, or if it is 
meant to convey a broader meaning of any firearm that has the same 
basic design, even if it uses different materials or has different 
gross dimensions (such as the Sig P365).
    Additionally, commenters stated the nonexclusive lists used in 
definitions for frame or receiver indicated that there are other 
firearms designs and configurations not listed that fall into the 
category of ``-type'' but that are unknown to the public. Commenters 
also questioned what ATF meant by ``comparable'' when the NPRM 
explained that split or modular firearm designs that are not comparable 
to an existing classification would not be grandfathered in under the 
rule, thus making it possible that more than one part of the firearm 
would be the ``frame or receiver'' under the proposed definition.
    Numerous commenters noted that several models of firearms were 
missing from the list of examples under the supplemental definition of 
frame or receiver entitled ``split or modular frame or receiver'' and 
that without clearer, more articulate lists, it appears that several 
models would be subject to more marking requirements. One commenter, an 
FFL/SOT, expressed that the examples provided in the definitions do not 
include the most widespread and popular 22LR pistols such as the Ruger 
Mark I/II/III/IV, Browning Buckmark, S&W Model 41, and similar designs. 
They stated that millions of these have been sold over the past 70 
years with the serialized firearm component varying between models from 
the assembly containing the barrel to the assembly containing the 
trigger mechanism. Without addressing these models, the comment said it 
is not clear where serialization should occur.
    Similarly, another commenter provided examples of three models--the 
512 Remington ``Sportmaster'' .22 rimfire bolt action tubular repeater, 
the 9422 Winchester .22 rimfire lever action repeater, and the 1911 and 
1911A series Colt--and listed several parts of each firearm that the 
commenter believes would be subject to the marking requirements under 
the proposed definition. The FN PS90 firearm was another model raised 
as to which a commenter did not understand how the new definition would 
apply. The commenter stated that the upper of the FN PS90 is the 
serialized component and that the stock assembly (made entirely out of 
plastic) is a stock. Under the NPRM's definition, the commenter stated 
that the stock would need to be serialized because it is made of two 
externally visible parts bolted together. Therefore, the commenter 
questioned whether each half of the stock would require its own serial 
number or if the parts would need to have injection molding done by a 
Type 07 licensee. Another commenter opined that the example for AK-type 
firearms is not consistent with many existing AK-type firearms already 
lawfully possessed. The commenter stated that while many of these 
firearms are marked on the identified ``single receiver,'' many of 
these types of firearms have been imported with the serial number only 
marked on the front trunnion. Thus, the commenter asked that this 
example be re-evaluated since it is unlikely ATF is intending to 
identify an unmarked part of thousands of firearms. Other commenters 
similarly said that ATF made an error when it listed the frame or 
receiver for a Beretta AR-70 type as the lower receiver because under 
existing precedent, the upper receiver of the AR-70 has been treated as 
the frame or receiver.
    Finding the nonexclusive lists of frame or receiver examples to be 
inadequate and likely to lead to confusion or resulting in thousands of 
unnamed firearm types that will, by default, have multiple frames or 
receivers, other commenters said ATF should make all known or existing 
classifications public or listed in the final rule. It is, they argued, 
the only way to ensure fairness.
Department Response
    The Department agrees with numerous commenters that the supplement 
to the definition entitled ``split or modular frame or receiver'' would 
have been difficult for persons to apply under the proposed definition 
of ``frame or receiver'' that meant a housing for any fire control 
component. Additionally, the Department acknowledges commenters' 
concerns that many models of firearms were not included, and that the 
proposed definition could lead persons to submit new classification 
requests rather than relying on the definition to identify the frame or 
receiver.
    The Department, in response to these comments, is finalizing a 
definition of ``frame or receiver'' in a new Sec.  478.12 that 
incorporates limited subsets of the proposed definition while providing 
distinct definitions for ``frame'' and ``receiver.'' The new 
definitions under ``frame or receiver'' focus on only one housing or 
structural component for a given type of weapon. Because the final rule 
focuses on a single component based on the recommendations of 
commenters, there is no longer a need for the supplement entitled 
``split or modular frame or receiver,'' and it is not adopted in the 
final rule. The Department also acknowledges that the lower portion of 
the AR-70 was mistakenly identified as the receiver of that firearm in 
the NPRM. Under the final rule, the upper portion of the AR-70 remains 
the receiver of that firearm as described by the new definition of 
``receiver.''
    Furthermore, to ensure that industry members and others can rely on 
ATF's prior classifications, most prior ATF classifications, and 
variants thereof, have been grandfathered into the new definition of 
``frame or receiver'' along with examples and diagrams of some of those 
weapons, such as the AR-15 rifle and Ruger Mark IV pistol. The only 
exceptions are classifications of partially complete, disassembled, or 
nonfunctional frames or receivers that ATF had determined did not fall 
within the definition of firearm ``frame or receiver'' prior to this 
rule. Any such classifications, including parts kits, would need to be 
resubmitted for evaluation. If persons remain unclear which specific 
portion of a weapon or device falls within the definitions of ``frame'' 
or ``receiver,'' then they may

[[Page 24697]]

voluntarily submit a request to ATF as provided in this rule.
g. Alternative for Defense Industry Under ``Split or Modular Frame or 
Receiver''
Comments Received
    Another commenter who represents members of the defense 
manufacturing industry suggested including as an example (``box-type'') 
of a split frame or receiver for which a single part had been 
previously classified by the Director ``externally powered weapons.'' 
The commenter explained as follows: Some externally powered designs 
include a part called the ``front housing'' that directly attaches to 
the existing frame or receiver and houses the breech. The front housing 
positions the breech to align with the bolt, which in turn, allows the 
bolt assembly to properly lock and drop the firing pin when the barrel 
is installed. Under the proposed definition, the commenter observed, it 
appears that this ``front housing'' could include this and other parts 
of the weapon not previously understood to be the frame or receiver, in 
addition to the existing ``bathtub'' or box-type receiver. As an 
alternative, the commenter suggested adding language that would exempt 
``externally powered weapons'' that require ``a separate electronic gun 
control unit to fire, and which [are] used solely in a government 
military platform, simulation, or training exercise, and where the 
weapon's design does not have a civilian surrogate,'' from either the 
definition of ``partially complete'' frames or receivers or 
``readily.''
    As a completely different alternative, the same commenter requested 
that ATF include a simple annual notification procedure where qualified 
defense importer and manufacturer licensees could prove that they meet 
``opt out'' requirements of the proposed rule and proceed with their 
processes under the existing regulatory requirements. The commenter 
suggested an ``opt out'' provision because the increased compliance 
obligations of the proposed rule would further complicate an already 
challenging workflow and impede contractual deadlines the commenter's 
clients have with the U.S. Government.
Department Response
    The Department declines to adopt the commenter's suggestion to add 
ATF's classification of ``externally powered weapons.'' As described 
above, the final rule grandfathers most prior ATF classifications and 
variants thereof, including ``box-type'' or externally powered weapons, 
into the new definition of ``frame or receiver'' along with examples 
and a diagram of those weapons. The Department also declines to adopt 
the suggestion allowing qualified defense importer and manufacturer 
licensees to opt out from the proposed rule and proceed with their 
processes under the existing regulatory requirements. The GCA, 18 
U.S.C. 925(a), does not exempt the manufacture of firearms for the 
government from the licensing, marking, and other requirements imposed 
on manufacturers. It only exempts the transportation, shipment, 
receipt, possession, or importation of firearms sold or shipped to, or 
issued for the use of, the government. Otherwise, unmarked, untraceable 
firearms manufactured for the government could be lost or stolen 
without any ability to trace them if later involved in crime.
h. Definition of ``Partially Complete, Disassembled, or Inoperable 
Frame or Receiver''
Comments Received
    Commenters opposed to inclusion of partially complete frames or 
receivers in the proposed definition of frame or receiver stated that 
the proposed rule would be difficult, if not impossible, to enforce. 
They opined that there is no purpose in trying to ``ban 80%'' receivers 
or regulate partially complete receivers because the rule is easily 
undercut by 3D-printing technology and the availability of online 
tutorials, which will only become more available and affordable for the 
public over time. One commenter, for example, stated that, even if all 
unfinished, or ``80%,'' receivers were taken away, firearms could still 
be made through other means, citing the FGC9 as an example. Because the 
commenter believes that technology undercuts the rule, the commenter 
argued that the new definitions and marking requirements serve no 
purpose and should not be adopted.
    Commenters also had several questions about the terms used in the 
definition of partially complete frame or receiver such as what it 
means for an item to cross the critical line to where it ``reach[es] a 
stage of manufacture where it is clearly identifiable as an unfinished 
component part of a weapon.'' Other commenters asserted that the 
definition lacks objectivity and there are no objective metrics to 
guide the factors that are listed. With the proposed changes, the 
commenters questioned the meaning of ``functional state.'' Similarly, 
although ATF stated in the preamble that unformed blocks of metal or 
articles in a primordial state ``without more'' would not be considered 
a partially complete frame or receiver, commenters stated that it is 
still unclear when these items fall under the definition where, for 
example, there were instruction booklets, metal working tools, or 
tutorial videos, because the definition hinges on what ``without more'' 
means, which ATF did not explain.
    Manufacturers also raised concerns because they purchase partially 
machined raw materials or receiver shells without drilled fire control 
holes from domestic and foreign sources that are not current licensees. 
The manufacturers were concerned that the proposed rule would 
subsequently require their suppliers to obtain an FFL license, apply 
the markings, and keep A&D records, which would be very costly and 
disruptive. Another commenter suggested that ``critical stage of 
manufacture'' should be amended to say: ``when the article becomes 
sufficiently complete to function as a frame or receiver.''
Department Response
    The Department disagrees with commenters who stated that inclusion 
of partially complete frames or receivers in the proposed definition of 
frame or receiver would be difficult, if not impossible, to enforce. 
The proposed and final rule both make clear that a partially complete 
frame or receiver must have reached a stage of manufacture where it is 
clearly identifiable as a component part of weapon to be classified as 
a potential frame or receiver. Such articles have been regulated for 
importation and exportation since at least 1939.\120\ With regard to 
3D-printed PMFs, this rule explains that, as technology progresses, 
PMFs are likely to make their way to the licensed community because 
firearms licensees are likely to market them for sale, accept them into 
pawn, or repair them through gunsmithing services. Additionally, the 
GCA requires out-of-State firearm transfers to go through licensees, 
and some States require firearm sales or transfers to be conducted 
through licensees.\121\
---------------------------------------------------------------------------

    \120\ See footnote 78, supra.
    \121\ See 18 U.S.C. 922(a)(5); Cal. Penal Code 27545; Colo. Rev. 
Stat. 18-12-112(2)(a); Conn. Gen. Stat. 29-36l(f), 29-37a(e)(2); 
D.C. Code Ann. 7-2505.02(a); Del. Code. tit. 11 1448B(a); 430 ILCS 
65/3(a-10); Md. Code, Public Safety 5-204.1(c)(1); Nev. Rev. Stat. 
202.2547(1); N.J. Stat. Ann. 2C:58-3(b)(2); N.M.S.A. 30-7-7.1(A)(2); 
N.Y. Gen. Bus. Law 898(2); Or. Rev. Stat. 166.435(2); 18 Pa. C.S.A. 
6111(c); Vt. Stat. Ann. tit. 13, 4019(b)(1); Va. Code An. 18.2-
308.2:5(A); Rev. Code Wash. 9.41.113(3).
---------------------------------------------------------------------------

    However, the Department agrees with commenters that the supplement 
to the

[[Page 24698]]

proposed definition of ``frame or receiver'' entitled ``partially 
complete, disassembled, or inoperable frame or receiver'' should be 
revised to provide more guidance on the application of the definition. 
In the final rule, the Department has: (1) Removed the definition of 
``partially complete'' as it modified the term ``frame or receiver'' 
and, instead, has expressly excluded from the definition of ``frame or 
receiver'' forgings, castings, printings, extrusions, unmachined 
bodies, or similar articles that have not yet reached a stage of 
manufacture (e.g., unformed blocks of metal, liquid polymers, or other 
raw materials) where they are clearly identifiable as an unfinished 
component part of a weapon; (2) made related clarifying amendments, 
such as changing the term ``inoperable'' to the more accurate term 
``nonfunctional,'' \122\ and expressly stating that the section 
includes frame or receiver parts kits that are designed to be--or may 
readily be--completed, assembled, restored, or otherwise converted to a 
functional state; (3) explained the meaning of the term ``functional 
state'' to be a frame or receiver that houses or provides a structure 
for the primary energized component of a handgun, breech blocking or 
sealing component of a projectile weapon other than a handgun, or 
internal sound reduction component of a firearm muffler or firearm 
silencer, as the case may be; and (4) included detailed examples of 
what would and would not be considered a ``frame or receiver'' that may 
readily be completed, assembled, restored, or otherwise ``converted'' 
to a functional state. Thus, as the proposed rule explained, articles 
that are not clearly identifiable as component parts of a weapon cannot 
be considered frames or receivers. See 86 FR at 27729. And even 
articles that are clearly identifiable as a partially complete, 
disassembled, or nonfunctional frame or receiver of a weapon are not 
frames or receivers under the new definitions unless they are designed 
to function as a frame or receiver, or may readily be completed, 
assembled, restored, or otherwise converted to do so.
---------------------------------------------------------------------------

    \122\ ``Nonfunctional'' is more accurate because, although the 
weapons in which they are incorporated are ``operated'' by a 
shooter, frames or receivers are not operated by a person. Rather, 
frames or receivers are better described as ``functional'' or 
``nonfunctional'' in that they may or may not be in a state of 
completion where they can house or hold the fire control components 
that allow the shooter to operate the weapon.
---------------------------------------------------------------------------

    The Department disagrees with the comment that the supplement 
should be amended to say that a frame or receiver means one that has 
reached a stage in manufacture ``when the article becomes sufficiently 
complete to function as a frame or receiver.'' The GCA does not explain 
when an article becomes sufficiently complete to be a frame or 
receiver. As stated previously, to determine when a frame or receiver 
is created, this rule is guided by the definition of ``firearm'' in 
section 921(a)(3)(A), the definition of ``machinegun'' in 26 U.S.C. 
5845(b), and relevant case law interpreting when a weapon ``may readily 
be converted to expel a projectile by the action of an explosive'' and 
``can readily be restored to shoot.'' \123\ This rule adopts these 
statutory concepts and case law so that ATF's regulations more plainly 
indicate that a clearly identifiable component part of a weapon becomes 
a frame or receiver when it may readily be completed, assembled, 
restored, or otherwise ``converted'' to function as a frame or 
receiver, i.e., to house or provide a structure for the primary 
energized component of a handgun, breech blocking or sealing component 
of a projectile weapon other than a handgun, or internal sound 
reduction component of a firearm muffler or firearm silencer, as the 
case may be.
---------------------------------------------------------------------------

    \123\ See footnotes 43 and 44, supra.
---------------------------------------------------------------------------

i. Definition of ``Destroyed Frame or Receiver''
Comments Received
    A few commenters opined on the proposed definition of ``destroyed 
frame or receiver,'' which would not be considered a frame or receiver 
under the definition. Some stated that the definition for ``destroyed 
frame or receiver'' contradicts the definition for ``partially 
complete, disassembled, or inoperable frame or receiver'' because, 
according to the commenters, they are both in the same state as not 
being operable to create a working firearm and therefore ATF cannot 
regulate them as frames or receivers while also excluding them from the 
definition. Another commenter disagreed with ATF's requirement that a 
cutting torch needs to be used to sever at least three critical areas 
of the frame or receiver to be an acceptable method of destruction. The 
commenter stated that, for polymer frames or receivers, simply cutting 
the frame or receiver in three critical areas should be enough because 
it could never be repaired by a reverse process and that a cutting 
torch is unnecessary to permanently destroy polymer frames.
Department Response
    The Department disagrees that the definitional supplement 
concerning destroyed frames or receivers contradicts the supplement 
entitled ``partially complete, disassembled, or inoperable'' (now 
``nonfunctional'') ``frame or receiver.'' Under that supplement, a 
partially complete, disassembled, or nonfunctional frame or receiver is 
considered a ``frame or receiver'' if it is designed to, or may readily 
be converted to, expel a projectile by the action of an explosive. That 
supplement does not address destruction, which is addressed in the 
supplement entitled ``destroyed frame or receiver.'' A destroyed frame 
or receiver is one that has been permanently altered such that it may 
not readily be completed, assembled, restored, or otherwise converted 
to function as a frame or receiver. That supplement further explains 
how destruction may be accomplished--completely melting, crushing, or 
shredding the frame or receiver, or other method approved by the 
Director. The torch cut method in the proposed rule was cited only as 
one acceptable method, but it is not the only method.\124\ To avoid 
confusion on this issue, the final rule replaces the stated methods 
with ``or other method approved by the Director.''
---------------------------------------------------------------------------

    \124\ See ATF, How to Properly Destroy Firearms (Aug. 14, 2019), 
available at https://www.atf.gov/firearms/how-properly-destroy-firearms; ATF Rul. 2003-1 (destruction of Browning M1919 type 
receivers); ATF Rul. 2003-2 (FN FAL type receivers); ATF Rul. 2003-3 
(Heckler & Koch G3 type receivers); ATF Rul. 2003-4 (Sten type 
receivers).
---------------------------------------------------------------------------

j. Definition of ``Readily''
Comments Received
    Numerous commenters criticized the proposed definition of 
``readily,'' which would be relied upon to determine, in part, if a 
partially completed frame or receiver falls under the definition of 
``frame or receiver'' or if a weapon parts kit falls under the 
definition of ``firearm.'' The overwhelming concern raised was that the 
definition of ``readily'' is a nonexclusive list of numerous factors, 
none of which is controlling, and which includes subjective 
considerations that could leave it unclear to the industry and public 
when an item meets any particular definition. Commenters, for instance, 
explained that parts could be a firearm if an expert using specialized 
tools assembled it in ten minutes if ATF were to focus on the factors 
of time and ease; alternatively, those same parts assembled in that 
scenario might not be a firearm if ATF were to focus on the factors of 
expertise and equipment. Similarly, others argued that all the terms 
were impermissibly vague or

[[Page 24699]]

arbitrary. For example, these commenters stated that ``expertise'' is 
wholly subjective and that ATF did not identify what knowledge or 
skills are essential to making a firearm.
    One trade group stated that several major manufacturers 
communicated that as many as seven or more stages of a pistol's 
receiver construction could be called into question under the proposed 
definition because it is not clear when a frame or receiver is 
``readily completed.'' Each stage of the process, the group argued, 
could require serialization and recordkeeping. The group said that 
changing the standard of requiring serialization from only finished 
products to those that are ``readily completed'' is confusing to both 
manufacturers and their suppliers. Additionally, as mentioned above, 
manufacturers expressed concern that the products they receive from 
non-licensed third-party suppliers could fall under the definition of 
``partially complete.''
    Various commenters argued that expansive definitions of 
``readily,'' when applied to a partially complete frame or receiver, 
could result in steel or aluminum billets, castings, forgings, or even 
simple glass reinforced nylon raw materials being considered firearms. 
Numerous commenters focused on the factor of ``time'' under the 
proposed definition of ``readily,'' arguing that it is not an adequate 
factor, without more specificity, by which to measure if a weapon parts 
kit or partially completed frame or receiver may be readily convertible 
or assembled into a firearm. Commenters pushed back against ATF's 
reliance on some of the court cases ATF cited as support for the 
factors to define the term ``readily.'' They stated several of the 
cases are from the 1970s and discuss a wide range of what constitutes 
readily convertible, ranging from 12 minutes, to 1 hour, to an 8-hour 
working day in a ``properly equipped'' machine shop. Thus, what one 
expert may accomplish easily in 20 minutes may require hours of hard 
work for a novice. One manufacturer, Polymer80, also critiqued ATF for 
not supplying a metric for time and for stating in a footnote that 
Polymer 80 assembly could be completed in under 30 minutes, leaving the 
company to wonder if 30 minutes is the standard. One commenter 
suggested that eight hours of work would be a reasonable threshold.
    Some commenters believed that ATF's own rulings and public 
statements in cases such as California v. ATF, mentioned above, 
contradict the notion that it is easy to finish lower receivers with 
simple possession of hand tools in a way that would bring them under 
the definition of ``frame or receiver.'' Commenters argued that the 
process of converting an unfinished lower receiver into a finished 
lower receiver requires specialized equipment, precision tools, skill, 
and time. Users, according to the commenters, must purchase numerous 
parts and assemble them with care. Similarly, other commenters, under 
the assumption that an ``80% lower receiver'' would be included under 
the definition of partially complete frame or receiver, argued that 
this item ``cannot fire blank cartridges, nor can it be `readily 
converted' to do so,'' because multiple holes have to be drilled and 
complex mechanical parts need to be attached. They stated that the AR-
15 lower receiver is a ``frame or receiver'' once it becomes an 
integral component containing a fire control group and is attached via 
the takedown pins to the other components required to form a complete 
weapon in the AR-15 design pattern.
    Others pointed out technological advances, such as CNC machines, 
that can convert metal ingots into a functional firearm, thus raising 
the question of whether a CNC machine sold alongside the ingots would 
be considered a firearm. Similarly, commenters questioned whether a 3D 
printer shipped with filament and files of 3D representations of 
firearms would constitute a firearm under the readily convertible test. 
Further, according to one commenter, in a ``properly equipped'' machine 
shop today, it would not be uncommon for the shop to acquire a three-
axis CNC machine with a fourth axis trunnion for less than $10,000 
(Tormach PCNC 440 with microARC 4). Accordingly, the commenter argued 
that the existing case law upon which ATF relies does not serve to 
narrow and clarify the definition of ``readily convertible.'' 
Commenters asserted that no one can predict what ``instructions, 
guides, templates, [and] jigs'' the ATF Director will rely on in any 
given case. Commenters argued that ATF needs to remedy the definition 
with exact definitions of time, ease, expertise, equipment, 
availability, expense, and scope.
    Other commenters noted that the term ``readily'' is used throughout 
the GCA in several contexts, including interstate transportation of 
firearms (18 U.S.C. 926A) and for the importability of firearms 
generally recognized as particularly suitable or readily adaptable for 
sporting purposes (18 U.S.C. 925(d)(3)). Commenters also noted that 
there are countless other uses of the term ``readily'' throughout ATF 
regulations, such as in 27 CFR 478.92(a)(1)(i) (stating that ``[t]he 
serial number must be placed in a manner not susceptible of being 
readily obliterated''), or in 27 CFR 479.131 (requiring that certain 
records be ``readily accessible for inspection at all reasonable times 
by ATF officers''). The commenters asserted that ATF's proposed 
definition will impact all these other places where the term 
``readily'' qualifies certain provisions and that ATF's proposed 
nonexclusive list of factors would not provide clarity in those 
contexts, either.
    One commenter suggested that the term ``readily'' be removed from 
the proposed definition so it reads: ``The term `frame or receiver' 
shall include, in the case of a frame or receiver that is partially 
complete, disassembled, or inoperable, a frame or receiver that has 
reached a stage in manufacture where it is clearly identifiable by 
mechanical properties, material composition, geometry or function as an 
unfinished component part of a weapon. For purposes of this definition, 
the term `partially complete,' as it modifies `frame or receiver' means 
a forging, casting, printing, extrusion, machined body, or similar 
article.''
    Other commenters questioned whether ``solvent traps,'' which they 
asserted are legitimate devices and sometimes resemble silencers, would 
be considered readily convertible under the new regulations. Although 
some individuals file an ATF Form 1 under the NFA to make solvent traps 
silencers, the commenters stated that persons using solvent traps as 
actual solvent traps should be allowed to transfer them across State 
lines without violating the GCA or becoming subject to the NFA.
Department Response
    The Department disagrees that the term ``readily'' and the related 
nonexclusive list of factors when classifying firearms should be 
removed from the rule. As stated previously, the term ``readily'' has 
been adopted to determine when a weapon is considered a ``firearm'' 
under 18 U.S.C. 921(a)(1)(A), and also when the critical stage of 
manufacture has occurred in which an unfinished component part of a 
weapon becomes a ``frame or receiver'' under 18 U.S.C. 921(a)(3)(B). To 
explain the meaning of that term, this rule first sets forth a common 
dictionary definition of that term and then provides more clarity on 
how the term ``readily'' is used to classify firearms by listing 
relevant factors that courts have

[[Page 24700]]

adopted when making that determination.\125\
---------------------------------------------------------------------------

    \125\ See footnote 43, supra.
---------------------------------------------------------------------------

    The Department disagrees that these factors should incorporate 
minimum time limits, percentages of completion, or levels of expertise, 
or otherwise create thresholds to determine when weapon or frame or 
receiver parts are ``readily'' converted. Enumerating in this rule how 
each of the factors would apply to the manifold designs and 
configurations of firearms and aggregations of firearm parts now in 
existence, or to those that may be produced in the future, would be 
difficult, if not impossible. However, the Department agrees that more 
clarity as to how the term ``readily'' is applied would help address 
commenters' concerns. In the final rule, the Department: (1) Expressly 
excludes from the definition of ``frame or receiver'' unformed blocks 
of metal, liquid polymers, and other raw materials; (2) changes the 
term ``inoperable'' to the more accurate term ``nonfunctional''; (3) 
expressly includes frame or receiver parts kits; (4) explains the 
meaning of ``functional state''; and (5) provides detailed examples of 
when an unassembled or damaged frame or receiver, frame or receiver 
parts kit, or partially complete billet or blank, as the case may be, 
would be considered a ``frame'' or ``receiver'' because it may readily 
be completed, assembled, restored, or otherwise converted to a 
functional state. Although it would indeed be difficult, if not 
impossible, for ATF to provide examples of every possible state of 
completion or configuration of weapons or weapon parts, the proposed 
definition provides clarity on how the term ``readily'' is applied to 
the definition of ``firearm,'' and numerous courts have upheld the 
application of that term in related criminal and civil cases against 
constitutional vagueness challenges.\126\
---------------------------------------------------------------------------

    \126\ See footnote 79, supra.
---------------------------------------------------------------------------

    The Department disagrees that application of the term ``readily'' 
in this rule will require manufacturers to serialize and record frames 
or receivers in each stage of the manufacturing process. First, the 
final rule expressly excludes from the definition of ``frame or 
receiver'' forgings, castings, printings, extrusions, unmachined 
bodies, or similar articles that have not yet reached a stage of 
manufacture where they are clearly identifiable as unfinished component 
parts of a weapon, such as unformed blocks of metal, liquid polymers, 
and other raw materials. Thus, it is not until articles have been 
fashioned into unfinished frames or receivers that they are subject to 
the ``readily converted'' standard. Manufacturers and importers should 
already know that these items have been regulated as ``defense 
articles'' for purposes of importation and exportation for many 
decades.\127\ Second, as the examples in the final rule illustrate, 
only once a frame or receiver blank or billet is produced for sale or 
distribution must a determination be made whether the seller or 
distributor of the item or kit provides, or makes available to the 
purchaser or recipient of the item or kit, an associated template, jig, 
or tool that would allow the purchaser or recipient of the billet or 
blank to complete the frame or receiver fairly or reasonably 
efficiently, quickly, and easily. Companies that sell or distribute 
only unfinished frame or receiver billets or blanks, and not any 
associated jigs, templates, or similar tools to the same customer are 
not required to be licensed or to mark those articles with identifying 
information. However, companies that sell or distribute firearm parts 
kits, jigs, templates, or tools to the same customer with partially 
complete frames or receivers allowing them to be efficiently, quickly, 
and easily converted into functional weapons or functional frames or 
receivers must be licensed; must apply identifying markings to the 
partially complete frames or receivers; and must record them as 
firearms in their required records. Finally, under this rule, licensed 
manufacturers who receive non-firearm billets or blanks are not 
required to mark them until after the entire manufacturing process has 
ended for the complete weapon, or for the frame or receiver to be sold, 
shipped, or distributed separately, as the case may be--seven days in 
the case of GCA firearms and by close of the next business day in the 
case of NFA firearms.
---------------------------------------------------------------------------

    \127\ See footnote 78, supra.
---------------------------------------------------------------------------

    The Department agrees with commenters who said that the term 
``readily'' has other applications in the statute and regulations that 
have nothing to do with the enumerated factors. For this reason, the 
Department has made minor changes to this definition in the final rule 
to make clear that this term can apply to any process, action, or 
physical state, and that the listed factors relate only to firearm 
classifications, as follows: ``A term that describes a process, action, 
or physical state that is fairly or reasonably efficient, quick, and 
easy, but not necessarily the most efficient, speediest, or easiest 
process, action, or state. With respect to the classification of 
firearms under this part, factors relevant in making this determination 
include the following:''.
    With regard to certain items marketed as ``solvent traps,'' the 
definition of ``firearm silencer'' in 18 U.S.C. 921(a)(24) means ``any 
device for silencing, muffling, or diminishing the report of a portable 
firearm, including any combination of parts, designed or redesigned, 
and intended for use in assembling or fabricating a firearm silencer or 
firearm muffler, and any part intended only for use in such assembly or 
fabrication.'' A so-called ``solvent trap'' that has been indexed for 
the purpose of allowing the end user to drill a hole for the passage of 
a projectile to diminish the report of a portable firearm is intended 
only for use in fabricating a silencer. It is, by definition, a 
``firearm silencer'' without regard for the definition of the term 
``readily'' or the application of the term ``may readily be 
converted.''
k. Definition of ``Complete Weapon''
Comments Received
    Some commenters argued that ATF's definition of a ``complete 
weapon'' is illogical because it includes ``a firearm that contains all 
component parts necessary to function as designed whether or not it is 
assembled or operable.'' They objected to the inclusion of operability, 
stating that, if it is inoperable, it is not a weapon. They also 
objected to inclusion of an unassembled weapon, as they believed this 
inclusion would create tremendous enforcement uncertainty. Commenters 
asserted that law-abiding gun owners who legally own both AR rifles and 
pistols could be charged with a felony if they store their firearms 
unassembled. Other commenters stated that the definition of ``complete 
weapon'' only generates confusion because, in their view, a ``firearm'' 
would legally be a ``firearm'' whether or not it is a ``complete 
weapon'' under the NPRM.
Department Response
    For the reasons previously discussed, the Department disagrees that 
inoperable or nonfunctional firearms are not ``weapons,'' and that the 
application of the definition of ``firearm'' to unassembled weapons 
creates enforcement uncertainty.\128\ Firearms manufacturing is a 
continuum from raw material to a functional item, and the term 
``complete weapon'' is needed to explain when the frame or receiver of 
a weapon in the process of being manufactured must be identified and 
recorded as required by the regulations.

[[Page 24701]]

Specifically, under this rule, frames or receivers of non-NFA weapons 
that are in the process of being manufactured as part of complete 
weapons may be marked and recorded by a licensed manufacturer up to 
seven days after the entire manufacturing process for the complete 
weapon has ended. Complete NFA weapons, consistent with the 
recordkeeping requirement in 27 CFR 478.123(a) and Form 2 submission 
requirement in 27 CFR 479.103, must be marked by close of the next 
business day after manufacture. Such complete weapons may be sold in an 
unassembled configuration or may be inoperable due to poor workmanship 
or design. But the fact that a complete weapon is sold or distributed 
unassembled, or happens to be currently inoperable, does not remove the 
requirement for identifying markings to be placed on the frame or 
receiver.
---------------------------------------------------------------------------

    \128\ See Section IV.B.3.h, supra.
---------------------------------------------------------------------------

    The term ``complete weapon'' is also used in the rule to explain 
that frames or receivers and other parts defined as ``firearms'' that 
are not component parts of a complete weapon at the time they are sold, 
shipped, or disposed of must be marked with all required markings 
within the specified time limits from completion so they can be traced 
if lost or stolen. The term is also needed to explain what it means to 
``conspicuously'' mark firearms with serial number and other marks of 
identification. Markings must be unobstructed by other markings when 
the complete weapon is assembled.
l. Definition of ``Privately Made Firearm''
Comments Received
    One organization stated that the definition of PMF, which does not 
include firearms made prior to October 22, 1968 (unless remanufactured 
after that date), does not distinguish between a commercially made pre-
1969 firearm and those made privately. The organization stated that 
sometimes one cannot tell if a firearm has had its serial number 
defaced or removed. As a result, according to the organization, dealers 
will decline to transfer or sell a firearm with no serial number 
without regard to whether it is a PMF. Further, an individual may or 
may not know, or can be wrong or mislead a dealer about, whether a 
particular weapon is a PMF or just an old firearm. Other commenters 
objected on grounds that thousands of gun owners who bought or made 
firearms before 1969 would become criminals because there is no way to 
tell if the firearms, which do not have serial numbers, were made 
before or after 1969.
Department Response
    The Department agrees that the exclusion for pre-October 22, 1968, 
firearms from the definition of PMF does not distinguish between 
firearms that were commercially manufactured from those that were 
privately made because that definition refers to firearms produced by 
persons licensed under the GCA on or after that date. See 18 U.S.C. 
921(a)(10) (defining ``licensed manufacturer'' as a person licensed 
under the provisions of chapter 44 of title 18). To make this clear, 
the final rule adds the term ``manufactured'' to that exception. 
However, the Department disagrees that the pre-October 22, 1968, 
exclusion from the definition of PMF raises concerns because it is not 
difficult for licensees to know if a firearm, whether or not it is a 
PMF, was manufactured or made prior to October 22, 1968. First, pre-
October 22, 1968, firearms in circulation generally have some marks of 
identification. PMFs, by definition, are not marked with a serial 
number placed by a person licensed as a manufacturer under the GCA at 
the time the firearm was produced. Regulations implementing the Federal 
Firearms Act of 1938 required all firearms manufactured after July 1, 
1958, to be identified with the name of the manufacturer or importer, a 
serial number, caliber, and model. See Internal Revenue Service, 
Department of the Treasury, 23 FR 343 (Jan. 18, 1958). The only 
exception from marking the serial number and model requirements was for 
shotguns and .22 caliber rifles not subject to the NFA. Id. at 346. 
Thus, the name of the manufacturer and caliber would still be marked on 
all commercially produced weapons, even though this subset of GCA 
firearms may not display a serial number or model (though some will). 
Second, there are few firearms in circulation manufactured prior to 
1969 that were not commercially produced. As the rule explains, only in 
the past few years has technology advanced to allow individuals to 
quickly and easily make their own firearms for personal use from parts 
kits or 3D printers. Third, if a person is in doubt about whether a 
particular firearm without any markings was manufactured or made prior 
to October 22, 1968, there are many licensee and nonlicensee experts 
who can evaluate the firearm and provide an expert opinion, including 
as to whether the serial number on the firearm has been altered or 
obliterated. Additionally, persons may voluntarily seek a determination 
from ATF as to whether a particular firearm is subject to regulation 
using the procedure provided in this rule.
m. Definition of ``Importer's or Manufacturer's Serial Number''
Comments Received
    A few commenters stated that the new definition of ``importer's or 
manufacturer's serial number,'' which requires more information than 
under the current regulatory scheme, is confusing. They stated the term 
``identification number,'' which is part of the definition of 
``importer's or manufacturer's serial number,'' is not a defined term, 
though it seems to be referring to what the industry understands to be 
an identification number. They pointed out the term ``serial number'' 
is interchangeably used throughout the NPRM in different sections to 
mean both the identification number and the newly defined term.
Department Response
    The Department agrees with these commenters that clarification 
should be made to the definition of ``importer's or manufacturer's 
serial number.'' First, the Department recognizes the confusion that 
could be generated because the proposed definition of ``importer's or 
manufacturer's serial number'' stated: ``When used in this part, the 
term `serial number' shall mean the `importer's or manufacturer's 
serial number,' '' while other parts of the proposed marking 
requirements in Sec. Sec.  478.92 and 479.102 used the term ``serial 
number'' to also refer to a number that would be placed after an FFL's 
abbreviated license number. For this reason, the final rule clarifies 
the definition by defining it as the serial number placed by a licensee 
on a firearm, including any full or abbreviated license number, any 
such identification on a privately made firearm, or a serial number 
issued by the Director. It also specifies that, for purposes of 18 
U.S.C. 922(k) and 27 CFR 478.34, the term shall include any associated 
licensee name or licensee city or State placed on a firearm. The 
inclusion of the serial number and the associated licensee's 
information as part of this definition means that these markings are 
protected by 18 U.S.C. 922(k), which prohibits possession of a firearm 
with a removed, obliterated, or altered serial number.
    Because licensees have the option of marking the frame or receiver 
with either (1) a serial number and the manufacturer's or importer's 
city and State, or (2) a serial number beginning with its abbreviated 
license number and its name (or recognized abbreviation),

[[Page 24702]]

the final rule also makes minor changes in Sec. Sec.  478.92(a) and 
479.102(a). Specifically, in clarifying how a serial number may begin 
with an abbreviated license number as a prefix, these sections use the 
term ``unique identification number'' to properly describe the 
identifying information that would follow an FFL's abbreviated license 
number or an identification number placed by the maker of a PMF. 
Further, the rule also makes clear that the identification markings 
(including any unique identification number) must be ``legible,'' 
meaning that they must use exclusively Roman letters and Arabic 
numerals, or solely Arabic numerals.
    Also, to avoid confusion in the regulations with the ``serial 
number'' marked on a firearm, the term ``transaction number'' was 
substituted for ``serial number'' when explaining: (1) How Federal 
Firearm License numbers are assigned in Sec.  478.47(a); and (2) how 
ATF Forms 4473 may be ordered and recorded in Sec. Sec.  478.122(b), 
478.123(b), and 478.125(e). This will ensure that the sequential number 
stated on the FFL or Form 4473 will not be confused with the ``serial 
number'' marked on a firearm. Future versions of Form 4473 will reflect 
this change to the regulations.
n. Definition of ``Gunsmith''
Comments Received
    Several commenters who identified as gunsmiths expressed concern 
about ATF Ruling 2010-10 being superseded upon the effective date of 
the final rule. ATF Ruling 2010-10 allows Type 01 gunsmiths to perform 
various services for manufacturers and importers without needing to 
mark the firearm (or frame or receiver) per 27 CFR 478.92. The 
commenters stated that, once Ruling 2010-10 is superseded, gunsmiths 
would have to apply for a Type 07 manufacturer's license if they want 
to continue performing services for manufacturers. One custom gunsmith 
of 1911s provided an example of how the process of marking frames would 
be overly complex, if not impossible, to comply with if Ruling 2010-10 
were to be superseded. First, the frame (e.g., a 1911 frame) would have 
the original manufacturer's marking; then, as the builder of the custom 
pistol, the commenter would place his company's markings on the frame 
or receiver; then the markings of the Type 07 licensee that provides 
the checkering would be applied; and finally the markings of the Type 
07 licensee that provides the specialized finish would be applied. 
These commenters asked that ATF reconsider superseding Ruling 2010-10 
or provide an exemption to allow custom gunsmiths and firearms 
manufacturers to use each other's services in the manufacturing process 
without a requirement to mark, provided that the frame or receiver, as 
machined, is marked and compliant before the outside service is 
provided.
    Similarly, one manufacturer said the proposed definition of 
gunsmiths is underinclusive because it would allow gunsmiths to perform 
their services ``on existing firearms not for sale or distribution by a 
licensee.'' The manufacturer stated that the proposed change would 
preclude some Type 01 licensed gunsmiths from continuing to perform 
manufacturing activities on the manufacturer's behalf because those 
firearms will ultimately be intended for sale and distribution by the 
manufacturer. The manufacturer stated that this will impact several 
production lines at all of its primary manufacturing facilities. 
Another commenter stated that the proposed change to ``gunsmith'' 
implies that a person who is not a gunsmith would be prohibited from 
engraving a serial number onto the firearm. He stated that, if a person 
makes a PMF, that person should be able to serialize it.
Department Response
    The Department agrees that the new definition of ``gunsmith'' will 
result in the re-licensing of many gunsmiths as manufacturers when they 
are involved in the production of firearms for sale or distribution by 
licensees. This is because persons engaged in the business of 
manufacturing firearms (i.e., frames or receivers or complete weapons) 
for the purpose of sale or distribution by completing, assembling, 
applying coatings, or otherwise making them suitable for use, are 
required to be licensed as manufacturers. See 18 U.S.C. 921(a)(10), 
(a)(21)(A), 923(a). This is made clear in the revised definition of 
``gunsmith'' in the final rule.
    Nevertheless, in light of commenters' concern regarding the 
differences between gunsmithing and manufacturing, the final rule also 
makes clear that licensed dealer-gunsmiths are not required to be 
licensed as manufacturers if they perform gunsmithing services only on 
existing firearms for their customers or for another licensee's 
customers because the work is not being performed to create firearms 
for sale or distribution. The firearm upon which the gunsmithing 
service was performed is merely being returned to the individual from 
whom it was received.\129\ These services may include customizing a 
customer's complete weapon by changing its appearance through painting, 
camouflaging, or engraving; applying protective coatings; or by 
replacing the original barrel, stock, or trigger mechanism with drop-in 
replacement parts. Licensed dealer-gunsmiths may also purchase complete 
weapons, make repairs (e.g., by replacing worn or broken parts), and 
resell them without being licensed as manufacturers. Likewise, under 
the final rule, licensed dealer-gunsmiths may make such repairs for 
other licensees who plan to resell them without being licensed as a 
manufacturer. They may also place marks of identification on PMFs they 
may purchase and sell, or under the direct supervision of another 
licensee in accordance with this rule.
---------------------------------------------------------------------------

    \129\ As noted in the NPRM, this rule, consistent with Sec.  
478.124(a), does not require completion of an ATF Form 4473 or NICS 
background check when a PMF is marked as a firearm `customization' 
when it is returned to the person from whom it was received. 86 FR 
at 27731.
---------------------------------------------------------------------------

    These activities are distinguished from persons who engage in the 
business of completing or assembling parts or parts kits; applying 
coatings; or otherwise producing new or remanufactured firearms (frames 
or receivers or complete weapons) for sale or distribution. Such 
persons must be licensed as manufacturers. See, e.g., Broughman v. 
Carver, 624 F.3d 670, 676-77 (4th Cir. 2010), cert. denied, 563 U.S. 
1033 (2011) (licensed gunsmith who built and sold ``custom'' bolt 
action rifles by purchasing actions (receivers with internal parts) and 
barrels, fitting the barrels to the actions, bluing the actions, and 
making and attaching wooden stocks, was required to be licensed as a 
manufacturer).
    The Department also agrees that superseding ATF Ruling 2010-10 by 
this rule could be burdensome to licensed gunsmiths required to be 
licensed as manufacturers because they would now be required to place 
their own identifying marking on firearms already marked by a licensed 
manufacturer or importer. For this reason, this rule as finalized 
allows licensed manufacturers, including persons formerly licensed as 
dealer-gunsmiths, to adopt the serial number and other identifying 
markings previously placed on a firearm by another licensed 
manufacturer without a variance, provided that the firearm has not been 
sold, shipped, or otherwise disposed of to a person other than a 
licensee. This change will also reduce the potential for confusion by 
law enforcement when tracing a firearm

[[Page 24703]]

involved in a crime if multiple markings were to be found on those 
firearms. Under these circumstances, there is a reduced concern that a 
trace could not be successfully completed because the required records 
maintained by those licensees would reveal a continuous acquisition and 
disposition of that firearm.
    However, once a firearm is sold, shipped, or otherwise disposed of 
to a person other than a licensee, the trace can be completed only to 
the first retail purchaser. After that point, it is difficult to trace 
the firearm to another licensed manufacturer that may have purchased it 
for remanufacture and resale or redistribution without the purchaser's 
own identifying markings. For this reason, the final rule distinguishes 
between licensee adoption of markings on new firearms from those that 
were already introduced into commerce to nonlicensees, such as those 
that are being remanufactured or imported. Additionally, the final rule 
also allows licensed gunsmiths and licensed manufacturers that conduct 
gunsmithing activities to adopt the existing markings on firearms when 
they engage in gunsmithing activities on firearms that are not for sale 
or distribution. These changes will thereby supersede ATF Rulings 2009-
5 and 2010-10. Further, the final rule expressly clarifies that 
licensed manufacturers and importers, which are permitted to act as 
licensed dealers without obtaining a separate dealer's license (see 27 
CFR 478.41(b)), can perform adjustments or repairs on firearms for 
their customers without recording an acquisition, provided the firearm 
is returned to the person from whom it was received on the same day.
    Finally, with regard to PMFs, the Department agrees that licensed 
dealer-gunsmiths and other licensees that accept PMFs into inventory 
should be allowed to adopt a unique identification number placed by a 
nonlicensee if that identifying number otherwise meets the marking 
requirements. This allowance is reflected in the final rule. However, 
those licensees would still be required to place their abbreviated 
license number as a prefix (followed by a hyphen) to the existing 
serial number so that the firearm can be traced to them. Overall, the 
Department believes these provisions of the rule as finalized will 
mitigate the marking burden on licensees and make it easier for them to 
purchase and sell PMFs while maintaining traceability for law 
enforcement.
4. Concerns With Marking Requirements for Firearms
a. Information Required To Be Marked on Firearms
Comments Received
    Numerous commenters, including retailers and manufacturers, 
objected to the new marking requirements on multiple frames or 
receivers or on PMFs, arguing that the requirements would be too 
burdensome and confusing. Several manufacturers raised questions about 
what would be required of them. Some expressed confusion as to whether 
manufacturers and importers are to mark multiple parts of a single 
weapon with different serial numbers or if they are to mark separate 
components of a single weapon with the same serial number. Others asked 
if manufacturers of a present split or modular firearm configuration 
would continue to mark only the part they presently mark or if the NPRM 
would require them to mark more than one part until they receive a 
classification.
    Another manufacturer observed that, if a single firearm will have 
two or more frames or receivers, the manufacturer will produce and 
serialize them as separate parts, at different times, in different 
production lines. Each separate part will be a separate ``firearm,'' 
and the serial number on each will duplicate the serial number on 
other(s) until they are put together. These separate ``firearms'' may 
sit in different bins until assembled, all the while continuing to have 
duplicate serial numbers, thus violating the regulation against 
duplicate serial numbers. See 27 CFR 479.102(a)(1). There is also a 
risk, the manufacturer stated, that frames or receivers with different 
serial numbers could be mixed up during production or distribution, or 
even by the end user, resulting in firearms with two different serial 
numbers. At least one manufacturer did not understand why the rule 
would require manufacturers to mark the caliber and model on more than 
one frame or receiver if, in the alternative, this marking could 
otherwise appear solely on the barrel or pistol slide (if applicable).
    Another manufacturer stated that, although it is technically 
possible to serialize more than one part, for a small manufacturer to 
coordinate all of these components into batches for the various models 
and configurations with machine-engraved numbers would be challenging 
and very expensive. The manufacturer pointed out that, if all items are 
marked in advance and any one part fails a quality control process, it 
would lose the value of all three components and the manufacturer's 
scrap costs would increase significantly.
    Commenters asserted that, in the case of modular-type weapons, such 
as existing AR-15s, owners would be required to place serial numbers on 
parts that did not previously require them or would be prevented from 
swapping out upper and lower receivers, which is commonly done by 
firearms owners. Similarly, another commenter said that, without 
limiting the fire control components, videos show that 16 items in a 
typical Glock semiautomatic pistol would each be considered a frame or 
receiver and thus each part would need to be serialized and tracked. 
Others asked if there would be a controlling serial number for the 
firearm in the event that serialized parts are exchanged and a firearm 
has more than one serial number.
    Additional commenters worried that the new definitions and marking 
requirements make transfer and background checks of firearms very 
confusing and potentially costly. Commenters argued that, even if a 
consumer thinks that he or she is purchasing only one firearm, the 
reality is that a firearm with numerous serial numbers would need 
separate background checks, which in some States would mean additional 
fees. Further, others argued that this would create a mess for 
recordkeeping and trigger multiple sales reporting. They stated that, 
if a firearm has multiple frames or receivers, each part with a 
different serial number is a ``firearm'' unto itself. They questioned 
whether an FFL selling this type of firearm(s) would list several 
serial numbers on the ATF Form 4473 or whether the consumer would have 
to fill out more than one ATF Form 4473. In these types of scenarios, 
they questioned whether an FFL would be required to file a multiple 
handgun sales report or for--those retailers in the States of Texas, 
New Mexico, Arizona, and California--fulfill the multiple rifle 
reporting requirement. Others argued that the NPRM did not address 
States where residents are limited to purchasing one handgun a month. 
They argued that, if a firearm has multiple frames or receivers, each 
of which is a firearm by law, then individuals could be prevented from 
buying a handgun in States with these limitations.
    Another issue that several commenters raised is that they would not 
be able to fit all the new information on certain parts that will now 
be considered frames or receivers. For example, they stated that the 
NPRM requires serial number of an internal or drop in chassis frame or 
receiver (e.g.,

[[Page 24704]]

P320-type) to be unobstructed to the naked eye. The commenters said it 
is unclear how a manufacturer can safely place a lengthy abbreviated 
FFL number and the other requirements in the ``window'' of the polymer 
frame pistol so that the required information is visible. They stated 
that the inability to fit the new marking requirements is even more 
acute on smaller pistols or on certain curio and relic bolt action 
firearms.
    Another manufacturer said that it would need to design and acquire 
dozens of new molds to fulfill the new requirements for marking and 
that a typical mold costs approximately $100,000. The manufacturer 
stated it also would need to essentially modify all molds for polymer 
grip frames with the expanded marking requirements (such as by 
measuring from the flat surface of the metal and not the peaks or 
ridges, and by ensuring the markings are not susceptible to 
obliteration). This manufacturer also inquired how FFLs are supposed to 
measure the depth of markings after certain coatings are applied. 
Assuming the grip frames and trigger assembles will be frames or 
receivers under the NPRM, the manufacturer stated that it would have to 
modify each grip frame or trigger assembly to include a metallic plate 
suitable for marking a serial number, which would increase the costs 
for itself and suppliers of these parts, and also require it to obtain 
a marking variance.
    With regard to the content of the markings, one commenter wrote 
that the preamble of the NPRM contemplates that the new marking 
requirement could be satisfied by solely marking the licensee's name 
and RDS code plus a unique number (``RDS+'') and that the RDS+ would 
satisfy the unique ``serial number'' requirement. The commenter 
expressed confusion because the preamble indicates that the RDS+ suffix 
could include alphabetic characters, but the rule, despite defining 
``legibly,'' seems to limit the suffix to numerals only, as the rule 
uses the term ``number'' in several sections, such as Sec.  
479.102(a)(1). The commenter indicated that the contradictory 
information between the explanation in the preamble and the regulatory 
text itself is problematic because almost all manufacturers use 
alphabetic characters in their serial numbers. Other commenters pointed 
out that a modular lower can have its caliber changed and that, absent 
an upper, there is no way a manufacturer can mark a weapon with its 
caliber. They stated that the caliber should not be required on modular 
type weapons. They also asserted that requiring the caliber to be 
marked would be futile because owners can simply change the caliber by 
replacing the upper.
Department Response
    As stated previously, the Department agrees with numerous 
commenters that there should be only one ``frame or receiver'' in a 
given weapon or device. The Department has, therefore, added a new 
definition of ``frame or receiver'' in 27 CFR 478.11 and 479.11, as 
described herein, that focuses on one housing or structural component 
of a particular fire control or internal sound reduction component for 
a given weapon or device. Because of these revisions, there would 
almost always be one unique serial number marked on any such weapon or 
device, even if the components of a split or modular weapon were 
removed and reassembled using different components. To ensure that 
industry members and others can rely on ATF's prior classifications, 
almost all classifications and variants thereof have been grandfathered 
into the definition of ``frame or receiver.'' Frame or receiver designs 
that have been grandfathered under the definitions may continue to be 
marked in the same manner as before the effective date of the final 
rule. This change should address concerns raised by manufacturers that 
their costs would increase in order to mark their existing frames or 
receivers with the new marking requirements or to record multiple 
markings in connection with complete weapons or complete muffler or 
silencer devices, and by retailers that would have been required to run 
more background checks for more items classified as the ``frame or 
receiver'' under the rule as proposed.
    In response to comments on the content of the markings, the 
Department agrees with the comment that there could be confusion in the 
regulatory text as to the ``number'' that must be marked after the RDS 
Key, described in the rule as the licensee's abbreviated Federal 
firearms license number. For this reason, the regulatory text has been 
amended to change the word ``number'' to ``unique identification 
number'' in Sec. Sec.  478.92(a) and 479.102(a), where appropriate, to 
ensure that this particular marking is part of the ``serial number'' in 
that scenario. The unique identification number may include both 
alphabetic and numeric characters as stated in the definition of 
``legibly.''
    The Department disagrees with the comment saying that caliber or 
gauge should not be a required marking for split or modular weapons. 
Information concerning the caliber or gauge of a weapon is useful to 
distinguish between firearms during a trace or when matching 
projectiles to a particular weapon found at a crime scene. To mitigate 
the problem raised by commenters that a modular weapon's caliber can 
change, the final rule makes clear the model designation and caliber or 
gauge may be omitted if that information is unknown at the time a frame 
or receiver is sold, shipped, or otherwise disposed of separately from 
the complete weapon or complete muffler or silencer device.
b. Markings on ``Split or Modular Frames or Receivers''
Comments Received
    Some manufacturers asked how they would handle warranty repairs of 
a modular or split receiver firearm under the NPRM if one of the marked 
parts must be replaced to make the firearm safe to use. They stated 
that a manufacturer would not be able to provide a replacement part 
because it cannot reuse the serial number or return the firearm with 
unmarked component(s) that are now considered to be the frame or 
receiver. If they did, the replacement part would be marked with a 
different serial number, placing the manufacturer in violation of 
section 923(i) of the GCA. They also asked if disassembly (e.g., 
routine cleaning or replacement or repair of a part ATF would classify 
as frame or receiver) would constitute removal of the manufacturer or 
importer serial number in violation of 18 U.S.C. 922(k).
Department Response
    Unlike the proposed rule, this final rule does not require multiple 
parts of a split frame or receiver to be marked (i.e., only the upper 
receiver of a split receiver rifle need be marked, unless the lower is 
the grandfathered part). Thus, non-serialized parts of a split frame or 
receiver may be replaced without violating section 923(i). However, the 
final rule explains that similar modular subparts of a ``multi-piece 
frame or receiver'' (e.g., two similar left and right halves of a frame 
or receiver) must be marked with the same serial number and associated 
licensee information. If one of those parts is removed and replaced 
with an unserialized part, then the possessor would violate section 
922(k) for possessing a firearm with a removed serial number. However, 
the final rule sets forth a process by which a marked modular subpart 
of a non-NFA multi-piece frame or receiver may be removed and replaced 
without violating section 922(k). The replacement modular subpart must 
be marked by its manufacturer with the same original

[[Page 24705]]

serial number and associated licensee information, and the original 
part must be destroyed prior to such placement.
    More specifically, under 18 U.S.C. 923(i) and 26 U.S.C. 5842(a), 
ATF has the authority to prescribe by regulations the manner in which 
licensed manufacturers and importers (and makers of NFA firearms) must 
identify a serial number on the frame or receiver of a weapon. Because 
multi-piece frames or receivers may be partitioned into similar modular 
subparts that could be produced and sold separately, each subpart must 
be identified with the same serial number and associated licensee 
information so that the frame or receiver, once complete (assembled or 
unassembled), can be traced to its manufacturer. The serial number 
identified on each subpart must be the same number so that the complete 
frame or receiver does not have a serial number duplicated on any other 
firearm produced by the manufacturer. Once the modular subparts are 
aggregated as a complete multi-piece frame or receiver, a modular 
subpart identified with the serial number cannot be removed and 
replaced unless the destruction procedure set forth in this rule is 
followed. See 18 U.S.C. 922(k); 27 CFR 478.34 (prohibiting possession 
or receipt of a firearm that has had the importer's or manufacturer's 
serial number removed); see also 26 U.S.C. 5861(g), (h) (prohibiting 
removal of the serial number or possession of an NFA firearm from which 
the serial number has been removed).\130\
---------------------------------------------------------------------------

    \130\ Cf. United States v. Mixon, 166 F.3d 1216 1998 WL 739897, 
at *3 (6th Cir. 1998) (table) (``The fact that the entire serial 
number or other indications of the serial number on the weapon were 
not obliterated fails to negate the fact that a portion of the 
serial number had been obliterated.''); United States v. Frett, 492 
F. Supp. 3d 446, 4552 (D.V.I. 2020) (``[T]he Court holds that a 
firearm bearing multiple serial numbers, only one of which is 
removed, `has had the importer's or manufacturer's serial number 
removed, obliterated, or altered' within the meaning of Section 
922(k).'').
---------------------------------------------------------------------------

c. Size and Depth of Markings
Comments Received
    Another issue raised by commenters is the feasibility of doing an 
engraving to meet the new size specifications. One organization stated 
that, currently, the print size and depth limitations pertain only to 
serial numbers and not the additional information (i.e., manufacturer's 
or importer's city or State). The proposed change to require that the 
serial number and additional information be engraved to a minimum depth 
of .003 inches and in a print size no smaller than 1/16 inch, per the 
proposed Sec.  478.92(a)(i)(iv), would assertedly make it difficult or 
impossible to comply.
Department Response
    The Department agrees with this comment, and as stated in the 
preamble of the proposed rule, this rule would not change the existing 
requirements for size and depth of markings. Consequently, the text of 
this paragraph in the final rule is amended to clarify that only the 
serial number and any associated license number must be in a print size 
no smaller than \1/16\ inch.
d. Period of Time To Identify Firearms
Comments Received
    Some commenters were concerned that the seven-day time limit in the 
proposed rule for qualified manufacturers to identify NFA firearms 
contradicts existing law because ATF Form 2, Notice of Firearms 
Manufactured or Imported, must be filed by the close of the next 
business day after manufacture, pursuant to 27 CFR 478.103. Accord 
United States v. Walsh, 791 F.2d 811, 818 (10th Cir. 1986) (``The 
registration procedure for manufactured firearms contained in the 
Treasury regulation does not provide additional time within which to 
place a serial number on a firearm.''). One of these commenters was 
also concerned that the term ``active manufacturing process'' for 
purposes of applying the seven-day time limit was vague because a 
suppressor may be functional in some capacity even if the manufacturer 
is waiting for additional baffles to replace damaged or incorrectly 
manufactured parts that were previously produced.
Department Response
    The Department agrees with these commenters that the proposed 
seven-day time limit to mark NFA firearms is inconsistent with the 
``close of next business day'' filing requirement for ATF Form 2, which 
must include the serial number of the firearms manufactured. For this 
reason, the final rule makes clear that weapons and parts defined as 
``firearms'' only under the GCA, but not the NFA, must be identified 
not later than the seventh day following the date the entire 
manufacturing process has ended for the weapon (or frame or receiver, 
if disposed of separately), or prior to disposition, whichever is 
sooner. Weapons and parts defined as ``firearms'' produced under the 
NFA must be marked by close of the next business day. In this way, the 
marking requirements under the GCA or NFA will be consistent with their 
applicable recordkeeping requirements, while providing reasonable grace 
periods in which to identify firearms after the entire manufacturing 
process has ended.
    The Department also believes that the phrases ``actively awaiting 
materials'' and ``completion of the active manufacturing process'' 
should be made clearer in the final rule. For this reason, the final 
rule no longer uses the term ``actively awaiting materials'' and 
instead establishes a presumption that firearms awaiting materials, 
parts, or equipment repair to be completed are, absent reliable 
evidence to the contrary, in the manufacturing process. The final rule 
also substitutes the phrase ``completion of the active manufacturing 
process'' for ``the entire manufacturing process has ended'' in 
determining the applicable time limit to identify firearms.
e. Marking ``Privately Made Firearms''
Comments Received
    Numerous commenters objected to the requirement that PMFs be 
serialized. Many believed that the proposed rule would require makers 
of PMFs that are non-NFA weapons to serialize their firearms and 
emphasized that it should be optional, not required, for a person to 
serialize the person's own guns. They asserted that holding private 
individuals to the same standards as commercial or corporate FFLs is 
unreasonably burdensome. Others pointed out that most PMFs are made 
from polymer or plastic and that there is no way to insert a piece of 
metal, which would be required per the proposed regulations, unless 
they go to a dealer or gunsmith and pay for extensive modifications. 
Commenters also said that forcing dealers to mark PMFs with their 
license information simply because a PMF owner took a firearm in for 
repair or upgrade is an added cost because the dealers will have to 
obtain additional equipment that is not needed for their daily 
operations and could be subject to liability if their FFL information 
is attached to a PMF. Commenters also asserted that PMF owners would 
not want their PMFs marked and that the rule would therefore prevent 
them from getting their PMFs repaired by FFLs or gunsmiths.
    With respect to marking PMFs, commenters claimed that it would not 
be reasonable to expect an FFL retailer to know how to safely serialize 
a custom PMF because the safety of the firearm could be compromised if 
markings are placed in critical areas. Moreover, commenters said that 
many FFLs will not have the capability to mark firearms with serial 
numbers and thus would not be able to acquire and ship non-serialized 
PMFs to other dealers for

[[Page 24706]]

customers. Manufacturer FFLs and trade organizations similarly stated 
that PMFs are not subject to the same quality control as commercial 
arms and that FFLs would face more liability if they ran into problems 
adding a serial number to a customized PMF.
    Other commenters discussed the burden associated with requiring 
PMFs to be marked any time one is received into inventory even if it is 
received for purposes limited to activities such as bore sighting or 
onsite adjustments at sporting events. The commenters stated that an 
FFL would not be able to perform a function test or other quick 
gunsmithing without first recording it in the A&D records and adding a 
serial number. Another commenter asked if an FFL would have to re-
serialize a PMF if the PMF had already been marked with the private 
builder's own serial number. The commenter asserted it would be better 
for ATF to provide a best practices recommendation as to how FFLs may 
mark a PMF rather than making it a mandatory regulation. In addition, 
one commenter believed that one implication of the rule is that makers 
of PMFs would not be able to serialize their own PMFs because only FFLs 
would be able to serialize them.
    Commenters also stated the marking requirement seems to require the 
use of laser, engraving, or CNC mill machines with engraving 
capabilities, given the mandatory depth and size requirements, which 
comments said could not be satisfied with simple and cheap engraving 
tools. Also, specifically with respect to PMFs, one FFL/SOT holder 
stated that metal plates on common polymer PMFs are often not large 
enough to engrave the proposed 10-plus character number to ATF size 
requirements. The suggestion from ATF in the NPRM that FFLs embed metal 
plates into PMFs, according to the commenter, does not comprehend the 
variety of materials--including epoxies, resins, ceramics, thermoset 
plastics, and well-known materials such as Bakelite--that do not allow 
for doing so.
    A few commenters asserted that seven days is not sufficient time 
for FFLs to mark PMFs. Some argued there is no realistic way to mark a 
PMF in seven days because extra time would be needed to disassemble a 
completed PMF to mark it properly; or, if the FFL had no resources to 
engrave a serial number, then the FFL would have to send it out for 
marking, and it would be unlikely that the firearm could be marked 
within that time period if businesses that can do the marking have a 
backlog of work. Similarly, commenters argued that requiring FFLs to 
mark, or supervise the marking of, serial numbers of PMFs in their 
inventory within a seven-day period would severely interrupt FFLs' 
ability to conduct such business and they would likely turn away 
unmarked PMFs to avoid these burdensome regulatory requirements. Others 
argued that the period of time should be extended to 21 days to account 
for delays, which could be caused by weather, fuel shortages, or 
shipper incompetence when shipping PMFs to another licensee, such as a 
gunsmith, for marking.
Department Response
    As an initial matter, the Department notes that nothing in this 
rule requires private individuals to mark their personally made (non-
NFA) firearms or to present them to licensees for marking. Nothing in 
this rule requires licensees to accept PMFs into inventory, mark PMFs 
with the name of the private maker, or record the maker's name as the 
``manufacturer'' of the firearm. This rule requires only that PMFs 
voluntarily taken into inventory by FFLs be marked with a serial number 
prefixed with the licensee's abbreviated license number and for the FFL 
to record the acquisition information. This requirement allows the PMF 
to be traced directly to the licensee, not the private maker, if later 
used in a crime.
    This rule explains in detail how accepting PMFs into inventory 
without serial numbers undermines the entire purpose of maintaining 
transaction records and other required records. For example, if 
multiple unmarked PMFs of the same ``type'' are accepted into 
inventory--each recorded only as a ``pistol''--they would be 
indistinguishable from each other for tracing and other law enforcement 
purposes. Even if a PMF could be traced to a particular firearms 
licensee, there would be no information marked on that weapon that 
could be matched to a specific recordkeeping entry in either the 
acquisition or disposition book, ATF Form 4473, theft/loss report, or 
multiple sales report. For these reasons, PMFs must be marked with a 
traceable serial number like other firearms, but they do not need to be 
marked with the name of the private maker. As the proposed rule 
explained, PMFs would typically be marked by permanently embedding a 
metal plate into the polymer. 86 FR at 27732. Many, if not most, PMF 
parts kits already have a metal plate embedded into the partially 
complete frame or receiver for serialization purposes and to assist 
purchasers in complying with some State, local, or international 
laws.\131\ If a licensee does not have the capability to mark, the 
licensee can arrange for private individuals to have the PMFs marked by 
another person before accepting them, or, after acceptance, arrange for 
PMFs to be marked under the licensee's direct supervision with the 
licensee's serial number.
---------------------------------------------------------------------------

    \131\ The European Union (EU), for example, has issued a 
directive specifying how member countries are to mark polymer frames 
or receivers: ``For frames or receivers made from a non-metallic 
material of a kind specified by the Member State, the marking is 
applied to a metal plate that is permanently embedded in the 
material of the frame or receiver in such a way that: (a) The plate 
cannot be easily or readily removed; and (b) removing the plate 
would destroy a portion of the frame or receiver. Member States may 
also permit the use of other techniques for marking such frames or 
receivers, provided that those techniques ensure an equivalent level 
of clarity and permanence for the marking.'' Commission Implementing 
Directive (EU) 2019/68 of 16 January 2019 Establishing Technical 
Specifications for the Marking of Firearms and Their Essential 
Components Under Council Directive 91/477/EEC on Control of the 
Acquisition and Possession of Weapons, annex.
---------------------------------------------------------------------------

    The Department also disagrees that metal serial number plates 
cannot be embedded or overprinted \132\ into polymer materials, or that 
the serial number plates currently embedded within polymer frames or 
receiver are not or cannot be made large enough to be marked with at 
least 10 characters at the minimum \1/16\-inch print size. The 
Department further believes that, as technology develops, it will 
become easier and cheaper for licensees to embed metal plates into 
polymer materials. Although, upon issuance of this rule, it may be 
difficult for licensees to mark some PMFs that they might have taken 
into inventory (i.e., those without previously embedded serial number 
plates), the Department believes the final rule provides a sufficiently 
long grace period for them to mark or arrange for them to be marked by 
another licensee. Specifically, licensees will have from the date the 
final rule is published until 60 days after the effective date to 
properly mark and identify PMFs as required by the regulations.
---------------------------------------------------------------------------

    \132\ See footnote 69, supra.
---------------------------------------------------------------------------

    Nonetheless, the Department agrees with some commenters that 
licensees, including dealer-gunsmiths, should be allowed to adopt a 
unique identification number previously placed on a PMF by a private 
maker that is not duplicated on another firearm of the licensee and 
otherwise meets the identification requirements of this section 
provided that, within the period and in the manner herein prescribed, 
the licensee legibly and conspicuously places, or causes to be placed, 
on the frame or receiver thereof the licensee's own

[[Page 24707]]

abbreviated Federal firearms license number, which is the first three 
and last five digits, followed by a hyphen, before the existing unique 
identification number, e.g., ``12345678-[unique identification 
number].'' Again, these markings will allow the PMF to be traced to the 
licensee if later recovered at a crime scene.
    Finally, the Department agrees with the comment that dealer-
gunsmiths, as well as licensed manufacturers and importers, should be 
allowed to perform a function test and quick repairs on a PMF. For this 
reason, the final rule clarifies that licensed dealer-gunsmiths, 
manufacturers, and importers may conduct same-day adjustments or 
repairs on PMFs without having to place identifying markings or record 
the receipt as an acquisition or subsequent disposition upon return. 
This is not a significant change from the proposed rule because it 
provides consistency for same-day adjustment or repair by treating PMFs 
the same as commercially produced firearms in that they must be 
recorded in inventory only if repaired overnight. ATF has long 
maintained that, if a firearm is brought in for adjustment or repair 
where the person waits while it is being adjusted or repaired, or if 
the gunsmith is able to return the firearm to the person during the 
same business day, it is not necessary to list the firearm in the 
gunsmith's A&D records as an ``acquisition.'' \133\ If the gunsmith has 
possession of the firearm from one day to another or longer, the 
firearm received by the gunsmith must be recorded as an ``acquisition'' 
and then as a ``disposition'' in the gunsmith's A&D records upon return 
to the same customer. However, the final rule makes clear that a PMF 
must be recorded as an acquisition whenever it is marked for 
identification, including same-day or on-the-spot. The only exception 
is when the firearm is marked by another licensee under the licensee's 
direct supervision with the licensee's serial number because the 
firearm has already been recorded as an acquisition.
---------------------------------------------------------------------------

    \133\ See ATF Rul.77-1 (holding that a firearm need not be 
entered into the bound A&D record if the firearm is brought in for 
adjustment or repair and the customer waits while it is being 
adjusted or repaired, ``or if the gunsmith returns the firearm to 
the customer during the same business day it is brought in,'' but 
noting that, if the '' the firearm is retained from one business day 
to another or longer, it must be recorded in the bound acquisition 
and disposition record''); ATF, Does a gunsmith need to enter every 
firearm received for adjustment or repair into an acquisition and 
disposition (A&D) record? (July 13, 2020), available at https://www.atf.gov/firearms/qa/does-gunsmith-need-enter-every-firearm-received-adjustment-or-repair-acquisition-and. This final rule 
clarifies ATF Rul. 77-1 by explaining that licensed manufacturers 
and importers, who may engage in the business as a licensed dealer 
without obtaining a separate license (see 27 CFR 478.41(b)), may 
also perform same-day adjustment or repair without an acquisition 
record entry.
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f. Adoption of Identifying Markings
Comments Received
    Some commenters stated that the explanation in the NPRM's preamble 
on the ``Marking of Privately Made Firearms'' indicated that FFLs must 
always mark PMFs upon acquisition even if the private maker has already 
added a serial number. Commenters stated that markings PMFs with a 
manufacturer's name, location, and a unique serial number is equivalent 
to the markings of a commercial firearm and therefore the regulation 
should account for PMFs already so marked. Similarly, they raised 
questions about the effect of the proposed rule for NFA firearms that 
have been approved through an ATF Form 1 and already recorded in the 
NFRTR. They asked if the original markings, as done by the maker of the 
firearm and recorded in the NFRTR, can be adopted by the FFL that 
acquires the PMF. Others asked whether the new marking requirements 
would render owners of pre-1986 machineguns, short-barreled rifles, 
short-barreled shotguns, and any other weapons under the NFA 
noncompliant with the NFA, as many of these firearms have only the 
lower receiver serialized and not other parts that could be deemed a 
frame or receiver under the NPRM.
Department Response
    The Department agrees with commenters who said that PMFs that were 
manufactured or ``made'' privately should be treated similarly to 
commercial firearms when they are received by FFLs. The Department 
therefore agrees that FFLs should be allowed to adopt a unique 
identification number on a PMF if it otherwise meets the marking 
requirements. This final rule allows such adoption as an exception. 
However, unlike commercially produced firearms, private makers are not 
required to maintain records of production and transfer, and, under the 
GCA, firearms involved in crime are traced to licensees, not private 
makers. For this reason, licensees wishing to adopt the unique 
identification number marked by a private maker on a PMF would still 
need to add their abbreviated license number as a prefix to the unique 
identification number so adopted. In that way, the firearm can be 
traced to a licensee.
    With regard to privately made NFA firearms, the rule as proposed 
and finalized does not define the term ``privately made firearm'' to 
include NFA firearms that have been identified and registered in the 
NFRTR pursuant to chapter 53, title 26, United States Code, or any 
firearm manufactured or made before October 22, 1968 (unless 
remanufactured after that date) that were not required to be marked. 
Furthermore, as stated previously, this rule requires marking only of a 
single component and grandfathers all prior ATF classifications except 
for partially completed, disassembled, or nonfunctional frames or 
receivers, including parts kits, that ATF determined were not firearm 
``frames or receivers'' as defined prior to this rule.
g. Marking of ``Firearm Muffler or Silencer Frame or Receiver''
Comments Received
    Numerous commenters asserted that silencers should not be regulated 
at all because they are used solely to protect a shooter's hearing by 
reducing the sound levels of firearms and do not make a firearm any 
more dangerous or affect the function of a firearm other than managing 
recoil. Therefore, they argued, there should be no requirement to mark 
or serialize these devices. They stated that almost no crimes outside 
of Hollywood movies are committed while using silencers and that 
unnecessary paperwork, taxes, wait times, and regulations have deprived 
firearm owners from obtaining a simple device that could help them 
avoid hearing loss. Others pointed out that there are a number of 
silencers without an outer tube, such as the Q erector, and there is no 
clear way to fit such a device within the proposed rule. They 
recommended the rule be more flexible by allowing for serialization 
requirements to be determined by the model of the silencer.
    The American Suppressor Association (``ASA'') referenced ATF's 
current guidance to industry that ``[t]he replacement of the outer tube 
is so significant an event that it amounts to the `making' of a new 
silencer.'' Accordingly, ASA pointed out that, under ATF's current 
guidance, the new silencer needs to be marked, registered, and 
transferred in accordance with the NFA and GCA. ASA asserted that this 
current guidance is unsupported by statute and should be addressed in 
the NPRM. ASA opined that remaking the outer tube for a silencer does 
not constitute the making of a new silencer under the NFA when such 
remaking is: (1) Completed by the original manufacturer of the silencer 
in question;

[[Page 24708]]

and (2) the remade outer tube is marked with the same serial number as 
the replaced outer tube. ASA asked that ATF allow for the replacement 
of a silencer's outer tube in these instances and opined that the 
NPRM's new definition of ``frame or receiver'' for silencers is a 
perfect forum for ATF to announce and codify this reconsideration.
Department Response
    The Department disagrees with comments that silencers should not be 
marked with serial numbers. Both the GCA and NFA regulate firearm 
mufflers and silencers as ``firearms.'' 18 U.S.C. 921(a)(3)(C); 26 
U.S.C. 5845(a)(7). The GCA and NFA require silencers, like other 
firearms, to be identified with a serial number, see 18 U.S.C. 923(i); 
26 U.S.C. 5842(a), and they could not be registered in the NFRTR 
without a serial number. This rule sets forth when and how silencers 
must be serialized. It makes it easier for manufacturers, importers, 
and makers to place serial numbers by requiring only one part of a 
complete firearm muffler or silencer device (i.e., the frame or 
receiver, as defined), to be marked and not the other silencer parts 
when transferred between qualified licensees for further manufacture or 
repair of complete devices.
    With respect to modular silencers like the Q erector, the final 
rule makes clear that, in the case of a modular firearm muffler or 
silencer device with more than one part that provides housing or a 
structure for the primary internal component designed to reduce the 
sound of a projectile (i.e., baffles, baffling material, or expansion 
chamber), the term ``frame or receiver'' means ``the principal housing 
attached to the weapon that expels a projectile, even if an adapter or 
other attachments are required to connect the part to the weapon.''
    The Department also does not agree with the comment that the final 
rule should allow for the replacement of a silencer's outer tube by its 
SOT manufacturer when the original tube is destroyed, and the 
replacement is marked with the original serial number. Under the NFA, 
26 U.S.C. 5841(b)-(c), each qualified manufacturer must register in the 
NFRTR each firearm it manufactures and notify ATF of such manufacture 
to effect the registration. ATF has taken the position that the 
replacement of a serialized outer tube, now defined as the frame or 
receiver, is such a significant manufacturing activity that it results 
in the manufacture of a new silencer for which notification is 
required. See ATF, National Firearms Act Handbook--Appendix B--
Frequently Asked Questions--Silencers at 175-76, available at https://www.atf.gov/files/publications/download/p/atf-p-5320-8/atf-p-5320-8.pdf. Additionally, unlike the return of an NFA firearm conveyed for 
repair, qualified manufacturers are required to pay transfer tax when a 
new silencer is transferred to an unlicensed person. See 26 U.S.C. 
5811. Therefore, allowing manufacturers to create and return new NFA 
firearms, including silencers, without notification to ATF or payment 
of transfer tax would be contrary to law.
h. Firearms Designed and Configured Before Effective Date of the Rule
Comments Received
    Numerous commenters expressed concern that the grandfathering 
provision regarding marking in the NPRM is unclear and that they would 
not know if the new marking requirements would be triggered without 
more clarity from ATF. Commenters pointed out that the NPRM says 
licensed manufacturers and importers may continue to identify the 
additional firearms (other than PMFs) of the same ``design and 
configuration'' as they existed before the effective date. They stated 
the use of ``and'' in this phrase indicates that both criteria must be 
met for the grandfathering clause to apply and thus they were uncertain 
when changes to a particular firearm model remove it from the 
grandfathering protection. One manufacturer stated that it routinely 
introduces new SKUs that differ from existing designs and 
configurations in minor ways. Likewise, others asked if a change in 
grip panels, barrel length, or fixed sights versus adjustable or red-
dot capable sights would result in a change in design or configuration. 
Accordingly, they requested that ATF give clarity to the terms 
``design'' and ``configuration'' as well as ensure that the current 
definition of frame or receiver is preserved for grandfathered firearms 
that will continue to follow the old marking requirements so as to 
avoid creating a third category of firearms that do not fit within 
either the old or new marking requirements. They also stated that they 
will face new burdens regarding future firearms designs and 
configurations without knowing the meaning of those terms.
    One trade group that represents importers stated that ATF needs to 
clarify whether its grandfather provision for marking means that all 
previously manufactured models and configurations are not required to 
be marked under the new requirements. Specifically, the group asked if 
firearms manufactured overseas before the publication of the rule, but 
imported afterwards, are exempt from the new requirements. If they are 
not exempt, the group stated, then an exemption should be drafted that 
allows the markings to be engraved on the barrel or slide when the 
receiver is too small to mark conspicuously. The group argued that 
simply allowing for this result by variances is inefficient.
    Another FFL said the rule does not address whether a manufacturer 
is supposed to mark, or register as acquired, parts already in its 
physical inventory if those parts now meet the new definition of frame 
or receiver when those parts are used in the assembly of a complete 
firearm that is of a new design or configuration. The FFL also stated 
it is unclear what serialization information should be put on ``newly'' 
defined frame or receiver parts that are vendor supplied but already in 
its inventory. Alternatively, it said, if serialization is not 
required, then the rule should address whether a licensee would be 
required to place the unserialized firearms in its A&D records with a 
serial number of ``No Serial Number'' (``NSN''). The FFL further 
pointed to extraneous impacts of the proposed definition and marking 
requirements, noting that manufacturers use outside, non-licensed 
vendors to supply numerous firearm components, many of which could fall 
under the definition of frame or receiver, thus forcing these vendors 
to become licensees and meet the new marking and recording 
requirements.
Department Response
    The Department agrees with commenters that the grandfathering of 
firearms should be clarified by ensuring that the current definition of 
frame or receiver is preserved for existing firearms and by clarifying 
the meaning of ``design and configuration'' in the proposed rule. In 
light of these comments, the final rule recognizes ATF's prior 
classifications identifying a specific component of a given weapon as 
``the'' frame or receiver, including variants thereof, as falling 
within the new definition of ``frame or receiver.'' Only ATF's prior 
determinations that a partially complete, disassembled, or 
nonfunctional frame or receiver, including a parts kit, was not, or did 
not include, a firearm ``frame or receiver'' as defined prior to this 
rule are excluded from the grandfathering clause. Such determinations 
include those in which ATF had determined that the item or kit had not 
yet reached a stage of

[[Page 24709]]

manufacture to be, or include, a ``frame or receiver'' under the 
existing definitions. Because this rule expressly regulates weapon and 
frame or receiver parts kits, and aggregations of parts with partially 
complete frames or receivers that are designed to, or may readily be 
converted to, expel a projectile, these prior ATF classifications (in 
which the entire kit may not have been presented to ATF at the time of 
classification) will need to be re-evaluated on a case-by-case basis.
    To address confusion concerning the meaning of ``new design and 
configuration,'' the final rule retains the marking grandfathering 
provision, but revises the text to remove ``and configuration'' and 
defines ``new design'' to mean ``that the design of the existing frame 
or receiver has been functionally modified or altered, as distinguished 
from performing a cosmetic process that adds to or changes the 
decoration of the frame or receiver (e.g., painting or engraving), or 
by adding or replacing stocks, barrels, or accessories to the frame or 
receiver.'' The Department considered commenters' concerns that the 
potential effect of the new rule to require new configurations of 
existing models to be marked under the new marking requirements would 
impose substantial costs (such as the cost of making new molds to 
conform with the new requirements) on existing product lines that are 
not otherwise being modified. ATF considered these comments in light of 
the public safety interest in ensuring appropriate markings. Because 
ATF has the capacity to successfully trace the many hundreds of 
thousands of grandfathered firearms and will be able to continue to 
trace them even if there is a change in configuration, the Department 
removed ``and configuration.'' The revised provision therefore allows 
manufacturers to mark the same information on the same component 
defined as a ``frame or receiver'' as they did before the effective 
date of the rule, which includes the specific component of a weapon or 
device (and variants thereof) that ATF classified as the frame or 
receiver before the rule becomes effective.
    In regard to the comment on how the rule applies to new designs of 
firearms already in inventory, the final rule makes clear that the new 
marking requirements apply only to frames or receivers manufactured 
after the effective date of the final rule. This change will help 
accommodate changes in firearms technology while still ensuring that 
the frames or receivers with new modular designs are marked and can be 
traced. The new marking information substantively differs from the 
current marking requirements for firearms (other than PMFs) only in 
that the licensee's name, city and State, or, alternatively, the 
licensee's name (or recognized abbreviation) and manufacturer's or 
importer's abbreviated FFL number, must be placed on the frame or 
receiver in addition to the unique identification number, and cannot be 
placed on the slide or barrel. The reason for requiring all this 
information to be placed on the frame or receiver is that the 
associated licensee information, when marked on the slide or barrel as 
currently allowed, can be separated from the serialized frame or 
receiver in limited circumstances, rendering the firearm untraceable. A 
unique identification number, or traditional serial number, on the 
frame or receiver alone may not be sufficient because ATF may not know 
which licensee produced the firearm or the location where the traceable 
records are located. Manufacturers may, however, seek a marking 
variance from the Director if they find it difficult to transition to 
these marking requirements for new frame or receiver designs.
i. Voluntary Classifications of Firearms and Armor Piercing Ammunition
Comments Received
    A few commenters said the way that Sec.  478.92(c) is drafted does 
not obligate ATF to respond to a classification request, which could 
allow the agency to ignore a classification request and stall 
advancement of new products or technologies deemed politically 
undesirable. Commenters also noted that there is no requirement that 
the agency notify the submitter that the agency has accepted or 
rejected the classification request. Therefore, the commenters 
advocated that there should be a requirement that determinations be 
rendered within three months or that some other reasonable time-frame 
be added to the proposed 27 CFR 478.92(c). One commenter suggested 
adding language deeming the submitted product compliant as proposed by 
the requestor if ATF fails to respond within a specified time frame. It 
also recommended deleting, for purposes of flexibility, the prohibition 
on rendering a determination unless a firearm accessory or attachment 
is installed on the firearm(s) for which it is designed and intended to 
be used. Further, it proposed adding a sentence stating that an ATF 
determination is an opinion and does not have the force of law. Another 
commenter claimed that the codification of the classification letter 
process fails to abide by the Attorney General's memorandum entitled 
``Prohibition on Improper Guidance Documents.''
    Commenters also said that it is unrealistic to believe that a 
manufacturer would have the ability to submit marketing or instruction 
materials with a classification request per the proposed rule, as 
oftentimes these materials are developed just before a product 
launches. They also questioned whether a prior determination becomes 
invalid if instructions or marketing materials change, thereby 
triggering submission of another request and reverting the product to 
the proposed rule's default marking requirements pending a new 
determination. Other commenters argued that asking manufacturers to 
submit instructions and manuals is not only a huge administrative 
burden but also would lead to less production and fewer submissions of 
instructions, as it seemed possible that ATF could use the guides 
against the manufacturers. The lengthy waits and delays that 
manufacturers already face under the current process, according to the 
commenter, would only be compounded under the NPRM. All this would have 
the unintended consequence of creating a disincentive for manufacturers 
to develop new, safer, and more reliable firearms because of a heavy 
regulatory burden.
    Some commenters further opined that ATF's classification process 
allows the agency to play favorites, pick technologies, and influence 
court decisions without going through the APA. They asserted that the 
proposed rule actually incentivizes technical developments that will 
create an even worse black market of untraceable firearms.
    One commenter suggested altering the last sentence of proposed 27 
CFR 478.92(c), to state that ATF classifications of frames or receivers 
issued after publication of the final rule are not considered 
authoritative with regard to other samples, designs, models, or 
configurations of frames or receivers. Adding this language, the 
commenter said, would allow a licensee to leverage a previous hardware 
determination and make it more transparent to industry that a previous 
hardware determination is an acceptable practice if the design was in 
existence prior to the publication date of the final rule.
Department Response
    The Department agrees with commenters that the rule, as proposed, 
would have resulted in more voluntary classification requests to ATF to 
determine which part of a new design

[[Page 24710]]

of a firearm was ``the'' frame or receiver. This would have increased 
the burden on both licensees and ATF. The Department agrees with 
commenters that the statute is best read to focus on a single portion 
of a weapon as ``the'' frame or receiver. Accordingly, the Department 
establishes a new definition of ``frame or receiver'' as described to 
focus on a single portion of a weapon for ``frames'' of handguns; 
``receivers'' for rifles, shotguns, and projectile weapons other than 
handguns; and ``frames'' or ``receivers'' for firearm muffler or 
silencers. The final rule does not adopt the proposed definitional 
supplement entitled ``Split or Modular Frame or Receiver.'' The 
Department agrees that not finalizing this provision will substantially 
reduce or eliminate the need for persons to submit classification 
requests to ATF to help them determine which portion of a weapon is the 
frame or receiver of a particular model.
    With regard to other types of firearm classification requests, ATF 
has long accepted voluntary requests in furtherance of its mission to 
assist persons in complying with the requirements of the GCA and NFA as 
a public service. There is no statutory requirement for a person to 
submit such requests and likewise no requirement for ATF to act upon 
any such requests. Alternatively, anyone may seek private counsel to 
determine the person's legal obligations under the Federal firearms 
laws and regulations.
    The Department disagrees with the suggestion to eliminate, for 
flexibility, the provision that states that the Director shall not 
issue a determination regarding a firearm which may be sold or 
distributed with an accessory or attachment unless it is installed on 
the firearm(s) in the configuration for which it is designed and 
intended to be used. The accessory or attachment itself must be 
attached to the weapon so that a proper firearm classification can be 
made under the GCA or NFA.
    The Department disagrees with the suggestion to add a sentence to 
individual ATF firearm classifications saying that the classification 
is an opinion that does not have the force of law. Firearm 
classifications are private letter rulings issued to a particular 
requestor with respect to a specific item. Saying that ATF 
classification letters do not have the force of law may mislead the 
requestor into believing that the statutes and regulations referenced 
therein, or possible administrative actions taken by ATF (e.g., one 
saying that the firearm cannot be returned because it would place the 
recipient in violation of law), are not required to be followed. The 
GCA and NFA, and their implementing regulations, clearly have the force 
and effect of law. Should a requestor ignore the classification letter 
and move forward to produce and sell or import items classified as 
firearms in violation of the GCA or NFA, the classification letter 
could be used to prove the willfulness of the violation in a criminal 
prosecution, administrative licensing or tax collection proceeding, or 
for seizure and forfeiture of unlawfully produced or possessed weapons.
    The Department also disagrees with the comment that codification of 
the classification letter process fails to abide by the memorandum of 
the Attorney General entitled ``Prohibition on Improper Guidance 
Documents'' (Nov. 16, 2017), not only because classification letters 
are not ``guidance documents,'' but also because that memorandum was 
rescinded by the Attorney General by memorandum dated July 1, 2021, 
consistent with the President's Executive Order entitled ``Revocation 
of Certain Executive Orders Concerning Federal Regulations'' issued on 
January 20, 2021.\134\
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    \134\ See Memorandum for the Heads of All Department Components, 
Re: Issuance and Use of Guidance Documents by the Department of 
Justice at 1 (July 1, 2021), available at https://www.justice.gov/opa/page/file/1408606/download (defining ``guidance document'' as 
``a statement of general applicability'' that does not include 
either ``adjudicatory or administrative actions'' or ``rulings''); 
E.O. 13992, 86 FR 7049 (Jan. 20, 2021); see also Processes and 
Procedures for Issuance and Use of Guidance Documents, 86 FR 37674 
(July 16, 2021) (revoking 28 CFR 50.26 and 50.27).
---------------------------------------------------------------------------

    The Department agrees with the comment that it may be burdensome 
for requestors to submit instructions, guides, and marketing materials 
with a classification request if those materials are not available at 
the time of submission. However, as explained in the rule, these items 
and materials are important for ATF to determine whether an unfinished, 
disassembled, or nonfunctional item or kit is a ``firearm'' subject to 
regulation under law. When sold or distributed with a partially 
complete, disassembled, or nonfunctional item or kit, they must be 
submitted. The final rule mitigates this burden by excluding from this 
requirement submission of such items and materials with firearm samples 
that are complete and assembled.
    The Department also agrees with the comment that the requestor of a 
voluntary classification of a specific component as a frame or receiver 
should be able to rely on that classification for other models and 
configurations the requestor manufactures. For this reason, the final 
rule makes clear that: (1) Determinations made by the Director 
identifying the specific component of a weapon as the ``frame or 
receiver'' as defined are applicable to variants thereof; and (2) an 
ATF classification of a specific component as the ``frame'' or 
``receiver'' is applicable to or authoritative with respect to any 
other sample, design, model, or configuration of the same weapon so 
that the requestor does not need to submit additional requests for 
future variants. In addition, defining the term ``frame or receiver'' 
in a more limited manner in the final rule will reduce or eliminate the 
need for industry members to voluntarily request a classification from 
ATF when deciding which particular component of a weapon is the frame 
or receiver, thereby reducing manufacturing costs.
5. Concerns With Recordkeeping Requirements
a. Acquisition and Disposition Records
Comments Received
    Several FFLs stated they would have problems with recordkeeping and 
inventory if there is more than one frame or receiver. They claimed 
that paperwork and tracking would be very burdensome because parts 
swapping and replacements would result in multiple inventory entries. 
Likewise, many industry members asserted that serialization of multiple 
frames or receiver parts would create recordkeeping ``havoc.'' One 
commenter offered a hypothetical: Assume that ATF determines that a 
receiver has three separate parts, each of which must be serialized, 
and assume all three parts are made by the same manufacturer. If 
receiver part A is made on March 1, receiver part B is made on 
September 5, and receiver part C is made on December 8, the commenter 
was unsure which date would be the date of manufacture if recorded in a 
single entry. Or, if the dates were recorded in separate entries, the 
commenter stated this would be alarming because there would be 
duplicate serial numbers recorded for one firearm. Finally, the 
commenter asked whether, when all three parts were finally assembled to 
make a full receiver, would that action require another record, and if 
so, what would be that date of manufacture.
    Additionally, FFLs asserted it would be impossible to comply with 
the marking requirements because there is no compatible software they 
can use for recordkeeping and inventory. A major manufacturer stated 
that its current electronic business suite, which is responsible for 
tracking all parts and product inventory and for generating the

[[Page 24711]]

A&D records, is inherently incompatible with multiple serial numbers 
per firearm (whether matching or non-matching). It further stated it 
was not aware of a viable solution available to adapt this system in a 
way that would allow for tracking of multiple serial numbers per 
serialized item. This sentiment was echoed by several companies that 
highlighted the logistical problems with trying to keep track of 
multiple serial numbers on numerous frames or receivers.
    Another major manufacturer stated it would take years to test and 
change its already highly customized software suite to comply with the 
rulemaking. Its systems, it said, are not equipped to (1) process or 
manufacture firearms with more than one serialized component; (2) 
serialize and track more than one component with the same serial 
number; (3) associate more than one serial number with a complete 
firearm the company otherwise acquires; (4) generate the required A&D 
records; or (5) ``update'' a serial number to reflect marking of a PMF. 
The company stated it could not comply with the proposed rule and 
explained how trying to comply would be costly and disruptive to its 
manufacturing lines. These types of cost estimates provided by various 
companies are described further below. See Section IV.B.13 of this 
preamble.
    Manufacturers also pointed out an inconsistency between the 
proposed change to Sec.  478.123(a), which would require manufacturers 
to record the serial number and other required information ``not later 
than the close of the next business day following the date of 
manufacture or other acquisition,'' and proposed Sec.  478.92(a)(1)(v), 
which would require manufacturers to ``identify a complete weapon . . . 
no later than seven days following the date of completion of the active 
manufacturing process, or prior to disposition, or whichever is 
sooner.'' They asked how they can record the serial number and other 
information on a manufactured firearm by close of the next business day 
if it is not required to be identified for seven days from completion 
of its manufacture.
    Other industry members raised concerns about recording and 
reconciling frames or receivers that could be ``manufactured or 
acquired'' prior to the time period in which the required markings must 
be applied. These types of firearms (e.g., a fully machined, 
unserialized frame or receiver) could be numerous, and it appeared to 
commenters that ATF expected manufacturers to list these firearms that 
have no identifying information with an ``NSN'' serial number. This, 
according to commenters, would create difficulties because the 
manufacturer would have to keep track of unserialized parts in the A&D 
records and, if any of those firearms were destroyed prior to 
serialization, the manufacturer would have no way to identify which 
frame or receiver corresponded to each recorded NSN entry in the 
manufacturer's records. Commenters worried that this would result in 
countless recordkeeping errors and that theft/loss reporting of 
unserialized parts would be exceedingly difficult if not impossible. 
One suggested that a clear statement be added in the final rule that 
frames or receivers need not be ``acquired'' by manufacturers prior to 
marking if the parts being used in the manufacturing process could 
address this concern. Similarly, commenters stated that ATF Ruling 
2012-1, which provides a manufacturer seven days following the date of 
completion of a firearm (or frame or receiver to be shipped or disposed 
of separately) to both mark and record the identifying information in 
its records, should be retained.
    Several manufacturers contended that the ``commercial record'' 
exception in proposed Sec.  478.123(a), which would exempt 
manufacturers from recording the manufacture or acquisition of a 
firearm no later than the close of the next business day so long as 
they held a commercial record with relevant information, is irrelevant 
and would never apply. They argued that a ``commercial record'' is a 
record of transaction between a transferor and transferee and that 
internal manufacturer records are not ``commercial records.'' 
Therefore, they argued, the exemption from the next day recording 
requirement and allowance of up to seven days would never apply. They 
made similar arguments that the ``commercial record'' exception would 
also not apply for repair or replacement requests, thus making it 
impossible to comply with the next day business rule. Accordingly, they 
requested that the current seven-day deadline be retained.
Department Response
    Because the Department agrees with commenters that the definition 
of ``firearm'' in 18 U.S.C. 921(a)(3)(B) is best read to mean a single 
part of a weapon as being the frame or receiver, the final rule adopts 
three subsets of the proposed definitions of ``frame or receiver''--
``frame'' for handguns and variants thereof; ``receiver'' for rifles, 
shotguns, and projectile weapons other than handguns and variants 
thereof; and ``frame'' or ``receiver'' for firearm muffler or silencer 
devices. The more limited definitions adopted in the final rule should 
address the costs and software problems that commenters raised.
    The Department also agrees with commenters who pointed out the 
inconsistency between the marking and recordkeeping requirements for 
manufacturers. The Department agrees that the time period should be the 
same and has clarified that markings be placed, and firearms be 
recorded, no later than the seventh day following the date of 
manufacture or other acquisition for non-NFA weapons and the frames or 
receivers of such weapons. Likewise, to be consistent with the 
recordkeeping and ATF Form 2 submission requirements, NFA weapons and 
parts defined as firearms must be marked and recorded, and Form 2 
submitted, no later than close of the next business day after 
manufacture. The Department also agrees that the commercial record 
provision is not applicable to most manufacturers and that providing 
the seven-day grace period to both mark and record makes the commercial 
record allowance for non-NFA weapons that are manufactured unnecessary. 
For these reasons, that provision has been amended in the final rule to 
apply only to NFA weapons that are otherwise acquired commercially.
b. Recordkeeping for ``Privately Made Firearms''
Comments Received
    One manufacturer stated that it did not understand how FFLs are to 
record PMFs that are marked in accordance with State laws (e.g., 
Connecticut), which have different requirements for assignment and 
structure of a serial number.
Department Response
    Under the final rule, the licensee marking the frame or receiver of 
a PMF must place the licensee's abbreviated license number (also known 
as the ``RDS Key'') as a prefix before the unique identification number 
originally placed by the maker of the PMF that will be adopted by the 
licensee. The adopted markings must otherwise meet the marking 
requirements. This requirement allows ATF to trace the firearm to a 
particular licensee. If a State has issued a unique number that must be 
placed on a firearm, then the licensee's abbreviated FFL number would 
be added as a prefix to that number if the licensee is going to accept 
that firearm into inventory. Again, nothing in this rule requires a 
licensee to accept a PMF into inventory or to

[[Page 24712]]

mark (non-NFA) PMFs on behalf of unlicensed persons.
c. Record Retention Burden
Comments Received
    Generally, commenters opposed the requirement that FFLs retain 
their records indefinitely until they discontinue their business, 
arguing that doing so would be burdensome and costly. Some pointed to 
the cost and burden on gunsmiths if many of them had to become 
licensees in order to mark PMFs. Those gunsmiths would then be subject 
to all the recordkeeping requirements imposed upon FFLs. Other 
commenters also expressed concern that having FFLs retain their records 
indefinitely would raise privacy concerns and subject FFLs to potential 
liability. FFLs, they argued, are subject to break-ins, both physical 
and cyber. Consequently, criminals could access ATF Form 4473s, use 
them to target unsuspecting firearms owners, and steal their firearms.
Department Response
    The Department disagrees that the record retention rule is 
unreasonably burdensome; raises additional privacy concerns; increases 
the probability of break-ins; or exacerbates the deleterious effects of 
break-ins that do occur. At present, licensees are required to maintain 
their records of acquisition and disposition for at least 20 years. The 
Attorney General in this rule is exercising his authority under 18 
U.S.C. 923(g)(1)(A) and (g)(2) to extend the 20-year retention period 
for licensees so that their records are not destroyed. The rule allows 
``closed out'' paper records that are more than 20 years old to be 
stored in a separate warehouse, which would be considered part of the 
business or collection premises for this purpose and would be subject 
to inspection in accordance with 18 U.S.C. 923(g)(1) and 27 CFR 478.23. 
Alternatively, those paper records may be turned in to ATF if the 
licensee voluntarily chooses to discontinue its business or licensed 
activity for which those records were maintained, pursuant to 18 U.S.C. 
923(g)(4) and 27 CFR 478.127, even if it subsequently obtains a new 
license.
    With regard to persons who may become engaged in the business as 
gunsmiths so they can mark firearms, such persons have always been 
required by law to be licensed and maintain records of firearms they 
take into inventory for gunsmithing work, including engraving 
firearms.\135\ This rule clarifies that licensed gunsmiths do not need 
to be re-licensed as manufacturers for the sole purpose of engraving or 
otherwise marking PMFs. Additionally, in response to comments, the 
final rule reduces costs by clarifying that licensees may have firearms 
engraved on-the-spot by any person under the direct supervision of the 
licensee (i.e., without the engraver taking the firearm into an 
inventory) provided the marking requirements are met.
---------------------------------------------------------------------------

    \135\ See ATF Rul. 2009-1 (``Any person who is engaged in the 
business of . . . engraving firearms . . . must be licensed as a 
dealer, which includes a gunsmith, under the Gun Control Act.'').
---------------------------------------------------------------------------

d. Record Retention Impact on Public Safety
Comments Received
    Some commenters argued that requiring FFLs to maintain their 
records indefinitely (instead of for the current 20-year period) serves 
no purpose. They asked ATF to produce evidence that there is a 
statistically significant number of instances where a crime involved a 
firearm purchased outside the 20-year window to justify the change; 
further, they doubted that Form 4473s from over 20 years ago would be 
helpful in solving crimes. Other commenters stated that sales records 
rarely help solve cases and claimed that tracing has been known not to 
work. Many challenged the usefulness in changing the retention of 
record requirement, stating that the average time-to-crime for 
recovered firearms is less than 10 years and that ATF and other 
entities have previously said that a firearm is untraceable after 5 
years. At least one commenter opined that the retention period should 
be shortened to seven years.
Department Response
    The Department disagrees with commenters who said that the record 
retention requirement serves no purpose. Firearms are generally durable 
weapons that last many decades, and their lethality and potential use 
in crime does not diminish over time. As explained in this rule, 
firearms have been traced to retailers who destroyed numerous records 
that were older than 20 years, but those traces could not successfully 
be completed. The National Tracing Center (``NTC'') conducted an 
analysis of all trace requests submitted between January 1, 2010, and 
December 31, 2021, that were closed under a particular code in the 
tracing system indicating the FFL specifically informed ATF that it did 
not have records for that firearm because the records were more than 20 
years old and had been destroyed. A total of approximately 16,324 
traces, or 1,360 on average per year, could not be completed during 
this time period because the records had been destroyed. Of these total 
unsuccessful traces, approximately 182 of the traces were designated as 
``Urgent,'' 1,013 were related to a homicide or attempted homicide (not 
including suicide), and 4,237 were related to ``Violent Crime.'' 
Further, with the advancement of electronic scanning and storage 
technology, maintaining old records is not as difficult or costly as it 
was when ATF first allowed records over 20 years old to be destroyed in 
its 1985 rulemaking. See 50 FR at 26702.
e. Alternatives to Record Retention Requirement
Comments Received
    One commenter, who believed the extended recordkeeping to be a 
burden, stated that ATF needs to be consistent in its use of language. 
The commenter cited the difference in phrasing between Sec.  
478.129(b)--``until business is discontinued''--and Sec.  478.129(e)--
``until business or licensed activity is discontinued.'' The commenter 
questioned the meaning of the latter phrase, asking if it refers to the 
actual closing down or the lapsing of a specific license. This could 
impact high volume dealers in their decision to either renew a current 
license or to allow it to lapse and apply for a new license, as a means 
of relieving the burdensome recordkeeping requirements. If ATF is 
purposefully using the different phrases, the commenter asked ATF to 
provide more clarity.
Department Response
    The Department agrees with the comment that discontinuance of 
business includes cessation of ``licensed activity'' or lapse of a 
specific license, and that the language of proposed Sec.  478.129(b) 
and proposed Sec.  478.129(d) should have included the same language as 
paragraph (e). The final regulatory text has been amended accordingly.
6. Clarity on Unlawful Conduct
Comments Received
    Commenters objecting to the proposed inclusion of ``weapon parts 
kits'' in the definition of ``firearm'' expressed concern about the 
expansion of conduct that would be considered unlawful. In the NPRM, 
ATF explained it was clarifying that weapon parts kits are included 
under the definition of a ``firearm'' so that FFLs who sell these kits 
to unlicensed individuals would be required to complete the ATF Form 
4473, background check, and recordkeeping requirements. 86 FR at

[[Page 24713]]

27726. ATF further explained in footnote 45 of the NPRM that persons 
engaged in the business of selling or distributing weapon parts kits 
cannot avoid licensing, marking, recordkeeping, or other requirements 
to which FFLs are subject ``by selling or shipping the parts in more 
than one box or shipment to the same person, or by conspiring with 
another person to do so.'' Id. at 27726 n.45.
    Commenters claimed that individuals, producers, and retailers will 
be left guessing what constitutes a weapon parts kit because, in the 
commenters' opinion, it was unclear from the proposed definition how 
many orders could constructively constitute a weapon parts kit over a 
period of time. They worried that a simple misstep, such as an 
individual selling components or tools that could be part of a weapon 
parts kit, could result in prison time if the individuals selling the 
components or tools could be viewed as having conspired with other 
dealers or manufacturers to sell a complete weapon parts kit.
Department Response
    In response to some commenters who expressed confusion concerning 
footnote 45 of the NPRM, 86 FR at 27726, as to what conduct is 
acceptable with respect to the sale or distribution of weapons parts 
kits or aggregations of firearm parts, the Department reiterates that 
title 18 of the U.S. Code includes Federal felony violations that can 
apply to circumstances involving the final rule's requirements. These 
include criminal prohibitions on: Engaging in the business of 
importing, manufacturing, or dealing in firearms without a license (18 
U.S.C. 922(a)(1)(A)); engaging in the business of importing or 
manufacturing ammunition without a license (18 U.S.C. 922(a)(1)(B)); 
aiding and abetting or causing such conduct to occur (18 U.S.C. 2); and 
conspiring with another to engage in such conduct (18 U.S.C. 371).\136\ 
Additionally, persons who manufacture and sell unassembled weapons or 
weapon parts kits in ``knockdown condition'' (i.e., unassembled but 
complete as to all component parts) cannot structure transactions to 
avoid paying Firearms Excise Tax on their sales price.\137\ In sum, 
persons cannot undermine these requirements and prohibitions by working 
with others or structuring transactions to avoid the appearance that 
they are not commercially manufacturing and distributing firearms.\138\
---------------------------------------------------------------------------

    \136\ Further, under 18 U.S.C. 1715, except for customary trade 
shipments between licensees, firearms capable of being concealed on 
the person, including handgun frames or combinations of parts from 
which handguns can be assembled, are prohibited from being mailed by 
the United States Postal Service. 39 CFR 211.2(a)(2), (a)(3); United 
States Postal Service, Publication 52--Hazardous, Restricted, and 
Perishable Mail at sec. 432.2(d) (Oct. 2021), available at https://pe.usps.com/text/pub52/pub52c4_009.htm (last visited Mar. 23, 2022).
    \137\ See 26 U.S.C. 4181 (imposing on the manufacturer, 
producer, or importer an excise tax of 10 percent (pistols and 
revolver) or 11 percent (other firearms) on the sale prices of 
firearms manufactured, produced, or imported, including complete, 
but unfinished, weapon parts kits); Rev. Rul. 62-169, 1962-2 C.B. 
245 (kits that contain all of the necessary component parts for the 
assembly of shotguns are complete firearms in knockdown condition 
even though, in assembling the shotguns the purchaser must ``final-
shape,'' sand, and finish the fore-arm and the stock); Internal 
Revenue Service Technical Advice Memorandum 8709002, 1986 WL 372494, 
at *4 (Nov. 13, 1986) (for purposes of imposing Firearms Excise Tax 
it is irrelevant whether the components of a revolver in an 
unassembled knockdown condition are sold separately to the same 
purchaser in various related transactions, rather than sold as a 
complete kit in a single transaction); cf. Rev. Rul. 61-189, 1961-2 
C.B. 185 (kits containing unassembled components and tools to 
complete artificial flies for fisherman were sporting goods subject 
to excise tax); Hine v. United States, 113 F. Supp. 340, 343 (Ct. 
Cl. 1953) (kits consisting of a fishing rod ``blank'' and everything 
necessary to complete a fishing rod were subject to excise tax 
having ``reached the stage of manufacture or development where they 
became recognizable as . . . rods . . . even though there remained 
one or more finishing operations to be performed''). The Alcohol and 
Tobacco Tax and Trade Bureau of the U.S. Department of the Treasury 
should be consulted with respect to the imposition of Firearms and 
Ammunition Excise Tax. See U.S. Dep't of the Treasury, Manufacturers 
and Producers (Apr. 17, 2018), available at https://www.ttb.gov/firearms/manufacturers (last visited Mar. 23, 2022).
    \138\ See, e.g., United States v. Evans, 928 F.2d 858, 859-62 
(9th Cir. 1991) (affirming convictions for conspiracy to cause, and 
aiding and abetting, the possession of unregistered machineguns 
where one defendant sold parts kits containing all component parts 
of Sten machineguns except receiver tubes and the other sold 
customers blank receiver tubes along with detailed instructions on 
how to complete them).
---------------------------------------------------------------------------

7. Stifles Technological Innovation
Comments Received
    Several commenters opposed the NPRM because they believed that it 
would discourage technological innovation and ignored the realities of 
the design and engineer process. Commenters stated that companies or 
new entrants to the market will generally manufacture in accordance 
with the ``safe-harbored'' products identified within the proposed 
definitions because they fear the risk of non-compliance and the 
resulting potential for liability.
Department Response
    The Department disagrees that the rule will stifle innovation. 
Because of this rule, licensees will have a better understanding of 
which portion of a weapon is the frame or receiver with respect to 
current and new designs and will be able to mark those firearms without 
seeking guidance from ATF. By providing much needed clarity as to what 
is a frame or receiver, ATF is encouraging innovation by providing a 
framework under which new ideas and technology can develop. With the 
advancement of split and modular firearm designs in which components 
may become separated, these updates are necessary to identify firearms 
for inventory control and to allow tracing. To alleviate the cost to 
add the associated licensee information on existing frames or 
receivers, the final rule requires only new designs (i.e., those that 
are functionally modified or altered) to be identified with the 
associated licensee's name, city and State, and serial number or, 
alternatively, the licensee's name and the serial number beginning with 
an abbreviated license number as a prefix to the unique identification 
number. Again, under this final rule, there would be only one frame or 
receiver of a given weapon.
8. Does Not Enhance Public Safety
Comments Received
    Thousands of commenters opposed the changes in the NPRM, arguing 
that the NPRM will not enhance public safety and that adding serial 
numbers will do nothing to reduce crime. Some commenters stated that 
ATF presented no evidence that definitively links firearm part 
serialization with statistically significant violent crime reduction 
and failed to show evidence that serialized firearms clearly assist in 
law enforcement investigations that result in the return of stolen or 
lost firearms.
    Commenters opposed to the rule claimed that PMFs or ``ghost guns'' 
are not generally used by criminals because they are too expensive to 
build and that firearms make their way into the hands of criminals 
through theft or other activity. In the experience of at least one 
commenter, 3D printing of firearms can be a time intensive process 
where a single print of a handgun can take anywhere from 48 to 72 hours 
to finish. Further, it can take several tries to get a print done, 
which can take a period of several days. This time investment, in the 
commenter's opinion, makes it less likely that criminals are using 3D 
printing to create firearms they intend to use in crimes.
    Further, commenters wrote that, even if ATF required markings on 
PMFs, it is well known that criminals simply obliterate serial numbers. 
Numerous

[[Page 24714]]

commenters also pointed to ATF's Motion to Dismiss in the California v. 
ATF lawsuit, where the State of California asked the Federal court to 
direct ATF to vacate its determinations that unfinished pistol frames 
and receivers are not subject to the same regulations as other firearms 
and to direct ATF to classify so-called ``80%'' frames and receivers as 
firearms subject to Federal firearms statutes and regulations. 
Paraphrasing ATF's arguments from the agency's Motion to Dismiss, 
commenters stated that ATF argued ``eight such crimes out of the 1.1 
million violent crimes committed in the relevant six-year-period is a 
far cry from an overwhelming wave that would cause a State injury 
sufficient to confer standing . . . . Nor can California plausibly 
plead that those crimes would not have occurred with traditional, 
serialized firearms.'' Likewise, commenters also took issue with the 
data ATF presented in the NPRM regarding the 23,906 PMFs submitted for 
tracing from 2016 through 2020. They stated that ATF needed to provide 
context for the data it presented. They claimed the data presented is 
not sufficient to demonstrate that PMFs are actually used in crimes and 
that ATF has been able to argue only that ``suspected'' PMFs were 
``reported'' to be present in ``potential'' crime scenes. Further, they 
opined that the PMFs recovered might actually involve hundreds of 
factory-made firearms with the serial numbers removed.
    Other commenters countered ATF's data by citing a Bureau of Justice 
Statistics' (``BJS'') publication to try to show that criminals do not 
use PMFs. See BJS, Source and Use of Firearms Involved in Crimes: 
Survey of Prison Inmates, 2016 (Jan. 9, 2019), available at https://bjs.ojp.gov/library/publications/source-and-use-firearms-involved-crimes-survey-prison-inmates-2016. In that survey, 287,400 surveyed 
prisoners had possessed a firearm during their offense. Among these, 
more than half (56 percent) had either stolen it (6 percent), found it 
at the scene of a crime (7 percent), or obtained it off the street or 
from the underground market (43 percent). Most of the remainder (25 
percent) had obtained it from a family member or friend as a gift. The 
report said only 7 percent of felons surveyed purchased their firearms 
legally through an FFL. In sum, commenters claimed that the NPRM is a 
solution in search of a problem and is not addressing an actual 
problem.
Department Response
    As discussed in the Section II.A of this preamble, the submission 
of PMFs reported for tracing by law enforcement is increasing at an 
exponential rate, especially over the last three years, which is more 
recent than the 2016 BJS data relied on by commenters. Further, unlike 
commercially produced firearms, it is difficult for licensees to 
account for PMFs in their inventories and to report thefts or losses of 
those weapons to law enforcement and insurance companies. The current 
technology for privately making firearms, including 3D printing, is 
continually improving, and the Department and ATF have the authority 
and obligation to promulgate regulations to implement the GCA in light 
of the public safety goals of that statute.
    The Department disagrees that PMFs can statistically be compared to 
firearms that have undergone background checks, or with firearms 
recovered that have been marked with serial numbers and other 
identifying information. As explained in this rule, PMFs are being 
assembled from parts without background checks. They are not yet being 
acquired through the primary market in quantities like commercially 
produced firearms. But they are easily acquired by persons prohibited 
by law from receiving or possessing firearms, and they therefore pose a 
significant threat to public safety. Moreover, unlike other firearms 
recovered by law enforcement, PMFs are far more difficult for law 
enforcement to trace when recovered at a crime scene because they lack 
serial numbers and other identifying markings. With the advancement of 
firearms technology, PMFs will, over time, eventually make their way 
into the primary market as they become more reliable, and where they 
can be marketed broadly, pawned, or repaired.
9. Tracing Efforts Hindered
Comments Received
    Commenters asserted that the NPRM will not enhance public safety 
because the new requirements will only make it more confusing for law 
enforcement officers when tracing firearms. Commenters stated that 
criminals could simply acquire two copies of the same model and 
interchange or swap parts, which would send law enforcement on a wild 
goose chase. Other commenters stated that individuals typically swap 
out upper and lower assemblies to alternate calibers or to use 
different barrels, which would lead to more than one serial number on 
the firearm. In these cases, an officer may find two or three different 
serial numbers and submit all the numbers to ATF for tracing, which 
would require ATF to contact multiple manufacturers, distributors, and 
retailers, and possibly multiple transferees who purchased firearms.
Department Response
    The Department agrees with commenters who said that, under the 
proposed rule, law enforcement may find it more difficult to trace 
firearms with more than one serial number. For this reason, the final 
rule accepts commenters' suggestions asserting that the term ``frame or 
receiver'' should be defined to mean only a single housing with one 
unique serial number that is not duplicated on any other firearm. The 
Department agrees with commenters that doing so will be less costly for 
licensees to mark and record, and for law enforcement to trace firearms 
involved in crime. Therefore, the Department has defined the term 
``frame or receiver'' to focus on only one part that is marked on a 
particular weapon or firearm muffler or silencer. In the case of a 
multi-piece frame or receiver, however, the final rule makes clear 
that, if there are two or more similar subparts that make up a multi-
piece frame or receiver, then those subparts would be marked with the 
same serial number and associated licensee information. Thus, there 
should be very few circumstances in which there are more than one 
unique serial numbers placed on a weapon (e.g., a remanufactured or 
imported firearm where the manufacturer or importer chooses to mark its 
own serial number rather than adopting an existing serial number).
10. Punishes Law-Abiding Citizens
Comments Received
    Numerous commenters objected to the NPRM because they believed it 
could turn law-abiding citizens into felons and would only serve to 
punish hobbyists who build their own firearms. Concerned that firearms 
in their possession would have more than one frame or receiver and 
therefore would need more than one part marked, commenters opposed to 
the rule expressed concern that they would be automatic felons once the 
regulation becomes effective. For instance, commenters stated that, if 
the upper for an AR-15 is considered a receiver under the rule, then 
thousands of law-abiding citizens who own these items would become 
felons overnight. Other commenters similarly questioned whether they 
will have violated the NFA or GCA if they sell or purchase an unmarked 
partially completed weapon parts kit after the final rule is enacted.

[[Page 24715]]

Department Response
    The Department disagrees that this rule turns law-abiding citizens 
into felons and only serves to punish hobbyists who build their own 
firearms. Nothing in this rule prevents unlicensed law-abiding citizens 
and hobbyists from making their own firearms by using commercially 
produced parts or by using 3D printers; or from transferring PMFs to 
others as long as they are not engaged in a business or activity 
requiring a license. If such persons wish to engage in the business of 
manufacturing, importing, or dealing in firearms, they must obtain a 
license like any other manufacturer, importer, or dealer. Of course, 
private makers must abide by the Undetectable Firearms Act, 18 U.S.C. 
922(p); NFA requirements; and any applicable State and local laws that 
govern privately made firearms. With regard to commenters' assertion 
that there would be more than one ``frame or receiver'' on a given 
weapon, this final rule does not define that term in a manner that 
would result in more than one on a particular weapon.
11. Impacts on Underserved and Minority Communities
Comments Received
    Numerous commenters asserted that the NPRM is racist and would 
negatively impact the poor and minority communities. They requested 
that the rule either be rescinded or that a ``racial equity analysis'' 
be conducted to prevent any racially discriminatory outcomes. These 
types of commenters stated, for example, that the requirements for 
serial numbers will disproportionately impact the poor, elderly, and 
minorities and will place the nation's citizens at increased risk from 
criminals. Other commenters stated their belief that the rule will 
result in more Black Americans being arrested, prosecuted, and 
incarcerated and thus will harm already vulnerable communities. Another 
commenter contended the proposed rule is at odds with the President's 
equity initiatives in that, although the Administration is considering 
equity in pursuing policy changes to education, employment, and 
housing, this policy of promoting equity should also include ``firearms 
equity.'' The commenter indicated that increased costs to gun 
manufacturers under this proposal would not only affect small 
businesses but also would have a disparate impact on low-income 
citizens, who are disproportionately persons of color, according to the 
commenter. Accordingly, the commenter stated that ATF must provide data 
and a comprehensive analysis to prove that the NPRM does not unfairly 
and inequitably penalize any racial or ethnic group, nor harm any 
protected civil rights class. Further, the commenter argued that ATF 
should seek to increase gun affordability for low-income citizens and 
increase gun ownership among disadvantaged people.
Department Response
    The Department disagrees that additional racial equity analysis 
needs to be conducted on the rule or that this rule is inconsistent 
with equity initiatives of the Administration. This final rule 
implements the GCA, which regulates commerce in firearms. The GCA, in 
part, requires that all firearms manufactured, imported, and sold by 
FFLs, or transferred through FFLs, be marked with serial numbers in 
order to be traceable wherever those firearms are recovered by law 
enforcement nationally or internationally. A firearms trace provides an 
investigative lead to law enforcement regarding the identity of the 
unlicensed person who first purchased the firearm from a firearms 
retailer (or at retail from a manufacturer, importer, or wholesaler); 
the identification of that person does not automatically indicate that 
the person is a criminal. The GCA does not distinguish between 
communities in the United States; further, ATF is prohibited under 
Federal law from maintaining a registry of firearms or firearms owners, 
see 18 U.S.C. 926, with the exception of weapons subject to the NFA, 
and therefore ATF does not know who owns firearms, nor does it keep 
track of who builds their own PMFs. Accordingly, there is no way for 
ATF to anticipate or measure now or in the future how the rule would 
impact particular communities based on racial or socio-economic 
distinctions. Lastly, it is not within the scope of the GCA, or the 
Department's or ATF's purview, to increase gun affordability for low-
income citizens and increase gun ownership among any particular group 
of people. For additional information, see Section IV.A.5.h of this 
preamble.
12. Other Priorities and Efficiencies
Comments Received
    Many commenters stated that the Department and ATF should not 
attack law-abiding citizens but should instead focus on real criminals 
and enforce the existing firearms laws. They stated that ATF should 
expand resources in the investigation and assistance of prosecution of 
weapons charges and more fully advise the courts on such technical 
issues. Other commenters stated that the government should devote 
resources to solving mental health issues or combating drugs on the 
street. Other commenters suggested that the government propose new 
sentencing guidelines for individuals who steal or utilize firearms in 
criminal activities rather than enact new rules that impact only law-
abiding citizens.
Department Response
    The Department agrees with commenters that mental health and drugs 
are important issues for the government to address, but disagrees that 
this rule improperly diverts ATF resources. To the contrary, the rule 
is absolutely necessary to allow ATF to focus its resources. The rule 
accomplishes this goal by helping to ensure that firearms recovered 
from crimes can be traced through licensee records using the 
information marked on the frame or receiver of each firearm. Not only 
do more traceable firearms lead to increased discovery and prosecutions 
of criminals, but they also provide ATF with key crime gun 
intelligence, such as firearm trafficking patterns through multiple 
sales reports, demand letters of licensees with a short ``time-to-
crime,'' and theft/loss reports.\139\
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    \139\ See footnotes 33 and 39, supra.
---------------------------------------------------------------------------

13. Concerns With the Economic Analysis
a. Addressing an Externality
Comments Received
    In the NPRM, ATF stated that this rule would address externalities. 
86 FR at 27738. Commenters stated that externalities result from 
inefficiencies in market transactions. Commenters stated that ATF 
failed to address how criminals produce a negative externality by using 
an unmarked weapon when committing a crime. In addition, commenters 
stated that commercial activity should not be held responsible for any 
difficulties ATF experiences in enforcing Federal law.
Department Response
    ATF concurs that this rule would not address externalities due to 
market inefficiencies; therefore, to avoid any confusion, the language 
in the NPRM that suggested that this rule would address a market 
inefficiency has been removed in the final rule. Regardless of this 
change, publication of this rule remains necessary to enforce the GCA 
and NFA.

[[Page 24716]]

b. Overall Costs
Comments Received
    Many commenters stated that the costs that ATF attributed to the 
rule did not account for the full number of PMFs currently in 
circulation. They stated that there are as many as 20 million 
individuals or PMFs that would be affected by this rule. In addition, 
one commenter suggested that the overall cost estimate in the NPRM 
(which the commenter calculated to be seven cents per firearm for all 
firearms currently in circulation) was not a realistic cost estimate 
given the comprehensive changes being made to the industry as a whole. 
One commenter suggested that a low estimate of $45 to mark each firearm 
should make the overall cost estimate over $100 million. Another 
commenter believed that the increased cost to the consumer of five 
dollars per firearm is too low because this cost includes engraving, 
paperwork retention, legal services, and engineering, all of which 
would be necessary to achieve compliance with the new regulations. 
Several commenters stated that the 20-year estimate of $1.1 million is 
too low. One commenter stated that, if an ``80%'' receiver or frame 
sells for $100, the $1.1 million estimate would mean that only 550 
receivers or frames were sold per year--a number the commenter believed 
was ``impossibly low.'' Commenters asserted that companies would suffer 
substantial losses or go out of business altogether. One commenter 
asked if businesses would be compensated if their actual costs were 
above the costs estimated in the rule.
    Some commenters suggested that requiring multiple serial numbers 
would also be cost prohibitive for manufacturers and make the rule 
economically significant. A commenter suggested that the manufacturing 
costs alone would be at least $400 million. Many commenters stated that 
ATF failed to compile data on unfinished receivers and kit sales and 
that ATF does not know how commerce would be affected by the rule 
change. One commenter stated that, to comply with new regulations, 
companies would need to seek legal advice and train employees on the 
regulations and form changes, which would exceed the cost estimate of 
$10 per company.
    One commenter wanted to know if ATF had considered how higher 
demand for determinations would affect the agency and the manufacturers 
awaiting these determinations. Additionally, this commenter wanted to 
know if ATF had considered the costs to Federal, State, and local 
agencies to train law enforcement to recognize items now classified as 
firearms and the increased workload on ATF to regulate firearms with 
multiple frames or receivers.
    One commenter stated that some individuals must drive long 
distances to reach an FFL. These trips are expensive and time 
consuming. Another commenter stated that the cost estimate for 
individuals was too low because it failed to consider the time and 
transportation costs of travel to an FFL to transfer parts, such as 
upper receivers or pistol slides, which the commenter believed would be 
required to be serialized under the rule.
Department Response
    ATF agrees that the costs of the rule did not account for PMFs 
currently owned by law-abiding individuals, but this is because the 
rule does not affect individuals in possession of PMFs unless the 
individual tries to sell or otherwise dispose of the PMF though an FFL. 
ATF cannot agree with the commenter that there may be up to 20 million 
PMFs in private circulation because ATF does not maintain any data that 
would allow for an estimate of the number of PMFs. In any event, PMFs, 
by definition, are not serialized by FFLs and would only need to be 
serialized if the individual with the PMF transfers it to an FFL. 
Nonetheless, ATF significantly revised its economic analysis in 
preparing the final rule to better reflect the rule's impact on these 
affected populations.
    Where feasible, the Department has reduced some of the burdens on 
the regulated community. Rather than requiring multiple serial numbers, 
the final rule amends the proposed definition of ``frame or receiver'' 
to identify one part of a firearm to be the ``frame'' or ``receiver'' 
that requires a serial number (with the exception of multi-piece frames 
or receivers that are composed of multiple modular subparts, which 
require placement of the same serial number and associated licensee 
information on those parts). Because there will almost always be one 
serial number per firearm under the final rule, no Federal, State, or 
local costs were considered for law enforcement to review firearms with 
multiple serial numbers.
    ATF concurs with the comment that entities will need to provide 
training to employees to ensure compliance when any new regulations are 
published. However, ATF disagrees that these costs should be considered 
under the rule. Activities such as training employees and obtaining 
legal opinions in response to a new regulation of this type are usual 
activities for complying with the regulatory requirements in this 
industry and are not treated as new costs associated with the rule. 
Where manufacturers have been granted determination letters for their 
firearm designs, these designs have been grandfathered to be excluded 
from the final rule, except for those determinations that a frame or 
receiver had not reached a stage of manufacture to be classified as a 
frame or receiver. Due to these changes and the revised definitions 
under the final rule, ATF does not anticipate that manufacturers and 
retailers of currently regulated firearms will incur significant costs 
from the publication of this final rule.
c. Affected Populations
Comments Received
    One commenter suggested that ATF underestimated the overall number 
of the affected populations because the number of public comments 
received on the proposed rule was more than the number of affected 
entities listed in the NPRM. One commenter stated that the total 
affected population should include all businesses that sell firearms 
components, not just makers of unfinished frames or receivers. One 
commenter stated that ATF failed to include ``micro-scale'' businesses 
that specialize in firearms customization for marksmanship 
competitions, and that many small businesses that sell semiautomatic 
pistol slides and accessories, which they believed would be 
reclassified as firearms by the final rule, would need to become 
licensed as dealers or manufacturers.
    Many commenters stated that the Regulatory Impact Analysis 
(``RIA'') did not account for the costs incurred by individuals. Many 
commenters estimated a total number of PMFs already in circulation and 
estimated that the cost for those currently in circulation would be 
millions of dollars. Some commenters stated that the NPRM should have 
included an estimate of the number of PMFs and unfinished receivers 
that would be reclassified as firearms. Multiple commenters stated that 
there were millions of firearms produced prior to 1968 that are not 
serialized and that requiring application of a serial number to these 
firearms would lower their value.
    Commenters estimated that approximately 300 million firearms would 
need to be serialized under the rule and that the time frame to 
serialize these firearms under the proposed rule would be unreasonably 
short. Other commenters estimated approximately 3 million PMFs would 
need to be marked

[[Page 24717]]

under the rule. For these PMFs, they estimated the costs for associated 
marking and transfer fees to be $180 million dollars.
Department Response
    ATF disagrees that the number of entities affected by the rule is 
the same or similar to the number of individuals who have commented on 
the proposed rule. The Small Business Administration considers small 
entities to be businesses, non-governmental organizations, or small 
governmental jurisdictions--not individuals. The estimated number of 
entities affected by the rule will be significantly smaller than the 
number of individuals who commented on the rule or who currently 
possess PMFs. Under the final rule, PMFs owned by individuals do not 
have to be serialized unless the PMF is transferred to an FFL and the 
FFL voluntarily accepts the PMF into inventory. At the time of the 
NPRM, ATF assumed that individuals who own PMFs would likely choose to 
avoid going through an FFL when disposing of their firearms to avoid 
serializing their PMFs. However, for the final rule, ATF outlines the 
individual populations and costs if individuals choose to take their 
PMFs to an FFL, and if that PMF is accepted into inventory. In 
addition, neither the NPRM nor this final rule define ``privately made 
firearm'' as including firearms manufactured or made prior to October 
22, 1968, and this rule does not affect pre-October 22, 1968, firearms 
that were not serialized unless remanufactured after that date.
    ATF did not account for the costs to entities that specialize in 
firearms customization for marksmanship competitions because the 
changes to the final rule's definition of ``frame or receiver'' would 
not change the ability of these ``micro-sale businesses'' to customize 
firearms by replacing pistols slides and accessories. Under the final 
rule, these items would not be considered ``frames or receivers.'' 
Therefore, those businesses would not be required to be licensed as 
manufacturers if they customize firearms by replacing pistol slides and 
accessories for individual unlicensed customers.
d. Definition of ``Frame or Receiver''
Comments Received
    Many commenters stated that having firearms with multiple serial 
numbers would be cost prohibitive. Some commenters suggested that, 
should manufacturers have to mark multiple serial numbers, retooling 
designs would cost a significant amount of money and investment. They 
also asserted manufactures would have to spend time and money to match 
up the firearm pieces into one firearm. Some commenters suggested that 
this would increase the cost of firearms for purchasers. Other 
commenters stated that the industry would need to change how it marks, 
sells, and advertises unfinished receivers that would be considered 
``firearms'' under the final rule.
    Commenters stated that the new regulations requiring multiple parts 
to be serialized would harm both citizens and the firearms industry by 
limiting growth and innovation in the industry. One commenter stated 
that the industry would be forced to seek determinations from ATF 
because manufacturers would be unable to determine which part of the 
firearm is the frame or receiver. Other commenters stated that firearms 
manufacturers would be forced to mark multiple parts of a firearm 
because they might not have requested a determination or received a 
response to a determination request submitted to ATF. One commenter 
stated that restricting the parts of a firearm that a company can sell 
would cause a shift in supply and demand.
    One commenter asserted that the cost estimates did not align with 
how the manufacturing process works. The commenter claimed that, to 
comply with the rule, manufacturers would have to totally rework their 
manufacturing processes and recordkeeping systems. Another commenter 
stated that companies that produce raw forgings and castings would be 
required to become FFLs. The commenter claimed that this would increase 
the cost of these items or cause manufacturers to change their 
production to include machining of the raw materials.
    Some commenters suggested that it would cost more to purchase 
individual pieces because they would now have to go through FFLs to 
purchase their firearm kits and pay a transfer fee for each frame or 
receiver they purchase. One commenter asked if there would be enough 
FFLs to serialize firearms in the required time period, asked how 
individuals with disabilities or without transportation would visit an 
FFL to have their firearms serialized, and asked if individuals would 
be reimbursed for unserialized firearms seized by the government.
Department Response
    Based on the public comments received, the final rule changes the 
proposed definition of firearm ``frame or receiver'' to identify only 
one part of a firearm that will need to be marked. However, if a 
company were to sell a firearm parts kit with a partially complete 
``frame or receiver,'' or a multi-piece frame or receiver where there 
is more than one modular subpart, the frames or receivers of these 
items will now need to be serialized in accordance with this rule, 
increasing the cost of these items.
    ATF acknowledges that the proposed regulation would have posed some 
compliance issues for manufacturers and that some companies that were 
not FFLs would have needed to become FFLs under the proposed rule. ATF 
modified the rule to alleviate those concerns by expressly excluding 
raw materials, by further clarifying certain terms, and by allowing 
manufacturers to adopt existing marks of identification in several 
circumstances. Further, retailers were required under the NPRM--and are 
required under the final rule--to mark only unserialized firearms that 
they currently have in inventory and any PMFs they take into inventory 
after the implementation of the final rule. In this regard, licensees 
will continue to have 60 days until after the effective date of the 
final rule to serialize firearm parts kits with partially complete 
``frames or receivers'' that they currently have in inventory.
    ATF concurs that individuals will now need to visit an FFL to 
purchase those firearm parts kits with a partially complete ``frame or 
receiver'' that may readily be completed, like other firearms. However, 
because there will only be one frame or receiver per kit, there will be 
no additional transfer fees.
e. Firearm Kits With ``Partially Complete Frames or Receivers''
Comments Received
    ATF received various comments regarding the methodology used for 
determining populations and costs for non-FFL manufacturers of 
partially complete frames or receivers and firearm kits. Several 
commenters treated the manufacturers and retailers of these items as 
one group and stated that the population estimated by ATF was too low. 
One commenter claimed that ATF misstated the number (36) of non-FFLs 
selling firearm parts kits with a partially complete ``frame or 
receiver'' because an internet search the commenter conducted on ``80 
lower'' returned more than 75 websites selling these items.
    Many commenters asserted that ATF could not properly determine how 
much of an effect on commerce this rule will have for manufacturers. 
Some commenters stated that ATF did not account for non-FFL 
manufacturers

[[Page 24718]]

becoming licensed. Other commenters claimed that the new regulations 
would ruin non-FFL businesses that sell unregulated parts. One 
commenter opined that non-FFL manufacturers are not likely to become 
licensed and that, because most of these companies are small, this 
final rule will force these companies to go out of business. One 
commenter stated that ATF did not account for lost revenue and 
increased expenses for gunsmiths, companies producing firearm parts 
kits, and individuals. Some public commenters stated that non-FFLs 
would be unable to become licensed either due to the costs associated 
with becoming licensed or zoning restrictions, and that ATF did not 
account for companies going out of business.
    Commenters stated that ATF did not estimate the impact on revenue 
this rule will have on the public and that ATF's assumptions were 
unsupported. One commenter stated that ATF made a flawed assumption 
that there would be no cost because non-FFL manufacturers would choose 
not to become licensed because of the ``primary marketing scheme of 
some of these non-FFL manufacturers.'' The commenter claimed that, even 
if only a few of these manufacturers choose to become licensed, the 
costs could be in the millions. Another commenter similarly stated that 
there was no analysis or evidence presented on non-FFLs choosing to 
become licensed or forgoing selling newly regulated items. One 
commenter stated that ATF failed to estimate the number of parts kits 
and PMFs and that it did not quantify the total costs for destroying or 
turning in such items. Additionally, the commenter stated that ATF 
failed to explain how it arrived at the conclusion that all non-FFL 
retailers would choose to destroy their inventory of unmarked parts 
kits and PMFs.
    One commenter stated that, according to the RIA, parts kits and 
some unfinished receivers currently available will no longer be sold. 
This commenter asked if the RIA assumed that non-licensed manufacturers 
will produce kits with ``unformed blocks of metal.'' The commenter 
believed that sales of such kits would be lower than sales of existing 
kits because it would take more skill and additional tools to transform 
the new kits into frames or receivers. One commenter stated that ATF 
failed to provide an analysis of the exact amount of revenue per 
business that non-FFL retailers would lose if they chose to sell part 
kits without unfinished receivers. One commenter stated that the 
assumption in the RIA was that kits without a frame or receiver would 
not be regulated, but that the text of the proposed rule did not make 
this clear.
    A couple of commenters stated that ATF's assumptions that 10 
percent of Type 01 and Type 02 FFLs currently deal in firearm parts 
kits with a partially complete ``frame or receiver'' and that all 
dealers would have only two such items in inventory lacked any 
supporting evidence or data and cited only unknown subject matter 
experts.
    Several commenters suggested that the populations, cost 
assumptions, and descriptions for in-house engraving were inaccurate. 
One commenter stated that engraving equipment is not common at FFLs. 
One commenter suggested that the only viable means of engraving is with 
a laser engraver, associated equipment and safety supplies, and a 
specialized worker. Several commenters suggested the labor and 
equipment needed to engrave existing inventory is significantly higher 
than the stamping method discussed in the NPRM. Another commenter 
stated that the costs in the ATF's analysis were underestimated and 
questioned how ATF came to the conclusions about the number of FFLs 
that have parts kits, who would mark the kits, how they would be 
marked, and why kits that do not need to be serialized would have an 
embedded metal plate on which to mark a serial number. The commenter 
also noted that ATF did not include the cost estimate for the 36 non-
FFL dealers to have their parts kits marked by a licensee. One 
commenter stated that ATF's estimate of a one-time cost for contracting 
out gunsmithing services in order to mark inventory that would need to 
be serialized was unsupported by evidence or data.
Department Response
    ATF partially concurs that the population of affected dealers of 
firearm parts kits with partially complete frames or receivers was 
underestimated. In the NPRM, ATF found 71 companies selling such kits. 
Because the requirements for manufacturers and retailers are different, 
ATF accounts for them separately in different chapters of the RIA, 
which makes the numbers per chapter lower than the population estimates 
suggested by commenters. Although all 71 companies sell firearm parts 
kits with a partially complete frame or receiver, ATF broke up the 
number of companies between manufacturers and dealers of kits. After 
receiving comments, ATF performed a second internet search of companies 
and found an additional 58 companies, but broke up the total number of 
companies into four groups: FFL and non-FFL manufacturers, and FFL and 
non-FFL dealers. By categorizing the companies this way, the population 
numbers appear to be relatively low in each chapter of the RIA, but the 
overall number of companies affected is similar to the estimated total 
number of companies suggested by the commenter.
    For the final RIA, ATF revised the methodology and costs associated 
with this final rule to incorporate the costs that commenters suggested 
will arise. ATF concurs that lost revenue was not accounted for in the 
proposed rule, and the final rule now incorporates both the loss in 
revenue for companies and additional expenses for individuals. Under 
the final rule, firearm parts kits with partially complete frames or 
receivers will no longer be able to be sold without a serial number. 
The RIA revised the estimates to assume that firearm parts kits with 
partially complete frames or receivers will be regulated. As a result, 
ATF revised its estimates to reflect companies that could dissolve 
their businesses and provided a more precise estimate as to how much 
revenue non-FFL retailers would lose due to the requirements of the 
final rule.
    In response to commenters that stated ATF's assumptions were 
lacking a detailed methodology or were otherwise unsupported, ATF 
reiterates that the agency does not maintain consolidated or aggregated 
records on companies' inventory, regardless of whether the item in 
question is regulated, nor can ATF interview all manufacturers to 
determine their intended future actions upon publication of the final 
rule. Moreover, most of the items in companies' inventories are not 
currently regulated. ATF has made reasonable estimates based on 
information provided by commenters, willing participants in 
informational surveys, and ATF subject matter experts. In the NPRM, ATF 
relied on subject matter experts from the Firearms Industry Programs 
Branch to provide an estimated population, i.e., the number of firearm 
parts kits with a partially complete frame or receiver in inventory. 
However, because such parts kits are not viewed by industry members as 
regulated, and because ATF does not have the inventory data that FFLs 
maintain, ATF is unable to obtain estimates at the level of accuracy 
requested by public commenters. However, to improve on these estimates 
for the final rule, ATF relied on general observations from its field 
divisions to estimate population and inventory. This was determined to 
be the best information available for the analysis.

[[Page 24719]]

    Next, ATF concurs with commenters that the costs associated with 
the in-house engraving methods outlined in the NPRM were inaccurate, 
and ATF has changed its assumptions that considered only FFLs that 
currently have gunsmiths on staff. ATF estimates a one-time contracting 
cost for gunsmithing services to account for FFLs that have firearm 
parts kits with a partially complete frame or receiver currently in 
inventory but do not have gunsmithing capabilities. ATF made this 
assumption because, based on anecdotal commentary from various ATF 
field division offices, as well as comments on the NPRM, most FFLs do 
not have gunsmiths on staff; therefore, it is unlikely that they will 
purchase engraving equipment if the staff and equipment are not already 
part of their normal operations. It is not clear that only FFLs with 
gunsmithing capabilities will carry firearm parts kits with a partially 
complete frame or receiver; therefore, ATF assumed that a portion of 
the population will need to contract for gunsmithing services.
    As for purchasing a laser engraver, associated equipment and safety 
supplies, and labor, ATF used information about such costs to 
illustrate engraving expenses for manufacturers. ATF disagrees that a 
licensed dealer will need to purchase such equipment or hire more 
employees with the requisite engraving skills because future firearm 
parts kits with a partially complete frame or receiver will be 
serialized by a licensed manufacturer and not the licensed dealer. ATF 
concurs that it did not account for costs from serializing such parts 
kits made from polymer materials. In order to account for these costs, 
ATF has now included the costs for disposing of such items if they 
cannot be serialized. ATF also concurs that the cost for non-FFL 
dealers to serialize was omitted from the analysis and therefore has 
incorporated such costs into its revised RIA.
f. Gunsmithing
Comments Received
    ATF received numerous comments on gunsmiths. Commenters, including 
a licensed manufacturer that operates as a small business, stated the 
rule will have a major impact on the business by increasing the cost of 
gunsmithing services and recordkeeping requirements. The licensee 
claimed that the resulting decrease in profitability will affect the 
company's ability to expand and asserted that the new regulations would 
complicate the process of performing a quick activity, such as bore 
sighting or adjustments, because the firearm must be recorded in the 
A&D records and the firearm must be marked with a serial number. This 
licensee also stated that many gunsmiths perform services that do not 
involve engraving and that these FFLs would need to expand their 
services or lose business.
    One commenter stated that persons should not have to be licensed to 
provide marking on firearms for nonlicensees because it is the 
responsibility of the FFL to ensure the firearm has been marked per 
regulation. The commenter also argued that licensing would increase 
costs without adding any benefits. Additionally, this commenter 
believed that ATF used the incorrect occupational code for salary and 
wages in the RIA and that the more precise code has a higher labor 
rate. One commenter described the significant burden and expense a 
gunsmith in training would endure to acquire the parts necessary to 
build 30 different firearms. The commenter explained that parts 
purchased online would need to be transferred through an FFL, which 
involves fees for completion of the Form 4473, and a second trip to the 
FFL after the required 10-day waiting period in his location.
    One commenter asked for an explanation regarding the ``one-time 
cost for contract gunsmithing estimated to be $180,849'' and the 
$45,212 listed in chapter 4.3 of the RIA. This commenter asserted that 
ATF underestimated the number of A&D Record entries that gunsmiths 
would need to make and the cost of making these entries. The commenter 
argued that the hourly wage used for the calculation is out of date 
because the cost of labor has increased. One commenter suggested there 
was a discrepancy regarding contract gunsmithing. Another commenter 
worried that ATF significantly underestimated the activities for 
gunsmithing and did not understand why the number of items needing to 
be serialized was so low. One commenter did not agree with ATF's 
assessment in chapter 4 of the RIA that ``3,359 FFLs would outsource 
their firearms to another FFL for gunsmithing work.''
Department Response
    ATF affirms that the current A&D Record requirements need to be 
maintained whenever firearms are acquired in inventory. The final rule 
clarifies that Type 01 and Type 02 FFLs that do gunsmithing work that 
includes marking services for nonlicensees are not required to apply 
for a Type 07 manufacturer's license. ATF reiterates that PMFs for 
personal use are not required by the GCA or this rule to be serialized 
(unless required by State or local law); instead, serialization is 
required only for those that are taken into inventory, which--as the 
final rule clarifies, based on ATF's longstanding view--does not 
include same-day adjustments or repairs. Because repairs are performed 
by gunsmiths, ATF assumes that only FFLs that are gunsmiths or hire 
gunsmiths will be performing repairs or customizations of PMFs, so ATF 
incorporated the annual costs for these FFLs.
    As stated by various public commenters and reinforced by ATF 
subject matter experts, not all FFL dealers are capable of engraving; 
therefore, there may be FFLs that outsource their existing inventory of 
firearm parts kits with a partially complete frame or receiver to 
another FFL or a non-FFL that has engraving services available under 
the FFL's direct supervision. Existing PMFs currently in inventory are 
not required to be marked under the FFL's direct supervision so long as 
the marking occurs within 60 days from the effective date of the rule, 
or prior to final disposition, whichever is sooner. As for the affected 
populations, because such parts kits are not currently viewed by their 
manufacturers or members of the public as regulated, ATF is not able to 
definitively determine the number of affected items that would need to 
be serialized with the specificity that commenters requested.
g. Silencers
Comments Received
    One commenter stated that ATF underestimated the cost to serialize 
all parts of a silencer while another commenter stated that the 
benefits of adding additional serialized parts of a silencer do not 
outweigh the costs. One commenter asked if ATF would pay for 
replacement of parts. One commenter believed that multiple parts of a 
silencer would be classified as the frame or receiver; the commenter 
also claimed that every silencer manufacture would need to request a 
variance and that ATF did not include the cost of processing the 
variances. One commenter asked if ATF would be covering the cost of a 
silencer part if it is damaged while the serial number is being marked. 
Additionally, the commenter wanted to know who would pay to have the 
silencer parts marked if all parts need to be marked.
Department Response
    In both the proposed and final rule, ATF required or requires only 
that the

[[Page 24720]]

``frame'' or ``receiver'' of a firearm muffler or silencer device be 
marked, and the final rule makes clear which part is the frame or 
receiver of a modular silencer. Additionally, the final rule makes 
clear that the end cap of a silencer or a sound suppressor cannot be a 
``frame'' or ``receiver.'' Based on public comments received in the 
ANPRM for silencers and mufflers, see 81 FR at 26764, the final rule 
will not significantly change the way the industry currently marks 
silencers. In most cases, the ``frame'' or ``receiver'' would be the 
outer tube.
    Under Federal law, 26 U.S.C. 5842(a), and 27 CFR 479.102, each 
person manufacturing or making each ``firearm''--including a ``muffler 
or silencer,'' see 26 U.S.C. 5845(a)--is required to mark the 
``firearm'' in accordance with the regulations and register it in the 
NFRTR. This rule as proposed and finalized eliminates the substantial 
cost of marking each and every individual internal part defined as a 
muffler or silencer, as well as the end cap of an outer tube. 
Additionally, under this rule, individual internal muffler or silencer 
parts may be transferred by NFA-qualified manufacturers to other 
qualified licensees for further manufacture or repair of complete 
devices without immediate registration or payment of NFA transfer tax, 
and complete devices that are registered may be temporarily conveyed 
for replacement of these internal parts. However, the term ``repair'' 
does not include replacement of the outer tube. The outer tube is the 
largest single part of the silencer, the main structural component of 
the silencer, and the part to which all other component parts are 
attached. ATF has, therefore, taken the position that the replacement 
of the outer tube is so significant an event that it amounts to the 
``making'' of a new silencer. Hence, the new silencer must be marked, 
registered, and transferred after payment of transfer tax in accordance 
with the NFA and GCA.\140\ By law, this transfer tax is owed by the 
transferor, not the government. See 26 U.S.C. 5811(b).
---------------------------------------------------------------------------

    \140\ Under this rule, the frame or receiver of a muffler or 
silencer is the part that provides housing or a structure for the 
primary internal component designed to reduce the sound of a 
projectile. Typically, this is the largest external part, or outer 
tube, without which the device would have no structure to hold the 
primary internal sound reduction component(s) and that is marked 
with a serial number, registered in the NFRTR, and for which excise 
tax must be paid. ATF has long taken the position that the creation 
of the outer tube results in the making of a new silencer, see 26 
U.S.C. 5845(i) (definition of ``make''), and the fact that a tube is 
used to replace a damaged outer tube is of no consequence because a 
functional device cannot be made without it. For this reason, the 
new regulatory text expressly excludes muffler or silencer frames or 
receivers from being transferred for replacement purposes without 
marking, recording, and registering them in accordance with 27 CFR 
parts 478 and 479.
---------------------------------------------------------------------------

h. Markings on ``Privately Made Firearms''
Comments Received
    One commenter worried that requiring firearms made from parts kits 
to be marked would destroy their value as collector's items. One 
commenter stated that the loss of tax revenue due to acquisition of 
marking equipment was not calculated in the costs described in ATF's 
RIA. Many commenters feared that FFLs would lose business because they 
do not have engraving machines and cannot work on PMFs. Several 
commenters stated that the cost of serializing a PMF ranges between $35 
and $405 based on whether the services include serializing alone or 
related services such as cleaning, oiling, bluing, polishing, or 
refinishing the firearm. One commenter stated that the per-individual 
costs in the RIA were underestimated because individuals tend to own 
more than one firearm and that the per individual cost should include 
several handguns and at least one rifle. Another commenter claimed that 
the assumption that individuals will not be charged for serialization 
is inaccurate.
    One commenter stated that the type of ``low cost, hand-embossing 
tools'' used for estimates of marking costs were not appropriate for 
marking steel or aluminum frames or receivers because the depth 
requirement may not be met, making the markings less durable. Many 
commenters asserted that a laser engraving machine would be needed to 
meet the marking requirements. One commenter stated that these machines 
cost at least $10,000 and that this type of machine is not available at 
most firearms retail stores. Many commenters were concerned that the 
estimated engraving cost of $25 is too low and suggested that the 
actual cost of engraving is between $45 and $65. One commenter was also 
skeptical of the low number of PMFs that ATF stated were in dealers' 
inventories because the agency provided no evidence as to how this 
number was determined.
    One commenter stated that the rule would ``reduce consumer value'' 
by reducing the number of available parts kits because it would hurt 
hobbyists who enjoy building their own firearms and take away the 
privacy of owning an unmarked firearm. One commenter stated that not 
all FFLs have the equipment to mark firearms and that Type 07 
manufacturers that do have the equipment may not want to mark PMFs. 
This commenter did not believe there are enough FFLs with the proper 
equipment for the number of firearms that will need to be marked. One 
commenter stated that chapter 6 of the RIA did not address the costs 
associated with recordkeeping for PMFs.
Department Response
    ATF disagrees that it needed to calculate the loss of tax revenue 
due to acquiring serializing equipment. Estimating tax revenue is 
beyond the scope of the rule and is speculative, especially since 
companies are not required to purchase equipment, much less become 
FFLs. ATF also disagrees that it did not properly estimate the total 
number of PMFs affected by the rule or that it underestimated the 
number of firearms affected per individual. Neither the proposed nor 
final rule requires the serialization of all PMFs in circulation. This 
aspect of the rule affects only firearm parts kits with a partially 
complete frame or receiver held by FFLs and PMFs that are transferred 
through an FFL; therefore, ATF account for only kits and PMFs held by 
FFLs or that may go through FFLs. However, in the final analysis, ATF 
provides an estimate of the total number of PMFs in circulation, along 
with potential costs to individuals who go through an FFL for services 
associated with marking their PMFs.
    FFLs are not required to acquire equipment to serialize firearms. 
Should they choose to receive a PMF from a non-FFL, the FFL could 
either require the individual to serialize the PMF prior to acceptance 
or directly oversee the engraving by another FFL or even a non-FFL. 
PMFs that may have been accepted into inventory prior to the effective 
date of this rule may also be outsourced for marking to a licensed 
manufacturer or gunsmith within the 60-day grace period. ATF revised 
the estimated costs to assume those with existing gunsmithing 
capabilities will perform engraving services in-house. FFLs without 
marking capabilities will either dispose of their inventory, outsource 
the inventory to another FFL that has marking capabilities, or directly 
oversee the engraving by a non-FFL. Furthermore, in the NPRM, ATF 
assumed that individuals with PMFs would not choose to undertake 
repairs or customization of their PMFs so as to avoid marking 
requirements; therefore, it did not anticipate those costs to 
individuals. Based on gunsmithing experience from subject matter 
experts from the Firearms Ammunition Technology Division, most 
individuals

[[Page 24721]]

seeking repairs or customization typically do not seek bluing or other 
services at the same time they are seeking engraving services. ATF 
concurs that the analysis in the NPRM regarding engraving was 
inaccurate. ATF agrees that a more likely scenario is that there may be 
some FFLs that sell firearm parts kits with a partially complete frame 
or receiver that also offer gunsmithing services. These FFLs will not 
need to purchase embossing equipment; rather, they can use their 
existing staff and equipment to serialize their existing inventory of 
kits. For FFLs that do not employ gunsmiths or have existing 
gunsmithing equipment, ATF estimates that these FFLs will contract out 
engraving services to another FFL, supervise the engraving services 
from a non-FFL, or dispose of their inventory. In order to simplify 
costs, ATF estimated only serialization from FFLs and not non-FFLs 
being supervised by the contracting FFL.
    ATF concurs with commenters that there would be an additional cost 
for hobbyists and has updated the economic analysis accordingly. ATF 
revisited its estimate of the cost to have multiple serial numbers on a 
firearm because, under the final rule, the definitions identify only 
one frame or receiver per firearm and therefore the vast majority of 
firearms will only have one serial number per firearm. Because only one 
regulated part will be defined as a ``frame or receiver,'' ATF 
anticipates the cost would not be prohibitive for hobbyists.
    Although FFLs are regulated, ATF does not have any records or data 
reflecting the number of weapon or frame or receiver kits with a 
partially complete frame or receiver that FFLs may have in their 
inventories. Furthermore, the Paperwork Reduction Act prevents ATF from 
surveying more than nine companies for information without going 
through the formal procedures to collect information from the public. 
See 44 U.S.C. 3502(3)(A)(i). As stated above, ATF revised the 
methodology to ascertain the number of FFLs affected and the number of 
firearm parts kit with a partially complete frame or receiver by 
relying on information from ATF's field divisions to estimate this 
population, which was determined to be the best available information 
available for the analysis.
i. Records Retention
1. Population
Comments Received
    ATF received various comments regarding the population affected by 
the cost of record retention. Some commenters stated that the cost of 
shipping all firearm records to ATF was not accounted for or that ATF's 
estimated shipping cost was too low to account for shipments from all 
FFLs. Another commenter suggested that, regardless of whether an FFL 
ships records to ATF voluntarily, all FFLs should be accounted for, not 
only the ones that currently destroy their records that are over 20 
years old. One commenter stated that ATF should have done an advanced 
notice of proposed rulemaking to find out the number of FFLs that 
retain their records for more than 20 years instead of relying on 
subject matter expert estimates. The commenter also believed that ATF's 
estimate that less than 10 percent (or 5,407) of dealers and collectors 
are not retaining their records beyond 20 years is too low because the 
RIA lists the number of FFLs at 113,204, and 10 percent of this number 
is 11,320, which is twice what is listed in the RIA.
Department Response
    The Department disagrees with commenters who said the agency 
underestimated the cost per FFL and that it should have taken into 
account the costs borne by all FFLs. Federal law, see 18 U.S.C. 
923(g)(4); 27 CFR 478.127, already requires FFLs to send all of their 
out-of-business records to ATF. ATF does not consider these costs as 
attributable to the rule because the duty to send out-of-business 
records to ATF is an existing statutory and regulatory requirement. In 
the NPRM, ATF estimated that most FFLs currently store records beyond 
20 years and will not be affected by the indefinite records retention 
requirement. As described below, the cost burden for extending the 
record retention requirement will affect only a subset of the total 
number of FFLs. Furthermore, the Office of Management and Budget 
(``OMB'') explains that the baseline for measuring a rule's costs 
should be ``what the world will be like if the proposed rule is not 
adopted.'' \141\ Prior to the publication of the NPRM, the majority of 
FFLs maintained records until discontinuance of business or licensed 
activity regardless of whether they remained in business for 20 years 
or not. Because any alternative, including the proposed rule, would be 
a comparison against this baseline, only the incremental cost above 
this baseline is attributed to this rule.
---------------------------------------------------------------------------

    \141\ OMB, Circular A-4 at 2 (Sept. 17, 2003), available at 
https://www.whitehouse.gov/wp-content/uploads/legacy_drupal_files/omb/circulars/A4/a-4.pdf (last visited Mar. 23, 2022).
---------------------------------------------------------------------------

    The 113,204 total number of FFLs is for all types of FFLs at the 
time of the analysis. Records retention affects a subset of all FFLs, 
in particular, Type 01 and Type 02 FFLs, because licensed manufacturers 
(Types 06, 07, and 10) and importers (Types 08 and 11) generally 
maintain permanent consolidated production, acquisition, and 
disposition records in accordance with 27 CFR 478.129(d) and ATF 
Rulings 2011-1 and 2016-3. Additionally, ATF estimates that licensed 
collectors (Type 03) generally maintain their curio or relic collection 
records until discontinuance of licensed activity. At the time of the 
NPRM, there were only 60,079 Type 01 and 02 FFLs, and of those, fewer 
than 10 percent were estimated to be destroying their records that were 
more than 20 years old. In the RIA for the final rule, ATF reiterates 
that records retention primarily affects Types 01 and 02 FFLs, and thus 
not all FFLs are listed in the overview of the analysis.
2. Costs
Comments Received
    Various commenters suggested that the new reporting requirements 
alone should have made the rule economically significant. Commenters 
suggested that ATF did not account for the influx of transactions 
records for multiple ``frames'' or ``receivers'' or the influx of 
transaction records from purchases of firearm parts kit with a 
partially complete ``frame or receiver'' that would be disposed of as a 
``firearm'' under the rule. Similarly, one commenter suggested ATF 
should use NICS checks and population growth models to account for the 
increased number of transactions and number of records in the future.
    One commenter suggested that, in 2018, nine million firearms were 
manufactured. Accounting only for nine million firearms, the cost 
burden per record was estimated to be $0.02 per record. One commenter 
argued that the NPRM's cost estimate of $68,939 does not realistically 
encompass the recordkeeping requirements for all 79,869 FFLs because 
the number of records retained and therefore submitted will grow over 
time. This commenter further suggested that, based on the NPRM estimate 
of $68,939 for the entire industry, the per shipment cost for all 
records over 20 years would be $0.86 per FFL, which the commenter 
asserted was too low. Other commenters stated that the RIA estimated 
only additional storage costs for ATF but not the costs to FFLs.

[[Page 24722]]

    Several commenters suggested that the NPRM did not account for the 
increase in the number of records FFLs will have to maintain due to the 
increased number of transactions likely to happen if a firearm has 
multiple serial numbers. One estimated that the recordkeeping burden 
for ATF Forms 4473 would increase by 437 million.
    One commenter stated FFLs that have voluntarily retained records 
beyond 20 years will have a greater cost of storing records 
indefinitely than FFLs that destroyed or surrendered records older than 
20 years because the FFLs that retained their records will overall have 
more records that will need to be stored. This commenter believed that 
the rule change will encourage FFLs to destroy records beyond 20 years 
prior to the change, which will hurt ATF's ability to trace firearms.
    One commenter estimated that it would cost the firearms industry 
$8.1 billion to develop and secure electronic records and that it would 
cost ATF $546 million annually to maintain and support electronic 
storage of records. Several commenters suggested that the low records 
retention cost described in the RIA was due to an over-reliance on 
savings from converting paper records to electronic storage. One 
commenter suggested that the cost for electronic storage should include 
a team of employees to create and maintain electronic storage for the 
FFL.
    One commenter suggested that ATF relied too heavily on subject 
matter experts for assumptions used in the RIA and noted that the 
experts' methodologies were unknown to the public. Furthermore, this 
commenter questioned the assumption that all FFLs would send their 
records older than 20 years to ATF. One commenter suggested that ATF 
consider an alternative to this requirement with a time frame between 
20 years and indefinite.
Department Response
    The Department did not account for the potential increase in the 
number of records stored due to an increase in transactions recorded 
for multiple ``frames'' or ``receivers;'' however, this cost no longer 
needs to be accounted for as a result of changes to the definition of 
firearm frame or receiver. Nonetheless, the Department concurs that 
there will be an increase in firearms records because there could be 
more firearms transactions; this could increase the overall record 
retention cost. There were 14 million NICS checks in 2010 and almost 40 
million NICS checks in 2021. In the cost section of chapter 7 of the 
RIA, ATF forecasts the estimated increase in Form 4473 applications 
based on the number of reported NICS checks and NFA applications by 
year and estimates the increase in shipping costs for FFLs to send 
their records to ATF when their business or licensed activity is 
discontinued.
    Under the initial RIA, the $68,939 cost to retain records beyond 
the existing 20-year requirement was not distributed among the total 
113,204 FFLs. ATF subject matter experts report that most FFLs already 
retain records indefinitely beyond the existing 20-year requirement 
until discontinuance of business or licensed activity. For most FFLs, 
this practice is already an industry standard and thus the cost of this 
practice is not attributable to this rule. Therefore, as stated in the 
NPRM and the final rule, not all FFLs will incur recordkeeping costs as 
a result of this rule's implementation. However, ATF agrees that there 
may be some FFLs that do not maintain records indefinitely or that 
transfer their records to a successor FFL. These FFLs may now incur 
additional recordkeeping costs to comply with this rule. Costs were 
estimated for these FFLs and ATF has revised the final analysis.
    Because FFLs are required by 18 U.S.C. 923(g)(4) and 27 CFR 478.127 
to send all of their records to ATF upon absolute discontinuance of 
their business or licensed activity, ATF does not consider costs for 
FFLs to ship their records to ATF upon such a discontinuance to be a 
cost of this rule; instead, it is a cost of the existing requirement in 
18 U.S.C. 923(g)(4) and 27 CFR 478.127. ATF did not receive comments 
that would otherwise contradict the recordkeeping analysis; therefore, 
the NPRM cost analysis remains the same.
    Most FFLs have and will continue to retain records, and this rule 
will not affect these FFLs. As stated above, most FFLs retain records 
for more than 20 years. This existing activity pre-dates the final 
rule, and costs of this activity thus are not attributable to the rule. 
However, the small number of FFLs that currently destroy records older 
than 20 years could incur some costs. For purposes of the final RIA, 
ATF estimates that, in an effort to reduce their costs, these FFLs may 
utilize electronic storage. Furthermore, most FFLs that use electronic 
formats of A&D records or electronic Forms 4473 outsource these 
software applications to a third party rather than hiring staff and 
building the program in-house; therefore, ATF is not incorporating the 
cost for an FFL to create and maintain electronic storage of their 
records.
    ATF uses subject matter experts as the best available information 
when it lacks data because there is no requirement to regulate or track 
certain activities or items. However, ATF was able to use trace data 
and out-of-business records as a proxy to estimate the number of FFLs 
that do not retain records older than 20 years and that therefore could 
be affected by this rule. For this final rule, ATF determined this to 
be the best available information. Also, in its final analysis, ATF 
revised the costs for FFLs that currently voluntarily ship records 
older than 20 years. Upon promulgation of this rule, these FFLs will no 
longer be able to ship their records to ATF that are older than 20 
years without discontinuing business or licensed activity. However, 
shipping out-of-business records remains an option should these FFLs 
choose to discontinue their current licensed business or activity and 
apply for a new license for a business that maintains an electronic 
recordkeeping system so that they may dispose of their paper records to 
ATF.
3. Benefits
Comments Received
    Some commenters stated that ATF did not quantify or monetize 
benefits for the record retention requirement. One commenter suggested 
that the benefits do not outweigh the costs. One commenter asserted 
that ATF did not demonstrate how many crimes would be solved through 
tracing firearms over 20 years old. Some commenters believed that, with 
records older than 20 years, ATF would be unable to identify the most 
recent owner of the firearm because too much time would have passed, 
and this would lead to increased failures in tracing. One commenter 
believed ATF failed to meet the requirements of the APA because it did 
not explain how electronic records would lower the cost of storing 
records, nor did ATF explain why it did not include this information.
Department Response
    Tracing a firearm that was involved in a criminal activity is an 
existing requirement and not a new requirement attributable to this 
rule. Based on the amount of records previously received by the NTC, 
ATF anticipates the cost burden for this requirement will be small. 
Commenters are incorrect in their assumption that the rule would lead 
to an increased rate of failed traces because the records are too old. 
To the contrary, being able to trace a firearm to the first unlicensed 
transferee of the firearm from a firearms licensee, no matter how

[[Page 24723]]

long ago, provides useful investigative leads to law enforcement. 
Furthermore, this final rule now includes, in Section IV.B.5.d of this 
preamble, information on the number of traces submitted over the past 
12 years that could not be successfully completed because the licensee 
informed ATF it did not have the record for that firearm because the 
record was more than 20 years old and had been destroyed.
    ATF disagrees with respect to putting forth additional analysis 
regarding electronic storage. The option for electronic storage is an 
existing option and this rule only expressly codifies and expands that 
option for licensees in an alternate method approved by the Director. 
See ATF Rul. 2016-1; ATF Rul. 2016-2. Specifically, it is anticipated 
that the option for maintaining electronic storage of ATF Forms 4473 
will be updated via an ATF Ruling issued contemporaneously with this 
final rule.
j. Form Updates
Comments Received
    Commenters asserted that the cost to update software for electronic 
recordkeeping was understated. Some commenters feared that it would 
cost a significant amount of money to update existing software to track 
multiple serial numbers because current systems allow for only a single 
serial number. Other commenters stated that some FFLs would need to 
acquire new software systems because the existing systems may no longer 
be supported by the original developer to make updates. Some commenters 
suggested that ATF did not account for extra time needed to enter 
multiple serial numbers into records.
Department Response
    ATF concurs that, based on public comments, it would likely cost a 
significant amount of money to revamp software programs to account for 
multiple serial numbers. For this and other reasons, ATF has revised 
the definition of ``frame or receiver'' so that it describes a single 
part of a weapon as the frame or receiver, meaning that generally only 
one serial number would need to be recorded per firearm in the same 
manner as under current regulations. The rare exceptions would be if a 
manufacturer or importer chooses not to adopt an existing serial number 
on a firearm that is remanufactured or imported, or if a multi-piece 
frame or receiver had been assembled from modular subparts with 
different serial numbers marked on the same frame or receiver. 
Therefore, no cost was attributed to this requirement.
k. Government Costs
Comments Received
    Many commenters stated that the government would incur additional 
costs associated with lawsuits filed against the rule. Some commenters 
worried that States will lose sales and tax revenue because companies 
will go out of business. Other commenters expressed concern that the 
government would spend more money arresting and incarcerating law-
abiding people who they believed would become criminals under this 
rule. One commenter stated that the rule would lead to increased cost 
to the government because the government would need additional 
personnel, equipment, and training to enforce the rule.
Department Response
    The Department did not account for the cost of lawsuits because 
costs due to potential lawsuits would be speculative. Although ATF 
estimated there could be a number of businesses that go out of 
business, there is no guarantee of accuracy in the number of businesses 
that would go out of business due to implementation of the rule; 
therefore, ATF deemed it too speculative to estimate a loss in tax 
revenue. Furthermore, ATF is not spending more money to arrest people 
who make and possess PMFs as a result of this rule. As stated earlier, 
nothing in this rule prevents unlicensed law-abiding citizens and 
hobbyists from making their own firearms by using commercially produced 
parts or by using 3D printers; or from transferring PMFs to others as 
long as they are not engaged in a business or activity requiring a 
license. If such persons wish to engage in the business of 
manufacturing, importing, or dealing in firearms, they must obtain a 
license like any other manufacturer, importer, or dealer.
l. Lack of Benefits
Comments Received
    Many commenters claimed that the assertion that PMFs are used in 
crimes is not supported by the BJS survey on how criminals acquire 
firearms (referenced earlier in Section IV.B.8 of this preamble), and 
that the rule's asserted benefits are not supported by the FBI's 
Uniform Crime Statistics. Many commenters stated that firearms are used 
in a small percentage of crimes. They claimed that the number of 
firearms recovered at crime scenes is low and not all perpetrators are 
arrested and convicted. One commenter stated that the RIA failed to 
show why the lack of serial numbers is important to criminals and did 
not consider other methods that the criminal may use (removing a serial 
number or using a different type of weapon) to circumvent the new 
requirements. Another commenter asserted that there is no evidence that 
PMFs are the weapon of choice for criminals.
    Many commenters argued that ATF did not show how the proposed rule 
would reduce crime. Some commenters stated the NPRM did not indicate 
the number of traces that identified the perpetrator, resulted in an 
arrest, or substantially affected the prosecution of the criminal. Nor 
did it provide the percentage of unserialized firearms used in crimes 
or show how many crimes could be solved if PMFs could be traced. A 
commenter asserted that, if the data is available, the public should be 
able to comment on it. Another commenter pointed to studies that 
suggest that firearms restrictions do not have an impact on gun 
violence. One commenter argued that the tracing of serialized firearms 
has failed to reduce deaths caused by these weapons.
    Another commenter stated that the majority of firearms traces are 
for weapon offenses, not violent crimes such as homicides, assaults, or 
robberies. ``Mere weapon offenses,'' according to the commenter, 
``cause no immediate harm,'' and ``thus the vast majority of traces do 
not involve the remediation of many violent uses of guns.'' The 
commenter also argued that the ``costs of failing to obtain a 
conviction on a weapon offense [are] minuscule,'' especially because 
``the perpetrator will likely be convicted of some other associated 
crime.'' This commenter also stated that ATF failed to show how an 
increase in traces would lead to increased arrests and convictions and 
that ATF did not provide a monetary benefit of this supposed increase. 
Because only a small number of firearms required to be marked under 
this rule will ever be traced, according to the commenter, the 
``external costs'' of failed tracing are low and do not support the 
burden of the rulemaking. Another commenter argued that homicides 
committed with PMFs would be a very small portion of cases that would 
be addressed by this rule, while another commenter claimed that it 
would take 30 years of homicides committed with PMFs to equal one year 
of homicides committed with serialized firearms.
    One commenter stated that, although ATF reported the number of 
traces that include suspected PMFs and the

[[Page 24724]]

number of homicides related to the usage of PMFs, ATF did not attempt 
to monetize these deaths and injuries. Another commenter stated that 
ATF failed to show the value or benefits, either individually or on the 
whole, of regulating firearms kits with a partially complete frame or 
receiver or unassembled frames and receivers and related parts kits. 
One commenter stated that ATF failed to explain why it cannot monetize 
or quantify the purported benefit of consistent marking requirements. 
The commenter stated that the agency failed to explain who benefits and 
how large the benefits are, thus not meeting its burden under the APA. 
The commenter argued that ATF could have provided the benefit of easing 
marking requirements without adding additional marking requirements.
    One commenter stated that there is no need for regulation because 
PMF owners can voluntarily mark their firearms. If they choose not to, 
the commenter said, it is because they do not find a benefit in it and 
only hurt themselves if the firearm is lost or stolen. The commenter 
also stated that ATF failed to provide information on the number of 
lost or stolen PMFs or parts kits and the number of these firearms or 
kits that could not be returned to the legal owner due to the lack of a 
serial number. Additionally, the commenter said ATF failed to show how 
often criminals receive PMFs using a straw purchaser. Another commenter 
argued that the rule will not deter straw purchasers.
Department Response
    The Uniform Crime Statistics referenced by commenters are compiled 
through the FBI's Uniform Crime Reporting (``UCR'') Program. The UCR 
Program, however, does not collect crime information on PMFs. As a 
result, ATF did not rely upon UCR Program data to explain the rise in 
suspected PMFs that are recovered and traced from crime scenes. FBI 
Uniform Crime Statistics were not considered pertinent for present 
purposes and were not used in analyzing the costs and benefits of this 
rule.
    Furthermore, based on tracing and National Integrated Ballistics 
Information Network data, many law enforcement agencies may not be 
reporting PMFs accurately, and therefore, ATF believes that the number 
of PMFs reported as being used in crimes is significantly smaller than 
the actual number. Aware of these potential reporting errors, the 
number of PMFs ATF has presented in the RIAs accompanying the NPRM and 
this final rule is likely to be much lower than the actual number 
recovered. ATF did, however, provide more quantifiable benefits in the 
final RIA based on an increased ability to trace all firearms, and 
particularly, PMFs. ATF reiterates that the primary benefit of the 
final rule is promoting public safety and restricting felons and other 
prohibited persons' access to firearms.
m. Proposed Alternatives
Comments Received
    Thousands of commenters claimed that ATF did not mention any one of 
the regulatory alternatives proposed by the wider firearms industry 
that several commenters believe were raised with ATF during an early 
2021 meeting reported by the Wall Street Journal. See Zusha Elinson, 
Ghost-Gun Concerns Prompt Feds to Meet With Firearms Makers, Wall St. 
J. (Mar. 26, 2021), available at https://www.wsj.com/articles/ghost-gun-concerns-prompt-feds-to-meet-with-firearms-makers-11616756403 (last 
visited Mar. 23, 2022). Other commenters asserted that ATF failed to 
adequately consider or explain why it was not considering the 
regulatory alternatives provided in the NPRM. For example, one industry 
member stated that, of its four regulatory alternatives, ATF did not 
explain regulatory alternative number one, which was no change, and 
regulatory alternative number three, which was to grandfather all 
existing firearms. For instance, the commenter stated that ATF did not 
explain for alternative number three why it would be difficult to bring 
enforcement actions against the continued manufacturing of noncompliant 
receivers or explain why the burden of doing so would not be justified 
by the alleged fact that there are ``no costs'' associated with the 
third option's implementation.
    Numerous commenters opposed to the NPRM stated that ATF should 
grandfather in all personally owned items to preserve citizens' civil 
liberties and to avoid criminal entrapment. Some commenters suggested 
that ATF allow non-FFLs to continue selling unfinished lower receivers 
while placing the burden on the consumer to register the firearm with 
an FFL once the consumer completes the process of privately 
manufacturing a lower receiver. The commenter argued that it is 
illogical to require manufacturers and retailers of unfinished lower 
receivers to adhere to a regulatory system that is a ``veiled scheme of 
forced compliance against gun owners.'' In the commenter's opinion, 
only when an unfinished lower receiver is finished by the end user can 
the final owner be identified and the markings be completed and known 
(e.g., gauge or caliber).
    One commenter suggested that ATF consider non-regulatory 
alternatives such as corrective taxes and subsidies, aid from non-
governmental organizations, tort law, public service advocacy, and 
private contracting. Another commenter suggested that ATF consider 
other alternatives, such as requiring that records be retained for 
longer than 20 years (but less than indefinitely) or allowing anyone to 
mark weapons.
Department Response
    The Department disagrees with commenters who stated that ATF did 
not consider regulatory alternatives proposed by the wider firearms 
industry during an early 2021 meeting reported by the Wall Street 
Journal because ATF was not presented with any regulatory alternatives 
other than keeping the current limited and outdated definitions.
    The ``no change'' alternative has no costs or benefits because it 
would involve maintaining the status quo. This alternative was 
considered but not implemented because the GCA requires that all 
firearms be regulated. Currently, the vast majority of firearms fall 
outside the scope of the existing regulatory definition of ``frame or 
receiver.'' Due to recent court rulings, it would be difficult for the 
Department to continue to successfully prosecute criminal activity 
relying on the existing regulatory definition of ``frame or receiver'' 
because that definition does not capture the vast majority of firearm 
designs.
    With respect to grandfathering all existing firearms, the proposed 
rule sought to allow manufacturers and importers to mark firearms of 
the same design and configuration in the same manner as before the 
effective date of the final rule. The final rule makes clear that 
almost all firearms ATF previously classified as falling within the 
definition of ``frame or receiver'' prior to issuance of the final rule 
are grandfathered and may continue to be marked in the same manner as 
before the effective date of the final rule. The only exceptions are 
certain ATF classifications of partially complete, disassembled, or 
nonfunctional frames or receivers because, at the time of 
classification of those articles, ATF may not have been provided with, 
or did not examine, a full and complete parts kit containing those 
items along with any associated templates, jigs, molds, equipment, 
tools, instructions, guides, or marketing materials that were made 
available by the seller or distributor of the item or kit

[[Page 24725]]

to the purchaser or recipient of the item or kit. As explained in this 
final rule, these items and materials are necessary for ATF and others 
to make a proper firearm classification under the GCA and NFA (if 
applicable).
    To clarify, existing firearm parts kits with a partially complete 
frame or receiver, and PMFs owned by or serviced by FFLs that were 
determined not to be ``frames or receivers'' as defined prior to this 
rule, will not be grandfathered in, meaning that FFLs may be required 
to mark these firearms in accordance with the new regulations if the 
FFLs wish to maintain them in their inventories. This rule does not 
require unlicensed PMF owners to do anything to their firearms 
maintained solely for personal use.
    ATF has determined that the ``non-regulatory alternative'' of 
imposing a higher tax on firearms that are currently being regulated 
would only make the cost of regulated firearms more expensive to the 
public and would not affect the PMFs or firearm parts kits that 
currently fall outside of the regulatory regime. Subjecting firearms to 
higher taxes would not ensure that all firearms, whether commercially 
or privately made, are treated the same under the regulations when they 
enter interstate commerce. This in turn would not achieve ATF's 
objectives of ensuring that felons and prohibited persons are not able 
to obtain firearms and that firearms can be traced. The objective of 
this rule is not to make firearms more expensive or more difficult for 
the public to obtain; rather, the objectives of the rule are to ensure 
that all firearms, as defined by the GCA, are regulated similarly; to 
remove the current regulatory definitions of ``frame or receiver'' and 
replace them with definitions that capture the vast majority of firearm 
designs and advancements in firearms technology; to allow law 
enforcement to trace firearms, including PMFs; and to prevent felons 
and other prohibited persons from easily acquiring firearms. It is not 
clear how implementing corrective taxes would prevent criminals from 
obtaining firearms or help law enforcement officers solve crimes.
    It is not clear how the commenter's suggested alternative scenarios 
using non-regulatory alternatives (e.g., tort or public advocacy) would 
be carried out. However, these alternatives are out of ATF's purview 
and beyond the scope of this regulation; therefore, these alternatives 
were not considered.
    Although the alternative of requiring record retention for longer 
than 20 years, but less than indefinitely, was considered, ATF 
determined that this alternative was not the best course of action. 
Because firearms are durable items that can be in circulation for many 
decades or even beyond 100 years, an alternative specifying a specific 
time frame for record retention requirements would not align with the 
shelf life of most firearms. Thus, without the indefinite retention 
requirement imposed by this rule, ATF would continue to encounter the 
problem of not being able to successfully trace older firearms that are 
used in the commission of a crime. As a result, ATF does not believe 
such alternatives would achieve the intended benefits of this final 
rule.
n. Final Regulatory Flexibility Analysis
Comments Received
    Many commenters asserted that the rule will have a significant 
impact on small businesses. Other commenters argued that a robust small 
business analysis was not performed. Some commenters stated that the 
rule will have a negative impact on many small businesses, including 
those owned by veterans and families. They further stated the rule 
would impact businesses that sell firearms parts as well as those that 
specialize in firearms customization.
    A major distributor of firearms parts pointed out that ATF failed 
to explain how there can be a significant financial impact on 
individual businesses but not all the businesses in the same industry. 
One commenter listed multiple reasons the Initial Regulatory 
Flexibility Act (``IRFA'') was, in the commenter's opinion, not done 
according to law. The reasons included a lack of a statement of 
objectives and legal basis for the proposed rule; a lack of evidence 
that the 132,023 affected entities would experience minimal or no cost; 
a failure to accurately estimate the affected population of non-FFL 
retailers; a lack of sufficient analysis on the impact on non-FFL 
retailers; and a failure to provide sufficient analysis of the impact 
on the unfinished lower receiver market. The commenter stated that 
there was no analysis addressing the cost of becoming licensed or 
providing options that would have the same result as regulation. 
Additionally, the commenter believed the market for unfinished 
receivers would be quickly diminished. One commenter stated that the 
IFRA analysis contained errors, such as ATF's failure to monetize or 
quantify benefits or explain why it did not do so and ATF's dismissal 
or underestimation of costs.
    One commenter asserted that the rule has ``net negative benefits'' 
so it should not move forward. The commenter believed that the change 
in record retention requirements would result in fewer successful 
firearm traces because of the increased number of documents retained. 
Several commenters stated that ATF failed to provide the actual number 
of small businesses that would be affected and the estimated costs that 
the affected entities would incur.
    Some commenters stated that manufacturers of unfinished receivers 
and firearm parts kits with an unfinished frame or receiver would 
choose not to obtain an FFL and instead go out of business. This would 
hurt firearms manufacturers because they purchase these items as part 
of their production process. Several commenters suggested that this 
rule will result in significant job losses in manufacturing. One 
commenter stated that this rule would affect his ability to expand his 
business and another commenter stated that it had put off business 
expansion and new hiring because of the rule. Another commenter stated 
that, because of the anticipated increase in the price of unfinished 
receivers as a result of the rule, he would no longer be able to 
provide classes in firearms safety, maintenance, and marksmanship.
    One commenter stated that the real cost of the proposed rule is not 
the lost revenue of the affected companies but the loss in the value of 
these companies, which hurts the companies' owners. The commenter also 
stated that ATF failed to show the anticipated number of jobs lost and 
the value associated with the loss.
    Many commenters asserted that ATF underestimated the cost to the 
industry. One commenter stated that small businesses would need to 
acquire engraving equipment and inventory tracking systems. Those 
businesses that could not afford this expense, according to the 
commenter, would be forced to destroy inventory. One commenter stated 
that both large and small entities would need to spend time and money 
to ensure compliance with the new regulations. One commenter argued 
that ATF did not consider the true cost to non-manufacturing FFLs for 
equipment purchases and training, and for the volume of PMFs needing 
serialization to recoup the return on the investment.
Department Response
    ATF agrees that different entities will experience a range of costs 
as outlined by the different chapters of the RIA, and ATF revised the 
regulatory flexibility analysis to describe the largest impact on small 
businesses, which is that some businesses will no longer continue

[[Page 24726]]

operations. The IRFA has been updated to reflect these costs.
    ATF concurs that large and small entities may require time to 
research and understand regulations. However, this is already an 
existing cost of regulations in this industry in general and is not a 
new requirement specific to this rule. Therefore, it is not considered 
a cost of this rule. In accordance with the Small Business Regulatory 
Enforcement Fairness Act (``SBREFA''), a small business compliance 
guide will be published because this final rule will impact a 
significant number of small businesses.
o. APA Requirements
Comments Received
    One commenter suggested that this rule should be considered both a 
regulatory and economically significant rule because of its impact on a 
substantial number of small businesses, as indicated in the RIA. 
Another commenter believed that the rule violated Executive Order 
12866.
Department Response
    As stated in the NPRM, this rule is a ``significant regulatory 
action'' under section 3(f)(4) of Executive Order 12866; however, this 
rule is not ``economically significant,'' as that term is defined in 
the Executive Order. An ``economically significant'' rule is one 
estimated to cost $100 million or more in one given year. This rule is 
not expected to reach that threshold. As discussed in the Final 
Regulatory Flexibility Analysis (``FRFA''), ATF agrees that this rule 
could potentially affect small businesses that only manufacture or deal 
in firearm kits with a partially complete frame or receiver, but notes 
that whether a rule has significant impacts on small businesses does 
not determine if the rule is economically significant under Executive 
Order 12866. Nevertheless, because this rule has the potential to 
significantly affect small businesses, ATF has performed an IRFA and a 
FRFA.
p. Congressional Review Act
Comments Received
    One commenter disagreed with the Department's claim in the NPRM 
that this rulemaking is not a ``major rule,'' which is defined in 5 
U.S.C. 804(2), in part, as a rule that ``resulted in or is likely to 
result in . . . an annual effect on the economy of $100,000,000 or 
more'' or; ``significant adverse effects on . . . innovation.''
Department Response
    ATF disagrees that this this is a ``major rule'' as defined under 5 
U.S.C. 804(2). This rule is estimated to cost less than $100 million in 
any given year, as outlined in the standalone RIA. Further, the 
Department disagrees this rule stifles or impacts innovation. To the 
contrary, the regulations are being updated to accommodate changes in 
firearms technology and terminology, and the industry may develop new 
innovations to comply with the updated regulations.
q. Unfunded Mandate
    One commenter believed that the rule would exceed the one-year 
allowable threshold of $177 million (adjusted for inflation since 1995) 
set by the Unfunded Mandates Reform Act. See 2 U.S.C. 658c.
Department Response
    ATF disagrees that the rule will be a major rule under the Unfunded 
Mandates Reform Act. The rule is estimated to cost less than $100 
million in any given year, as outlined in the standalone RIA.
14. Other Concerns With the Rule
a. Comment Process
Comments Received
    At least one commenter claimed that there were concerns in online 
groups and boards that a number of comments meeting the guidelines for 
being publicly posted were ``subsequently deleted,'' thus ``forcing 
people to issue new comments for the rule,'' or that comments were 
moderated prior to publishing, raising a free speech concern. The 
commenter stated that, although these comments might have contained 
offensive language or have included threats, or may have been similar 
to other comments indicating spam, those comments should still have 
been considered as either supporting or opposing the proposed rule. 
Another commenter stated that the agency's instructions that commenters 
self-identify and provide contact information ``severely limit the 
degree and amount of public participation.'' They also argued that 
these instructions chilled speech protected by the First Amendment and 
discouraged members of the public from commenting. Because of this, the 
commenter stated that ATF should re-open the comment period.
Department Response
    ATF received just over 290,000 comments during the 90-day comment 
period. The vast majority of comments were received through the online 
Federal portal (www.regulations.gov) with the balance coming through 
mail and fax. The NPRM's Public Participation section informed the 
public that there may be a significant delay between the time a person 
submits a comment through one of the three methods before it becomes 
visible online due to the volume of comments received on any given day. 
The Federal Docket Management System (``FDMS''), the portal through 
which Federal agencies manage their rulemaking dockets, requires the 
agency to review comments before making them visible to the public on 
regulations.gov. With the exception of a limited ability to redact, 
FDMS does not allow agency users of the system to alter or change the 
substance of a comment. ATF posted and reviewed comments, even numerous 
duplicate comments (i.e., comments from the same submitter with the 
same content) that were generally consistent with the posting 
guidelines, i.e., comments that did not contain excessive profanity or 
contain inappropriate or sensitive content. No comments were deleted or 
removed, unless upon request of a submitter.
    The Department disagrees that ATF's instructions that commenters 
self-identify ``severely limit the degree and amount of public 
participation,'' chill speech, or discourage the public from 
commenting, as evidenced by the volume of comments received on the 
NPRM, as well as the content of some comments that expressly declared 
that they will not comply with any regulation. ATF has historically 
requested persons to self-identify and include contact information 
largely in the event that a person makes a comment that the agency 
would like to follow up on to gain further information or perspective 
from the commenter. There were recent updates to the online Federal 
portal that allowed the public to submit comments under an 
``Anonymous'' feature; ATF accepted, posted, and considered these 
comments. Accordingly, the Department disagrees that ATF should re-open 
the comment period.
b. No Federalism Impact Statement
Comments Received
    At least one commenter asserted that ATF should have prepared a 
federalism summary for the NPRM pursuant to Executive Order 13132, 
entitled ``Federalism.'' This Executive Order is a directive meant to 
``guarantee the division of governmental responsibilities between the 
national government and the States'' and ``further the policies of the 
Unfunded

[[Page 24727]]

Mandates Reform Act.'' \142\ Under Section 6 of the Executive Order, 
agencies are not permitted, to the extent practicable and permitted by 
law, to issue any regulation that has ``federalism implications'' \143\ 
if the regulation imposes substantial direct compliance costs on State 
and local governments and is not required by statute, or if the 
regulation preempts State laws, unless the agency consults with State 
and local officials and prepares a federalism impact summary.
---------------------------------------------------------------------------

    \142\ 64 FR 43225 (Aug. 10, 1999).
    \143\ ``Policies that have federalism implications'' are defined 
as ``regulations . . . that have substantial direct effects on 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among 
the various levels of government.'' E.O. 13132, sec. 1(a).
---------------------------------------------------------------------------

    The commenter argued that, although the NPRM acknowledged that 
States have chosen different policymaking paths to regulate or not 
regulate PMFs or kits, the Department and ATF failed to engage in a 
federalism analysis of its ``constitutional and statutory authority for 
[its] action'' in accordance with section 3(b) of the Executive Order. 
That section requires such analysis and consultation with State or 
local officials if the agency's action limits the policymaking 
discretion of the States and if ``there are significant uncertainties 
as to whether national action is authorized or appropriate.'' The 
commenter further argued that, pursuant to section 4(a) of the 
Executive Order, the NPRM failed to acknowledge that the Federal re-
definition of ``firearm'' and mandated marking requirements would 
preempt State laws, such as State laws on the storage and 
transportation of firearms and on the marking or registration of PMFs. 
Finally, the commenter observed that State laws often rely on Federal 
classifications. For all these reasons, according to the commenter, 
States might be directly affected by the NPRM.
Department Response
    The Department disagrees that a federalism impact statement is 
needed for this rulemaking under Executive Order 13132. This rule, 
which implements the GCA, does not preempt State laws or impose a 
substantive compliance cost on States. Under the GCA, 18 U.S.C. 927, 
State and local jurisdictions may enact their own requirements and 
restrictions on firearms unless there is a direct and positive conflict 
such that the two cannot be reconciled or consistently stand together. 
State and local jurisdictions are therefore free to create their own 
definitions of terms such as ``firearm'' and ``frame or receiver'' to 
be applied for purposes of State or local law within their respective 
jurisdictions. They are free to mandate their own requirements 
concerning the marking, storage, sale, and transportation of 
firearms.\144\ This rule points out that numerous State and local 
jurisdictions have, in fact, enacted their own restrictions on 
unmarked, unserialized, 3D-printed, or undetectable firearms, and 
firearms with obliterated, removed, or altered serial numbers, and have 
adopted requirements to report or record the serial number marked on 
pawned firearms.\145\ This rule as proposed and finalized does not 
purport to impose any costs upon or otherwise limit the authority of 
State and local governments. To the contrary, the GCA and NFA 
implementing regulations at 27 CFR 478.58 and 479.52, which are not 
being amended, expressly state that holders of Federal firearms 
licenses and NFA taxpayers are not conferred any right or privilege to 
conduct business or activity contrary to State or other law, and that 
they are not immune from punishment for conducting a firearm or 
ammunition business or activity in violation of State or other law.
---------------------------------------------------------------------------

    \144\ See 18 U.S.C. 922(b)(2) (making it unlawful for a licensee 
to sell or deliver any firearm to any person in any State where the 
purchase or possession by such person would violate any State law or 
published ordinance); 18 U.S.C. 923(d)(1)(F) (requiring license 
applicants to certify compliance with State and local law).
    \145\ See footnotes 24, 35, and 121, supra; see also 86 FR at 
27730 n.62. However, State and local jurisdictions are not entitled 
to redefine, amend, or exempt persons from the provisions of Federal 
law.
---------------------------------------------------------------------------

V. Final Rule

A. Definition of ``Firearm''

    The rule finalizes, with minor changes, the amendments proposed in 
the NPRM to the definition of ``firearm'' in part 478, which clarify 
that this term includes a weapon parts kit that is designed to or may 
readily be completed, assembled, restored, or otherwise converted to 
expel a projectile by the action of an explosive.

B. Definition of ``Frame or Receiver''

    The final rule accepts the recommendations of numerous commenters 
and provides a new definition to remove and replace the terms ``firearm 
frame or receiver'' and ``frame or receiver'' in Sec. Sec.  478.11 and 
479.11 (referencing Sec.  478.12). The new definition, set forth in a 
new Sec.  478.12, separately defines ``frame'' for handguns, and 
``receiver'' for rifles, shotguns, and other weapons that expel a 
projectile other than handguns. Rather than a definition that describes 
any housing for any fire control component, these definitions now 
describe only a single housing or structural component for one specific 
fire control component of a given weapon including ``variants 
thereof,'' a term that is also defined. For handguns, or variants 
thereof, it is the housing or structure for the primary energized 
component designed to hold back the hammer, striker, bolt, or similar 
component prior to initiation of the firing sequence (i.e., sear or 
equivalent), even if pins or other attachments are required to connect 
such component to the housing or structure. For rifles, shotguns, and 
projectile weapons other than handguns, or variants thereof, it is the 
housing or structure for the primary component designed to block or 
seal the breech prior to initiation of the firing sequence (i.e., bolt, 
breechblock, or equivalent), even if pins or other attachments are 
required to connect such component to the housing or structure.
    The final rule amends the definitional supplement to ``frame or 
receiver'' entitled ``firearm muffler or silencer frame or receiver'' 
to define a single component of a complete firearm muffler or silencer 
device as the frame or receiver, and clarifies how the definition 
applies to a modular device with more than one housing or structure for 
the primary internal sound reduction components. Specifically, the 
terms ``frame'' and ``receiver'' mean the housing or structure for the 
primary internal component designed to reduce the sound of a projectile 
(i.e., baffles, baffling material, expansion chamber, or equivalent) 
(formerly, ``essential internal components''). Additionally, the terms 
``frame'' and ``receiver'' now exclude ``a removable end cap of an 
outer tube or modular piece.''
    The final rule does not adopt the definitional supplement of 
``split or modular frame or receiver,'' though a definition was added 
to define the term ``multi-piece frame or receiver'' and text was added 
to explain how and when such a frame or receiver must be marked. In 
this regard, the rebuttable presumption in the definition of ``frame or 
receiver'' was amended in the final rule to explain that the marked 
subpart(s) of a multi-piece frame or receiver must be presumed to be 
part of the frame or receiver of a weapon or device absent an ATF 
classification or other reliable evidence to the contrary.
    The final rule amends the supplement to the proposed definition of 
``frame or receiver'' entitled ``partially complete, disassembled, or 
inoperable frame or receiver'' by: (1) Replacing the term

[[Page 24728]]

``inoperable'' with the more accurate term ``nonfunctional''; (2) 
clarifying that this supplement also addresses frame or receiver parts 
kits; (3) explaining what it means for a frame or receiver to function 
as a frame or receiver;
    (4) removing the definition ``partially complete,'' and, instead, 
expressly excluding from the definition of ``frame or receiver'' 
forgings, castings, printings, extrusions, unmachined bodies, or 
similar articles that have not yet reached a stage of manufacture where 
they are clearly identifiable as an unfinished component part of a 
weapon (e.g., unformed blocks of metal, liquid polymers, and other raw 
materials); (5) clarifying the items that the Director may consider 
when classifying a partially complete, disassembled, or nonfunctional 
frame or receiver; and (6) providing detailed examples of what would 
and would not be a ``frame or receiver'' that may readily be completed, 
assembled, restored, or otherwise ``converted'' to a functional state.
    The final rule makes minor changes to the proposed supplement to 
the definition of ``frame or receiver'' entitled ``destroyed frame or 
receiver.'' For example, the final rule removes examples of specific 
ATF approved methods of destruction in the regulatory text in favor of 
general terminology. Additionally, the final rule clarifies that the 
term ``frame or receiver'' includes the specific component of a 
complete weapon or complete firearm muffler or silencer device, 
including variants thereof, determined (classified) by the Director to 
be defined as a firearm ``frame or receiver'' prior to publication of 
the final rule, except for determinations concluding that a partially 
complete, disassembled, or nonfunctional frame or receiver (including a 
weapon or frame or receiver parts kit) was not, or did not include, a 
firearm ``frame or receiver'' as previously defined. This 
``grandfather'' provision also includes nonexclusive examples and 
diagrams of previously classified weapons.

C. Definition of ``Readily''

    The final rule makes minor changes to the proposed definition of 
``readily'' in Parts 478 and 479 to make clear that it applies to any 
process, action, or physical state, and that the listed factors are 
only relevant to firearm classifications.

D. Definitions of ``Complete Weapon'' and ``Complete Muffler or 
Silencer Device''

    The final rule makes minor amendments to the proposed definitions 
of ``complete weapon'' and ``complete muffler or silencer device'' in 
Parts 478 and 479 by deleting ``as designed'' as it modified the phrase 
``necessary to function.'' This change was necessary to ensure that 
firearms are not designed to avoid marking time limits by eliminating a 
nonessential component in the manufacturing process.

E. Definition of ``Privately Made Firearm''

    The final rule makes minor changes to the proposed definition of 
``privately made firearm'' in part 478 to make it consistent with the 
changes to the definitions of ``frame or receiver'' and ``importer's or 
manufacturer's serial number,'' and for clarity regarding the exclusion 
for pre-October 22, 1968 manufactured firearms.

F. Definition of ``Importer's or Manufacturer's Serial Number''

    The final rule modifies the proposed definition of ``Importer's or 
manufacturer's serial number'' in part 478. The term means the serial 
number placed by a licensee on a firearm, including any full or 
abbreviated license number, any such identification on a privately made 
firearm, or a serial number issued by the Director. It also specifies 
that for purposes of 18 U.S.C. 922(k) and Sec.  478.34, the term shall 
include any associated licensee name, or licensee city or State placed 
on a firearm. These changes ensure that these markings are considered a 
part of the ``importer's or manufacturer's serial number'' because a 
firearm is difficult to trace without this information.

G. Definition of ``Gunsmith''

    This rule finalizes with clarifying changes the proposed definition 
of ``engaged in the business'' as it applies to a ``gunsmith'' in part 
478. Most significantly, the final rule makes clear that licensed 
dealer-gunsmiths are not required to be licensed as manufacturers if 
they only perform gunsmithing services on existing firearms for their 
customers, or for another licensee's customers, because the work is not 
being performed to create firearms for sale or distribution. These 
services may include customizing a customer's complete weapon by 
changing its appearance through painting, camouflaging, or engraving, 
applying protective coatings, or by replacing the original barrel, 
stock, or trigger mechanism with drop-in replacement parts.
    Licensed dealer-gunsmiths may also purchase complete weapons, make 
repairs (e.g., by replacing worn or broken parts), and resell them 
without being licensed as manufacturers. Likewise, under the final 
rule, licensed dealer-gunsmiths may make such repairs for other 
licensees who plan to resell them without being licensed as a 
manufacturer. They may also place marks of identification on PMFs they 
may purchase and sell, or under the direct supervision of another 
licensee in accordance with this rule. Persons performing these 
activities are distinguished from persons who engage in the business of 
completing or assembling parts or parts kits, applying coatings, or 
otherwise producing new or remanufactured firearms (frames or receivers 
or complete weapons) for sale or distribution. Such persons must be 
licensed as manufacturers.

H. Marking Requirements for Firearms

    The final rule makes a number of amendments to the proposed marking 
requirements in parts 478 and 479. In addition to minor changes to 
conform the marking requirements to the new definition of ``frame or 
receiver'' that describes a single component, the final rule amends the 
text to explain how and by when multi-piece frames or receivers are to 
be identified, and that an identified modular subpart thereof may only 
be removed and replaced under certain limited conditions. With regard 
to the size and depth of markings, a minor change was made to clarify 
that only the serial number and associated license number need be 
marked in a print size no smaller than \1/16\ inch. In the section 
addressing the meaning of marking terms, the final rule also defines 
the term ``identify'' to mean placement of identifying markings, 
clarifies that the term ``legibly'' means that the unique 
identification number within a serial number may include non-numeric 
characters, and also clarifies that the term ``conspicuous'' means that 
the markings must be capable of being easily seen with the naked eye.
    As to the time period for manufacturers to identify the firearms 
they produce, the term ``from completion of the active manufacturing 
process'' was not adopted in favor of the clearer statement ``the 
entire manufacturing process has ended.'' The exclusion from the time 
period for firearms ``actively awaiting materials'' was replaced with a 
rebuttable presumption that firearms awaiting materials, parts, or 
equipment repair to be completed are presumed, absent reliable evidence 
to the contrary, to be in the manufacturing process. Also, the time 
limits to mark firearms differentiate in the final rule between non-NFA 
complete weapons and frames

[[Page 24729]]

or receivers disposed of separately, which must be marked within seven 
days after completion of the manufacturing process, and NFA firearms 
and parts defined as firearms, which must be marked by close of the 
next business day. This provides a reasonable grace period in which to 
mark firearms manufactured and makes them consistent with their 
respective recordkeeping requirements under the GCA and NFA. The final 
rule does not adopt the proposed seven-day alternative for 
manufacturers to record acquisitions of non-NFA firearms if commercial 
records are maintained, as it was not necessary in light of the seven-
day grace period to mark non-NFA weapons. NFA weapons and parts must be 
marked and recorded by close of the next business day after 
manufacture. Furthermore, the final rule does not adopt the provision 
allowing licensees to obtain a variance for the period of time in which 
to mark their firearms because the grace periods being codified in the 
final rule are reasonable and well known to the industry.
    The final rule makes minor conforming amendments to the proposed 
requirement to mark PMFs. Additionally, unlike the proposed rule, the 
final rule allows licensed or unlicensed engravers to mark firearms on 
licensees' behalf (with the requesting licensee's information) 
provided: (1) The identification takes place under the direct 
supervision of the requesting licensee without the engraver taking the 
firearm into inventory; and (2) the markings otherwise meet the 
identification requirements. Also, the final rule text incorporates 
guidance from the NPRM's preamble that an acceptable method of 
identifying a PMF is by placing the serial number on a metal serial 
number plate permanently embedded into a polymer frame or receiver, or 
other method approved by the Director.
    With regard to the marking exceptions, the final rule expands the 
rules allowing licensees to adopt (and not mark) the serial number or 
other identifying markings under certain conditions. Specifically, in 
light of comments received, the final rule allows licensed 
manufacturers to adopt (and not mark) the serial number and other 
markings previously placed on a firearm that has not been sold, 
shipped, or otherwise disposed of to a person other than a licensee 
(i.e., newly manufactured firearms). This change would supersede ATF 
Ruling 2009-5, which requires ATF to be notified when marks are adopted 
as an alternative to marking. The final rule also provides more 
specificity than the proposed rule on how licensees who remanufacture 
or import firearms may adopt (and not mark) the markings on firearms 
that were sold, shipped, or disposed of to a nonlicensee. The final 
rule allows licensed manufacturers to adopt the serial number and other 
identifying markings previously placed on a firearm by another licensee 
provided the manufacturer is performing services as a gunsmith (as 
defined in Sec.  478.11) on existing firearms that are not for sale or 
distribution by a licensee. Further, the final rule allows licensees to 
adopt the unique identification number placed on a PMF by its 
unlicensed maker so long as the number is not duplicated on another 
firearm of the licensee, the number otherwise meets the identification 
requirements, and the licensee adds their abbreviated FFL number as a 
prefix to the existing identification number so that the firearm can be 
traced to the licensee who identified the firearm.
    The final rule also differs from the proposed rule in that it does 
not require firearm muffler or silencer parts that are transferred for 
further manufacture or repair to be ``actively'' in the manufacturing 
or repair process if those parts are being transferred for those 
purposes. In this regard, the definition of ``transfer'' in part 479 
has been finalized as proposed to exclude temporary conveyances solely 
for repair, identification, evaluation, research, testing, or 
calibration.
    The final rule retains the marking grandfathering provision, but 
revises the text to remove ``and configuration'' and defines ``new 
design'' to explain when a frame or receiver is eligible for this 
exception. Notably, the more limited final definition of ``new design'' 
only applies to changes in the design of the existing frame or receiver 
to the extent it has been functionally modified or altered, as 
distinguished from performing a cosmetic process that adds to or 
changes the decoration of the frame or receiver (e.g., painting or 
engraving), or by adding or replacing stocks, barrels, or accessories 
to the frame or receiver.
    With respect to the voluntary process for seeking an ATF 
classification of firearms, the final rule clarifies that a firearm 
sample submitted to ATF must include all accessories and attachments 
relevant to such classification, and that each request for 
classification of a partially complete, disassembled, or nonfunctional 
item or kit must contain any associated templates, jigs, molds, 
equipment, or tools that are made available by the seller or 
distributor of the item or kit to the purchaser or recipient of the 
item or kit, and any instructions, guides, or marketing materials if 
they will be made available by the seller or distributor with the item 
or kit. Further, submissions of armor piercing ammunition with a 
projectile or projectile core constructed entirely from one or a 
combination of tungsten steel alloys, steel, iron, brass, bronze, 
beryllium copper, or depleted uranium must include a list of known 
handguns in which the ammunition may be used. These changes will help 
to ensure that ATF can make a proper classification of firearms and 
armor piercing ammunition. The final rule also clarifies that ATF 
classifications of a specific component as a frame or receiver, as 
distinguished from other firearms determinations, may be considered 
applicable to or authoritative with respect to other firearms produced 
by the requestor that are similar so that a separate classification 
does not need to be submitted to know which portion of a similar weapon 
to mark.\146\
---------------------------------------------------------------------------

    \146\ ATF Rulings are different from private letter firearms 
classifications. ATF issues formal public rulings (as distinguished 
from ``private letter firearm classifications'' to individual 
industry members) to promote uniform understanding and application 
of the laws and regulations it administers. ATF Rulings apply the 
law and regulations to a specific set of facts, and apply 
retroactively unless otherwise indicated, whereas private letter 
firearm classifications are in response to a private inquiry for a 
determination regarding a specific item or parts kit by ATF. Rulings 
do not have the force and effect of ATF regulations, but may be 
cited and relied upon as precedents in the disposition of similar 
cases. See 27 CFR 70.701(d) (as in effect on January 23, 2003, and 
continued by 28 CFR 0.133(a)(2), (3)).
---------------------------------------------------------------------------

I. Recordkeeping

    Because firearms would not have more than one frame or receiver, 
the final rule does not finalize the proposed changes to Parts 447, 
478, and 479 to refer to in the plural form the manufacturer or 
importer name, country of manufacture, or serial number in required 
records. However, in the unlikely event there is more than one 
manufacturer or importer, country of manufacture, or serial number 
marked on a firearm, licensees must still record more than one name, 
country, or serial number in accordance with the existing regulatory 
requirements.\147\ In addition, the final rule substitutes 
``transaction number'' for ``serial number'' in part 478 with respect 
to the manner in which ATF Forms 4473 must be maintained to avoid 
confusion with the ``importer's or manufacturer's serial number'' 
placed

[[Page 24730]]

on a firearm. Further, the proposed recordkeeping requirement in part 
478 to record a ``serial number'' is amended to clarify that any 
license number either as a prefix, or if remanufactured or imported, 
separated by a semicolon, must be recorded in the serial number column 
for accurate tracing. The final rule also amends the proposed 
recordkeeping requirement for manufacturers in part 478 to make clear 
that production and acquisition records for non-NFA firearms 
manufactured or otherwise acquired must be recorded within seven days, 
not by close of the next business day as stated in the proposed rule, 
though NFA firearms must be recorded by close of the next business day 
unless there is a sufficient commercial record of acquisition, in which 
case the grace period to record would be extended until the seventh 
day.
---------------------------------------------------------------------------

    \147\ See 27 CFR 478.11 and 479.11 (``Words in the plural form 
shall include the singular, and vice versa . . . .''); FFL 
Newsletter, May 2012, at 5 (``If a firearm is marked with two 
manufacturer's names, or multiple manufacturer and importer names, 
FFLs should record each manufacturers' and importers' [sic] name in 
the A&D record.'').
---------------------------------------------------------------------------

    With regard to the licensee's acquisition of PMFs into inventory, 
the final rule clarifies in part 478 that the serial number need not be 
immediately recorded if the firearm is being identified by the 
licensee, or marked under the licensee's direct supervision, in 
accordance with Sec.  478.92(a)(2). Once marked, the acquisition entry 
must be updated. Further, unlike the proposed rule, the final rule 
expressly allows licensed dealer-gunsmiths, manufacturers, and 
importers to conduct same-day adjustments or repairs of unmarked PMFs 
without marking them so long as they do not accept them into inventory 
overnight and they are returned to the person from whom they were 
received. If, however, the licensee has possession of the firearm from 
one day to another or longer, the firearm must be recorded as an 
``acquisition,'' and then as a ``disposition'' in the A&D records upon 
return to the same customer. PMFs are thereby treated similarly to 
commercially produced firearms when same-day adjustments or repairs are 
conducted. Additionally, the final rule clarifies that a PMF must be 
recorded as an acquisition whenever it is marked for identification, 
including same-day or on-the-spot. The only exception is when another 
licensee places markings for, and under the direct supervision of, the 
licensee who recorded the acquisition. In that circumstance, the 
licensee marking the firearm need not enter the PMF as an acquisition 
or mark the PMF with their own information.
    The rule also finalizes with minor changes the proposed amendment 
to Sec.  479.103 that allows manufacturers to delay submission of an 
ATF Form 2, Notice of Firearms Manufactured or Imported, if firearm 
muffler or silencer parts are transferred between qualified licensees 
for further manufacture or to complete new devices that are registered 
upon completion of the device, or to repair existing, registered 
devices.

J. Record Retention

    This rule finalizes with few changes the proposed requirement in 
part 478 that all licensees retain their records until business or 
licensed activity is discontinued, either on paper or in an electronic 
alternate method approved by the Director, at the business or 
collection premises readily accessible for inspection. The final rule 
made changes to Sec.  478.50(a) to make clear that the warehouse for 
storage of firearms or ammunition inventory may also be used for the 
storage of records over 20 years of age. The warehouse may not be used 
to conduct other business activities, which would require a separate 
license and fee. 18 U.S.C. 923(a).

K. Effect on Prior ATF Rulings and Procedures

    ATF publishes formal rulings and procedures to promote uniform 
understanding and application of the laws and regulations it 
administers, and to provide uniform methods for performing operations 
in compliance with the requirements of the law and regulations. ATF 
Rulings represent ATF's guidance as to the application of the law and 
regulations to the entire state of facts involved, and apply 
retroactively unless otherwise indicated.\148\ Certain ATF Rulings and 
one ATF Procedure are impacted by this final rule, as follows:
---------------------------------------------------------------------------

    \148\ See 27 CFR 70.701(d)(2) (as in effect on January 23, 2003, 
and continued by 28 CFR 0.133(a)(2), (3)); Rulings, ATF (Oct. 20, 
2021), available at https://www.atf.gov/rules-and-regulations/rulings.
---------------------------------------------------------------------------

    The following rulings are hereby superseded: ATF Ruling 2009-1 
(Firearms Manufacturing Activities--Camouflaging or Engraving 
Firearms); ATF Ruling 2009-5 (Firearms Manufacturing Activities, 
Identification Markings of Firearms); ATF Ruling 2010-10 (Manufacturing 
Operations May be Performed by Licensed Gunsmiths Under Certain 
Conditions); ATF Ruling 2011-1 (Importers Consolidated Records); ATF 
Ruling 2012-1 (Time Period for Marking Firearms Manufactured); ATF 
Ruling 2013-3 (Adopting Identification of Firearms); and ATF Ruling 
2016-3 (Consolidation of Records Required for Manufacturers).
    The following rulings are hereby amplified: \149\ ATF Ruling 2002-6 
(Identification of Firearms, Armor Piercing Ammunition, and Large 
Capacity Ammunition Feeding Devices); ATF Ruling 2016-1 (Requirements 
to Keep Firearms Records Electronically) and ATF Ruling 2016-2 
(Electronic ATF Form 4473).
---------------------------------------------------------------------------

    \149\ The term ``amplified'' is used to describe a situation 
where no change is being made in a prior published position, but the 
prior position is being extended to apply to a variation of the fact 
situation set forth in the new ruling. Thus, if an earlier ruling 
held that a principle applied to (A), and the new ruling holds that 
the same principle also applies to (B), the earlier ruling is 
amplified. See Rulings, ATF (Oct. 20, 2021), available at https://www.atf.gov/rules-and-regulations/rulings.
---------------------------------------------------------------------------

    The following rulings and procedure are hereby clarified: \150\ 
Revenue Ruling 55-342 (FFLs Assembling Firearms from Component Parts); 
ATF Ruling 77-1 (Gunsmithing at Shooting Events); ATF Ruling 2009-2 
(Installation of Drop In Replacement Parts); ATF Ruling 2010-3 
(Identification of Maxim Side-Plate Receivers); ATF Ruling 2015-1 
(Manufacturing and Gunsmithing), and ATF Procedure 2020-1 
(Recordkeeping Procedure for Non-Over-the-Counter Firearm Sales By 
Licensees to Unlicensed In-State Residents That Are NICS Exempt).
---------------------------------------------------------------------------

    \150\ The term ``clarified'' is used to describe a situation 
where the language in a prior ruling is being made clear because the 
language has caused, or may cause, some confusion. It is not used 
where a position in a prior ruling is being changed. See Rulings, 
ATF (Oct. 20, 2021), available at https://www.atf.gov/rules-and-regulations/rulings.
---------------------------------------------------------------------------

L. Severability

    Based on the comments received in opposition to this rule, there is 
a reasonable possibility that this rule will be subject to litigation 
challenges. The Department has determined that this rule implements and 
is fully consistent with governing law. However, in the event any 
provision of this rule, an amendment or revision made by this rule, or 
the application of such provision or amendment or revision to any 
person or circumstance is held to be invalid or unenforceable by its 
terms, the remainder of this rule, the amendments or revisions made by 
this rule, and the application of the provisions of such rule to any 
person or circumstance shall not be affected and shall be construed so 
as to give them the maximum effect permitted by law.

VI. Statutory and Executive Order Review

A. Executive Orders 12866 and 13563

    Executive Orders 13563 (Improving Regulation and Regulatory Review) 
and 12866 (Regulatory Planning and Review) direct agencies to assess 
the costs and benefits of available regulatory alternatives and, if 
regulation is necessary, to select regulatory

[[Page 24731]]

approaches that maximize net benefits (including potential economic 
benefits, environmental benefits, public health and safety effects, 
distributive impacts, and equity). Executive Order 13563 emphasizes the 
importance of quantifying both costs and benefits, reducing costs, 
harmonizing rules, and promoting flexibility.
    The Office of Information and Regulatory Affairs at OMB has 
determined that while this final rule is not economically significant, 
it is a ``significant regulatory action'' under section 3(f)(4) of 
Executive Order 12866 because this final rule raises novel legal or 
policy issues arising out of legal mandates. Accordingly, the rule has 
been reviewed by OMB.
1. Need for Federal Regulatory Action
    In the NPRM, ATF stated that this rule would address externalities. 
Public comments stated that externalities deal with inefficiencies from 
market transactions, not actions dealing with the government. ATF 
concurs that this rule would not address externalities due to market 
inefficiencies; therefore, to avoid any confusion, ATF has removed 
language that suggested this rule would address a market inefficiency. 
Regardless, the publication of this final rule remains necessary to 
enforce the GCA and NFA.
    Agencies take regulatory action for various reasons. One of the 
reasons is to carry out Congress's policy decisions, as expressed in 
statutes. Here, this rulemaking aims to implement Congress's policy 
decision to require licensing, marking, recordkeeping, and background 
checks so that firearms can be traced if used in crime, and to prevent 
prohibited persons from acquiring them.
    This final rule is necessary is to address recent court cases, 
which have narrowly construed ATF's current regulatory definition of 
``frame or receiver.'' Such a narrow construction of the regulatory 
term creates the possibility that future courts may hold that the 
majority of regulated firearm frames or receivers do not meet the 
existing definition. Furthermore, administrative inspections, criminal 
investigations, and prosecutions are hindered when PMFs, which are 
untraceable, are accepted into and disposed of from a licensee's 
inventory, and when firearms records are destroyed after 20 years 
despite the need of these records to combat criminal activities.
    This final rule updates the existing definition of ``frame or 
receiver'' to account for technological advances in the industry and 
ensure that firearms continue to remain under the regulatory regime as 
intended by the enactment of the GCA, including accounting for 
manufacturing of firearm parts kits and PMFs made from those kits. The 
narrow interpretation of what constitutes a ``frame or receiver'' by 
some courts may potentially allow persons to avoid: (1) Having to 
obtain a license to engage in the business of manufacturing or 
importing frames or receivers; (2) identifying frames or receivers with 
a serial number and other traceable markings; (3) maintaining records 
of frames or receivers produced or imported through which they can be 
traced; and (4) running NICS checks on potential transferees to 
determine if they are legally prohibited from receiving or possessing 
firearms when they acquire frames or receivers. In turn, this would 
allow otherwise prohibited persons to acquire frames or receivers that 
can quickly be assembled into semiautomatic weapons easily and without 
a background check.
    If no portion of split or multi-piece frames or receivers were 
subject to any existing regulations, such as marking, recordkeeping, or 
background checks, law enforcement's ability to trace semiautomatic 
firearms used in the commission of a crime would be severely impeded. 
This final rule makes consistent the marking requirements for firearms 
to facilitate tracing in the event a firearm is used in the commission 
of a crime. In order to accommodate the additional PMF marking 
requirements, this final rule clarifies and expands the definition of 
``gunsmithing.'' In addition, this final rule requires FFLs to retain 
all firearms records, either in hard copy or electronically, until the 
Federal firearms licensed business or licensed activity is 
discontinued. For more specific details regarding the need for 
regulation, please refer to the specific chapters of the standalone RIA 
pertaining to each provision of this final rule.
2. Summary of Affected Population, Costs, and Benefits
    Table 2 provides a summary of the affected population and 
anticipated costs and benefits of promulgating this rule.

      Table 2--Summary of Affected Population, Costs, and Benefits
------------------------------------------------------------------------
                Category                            Final rule
------------------------------------------------------------------------
Applicability..........................  <bullet> Definition of Frame or
                                          Receiver.
                                         <bullet> Updates Marking
                                          Requirements.
                                         <bullet> New Gunsmith
                                          Definition.
                                         <bullet> Updates Record
                                          Retention.
Affected Population....................  <bullet> 113,204 FFLs.
                                         <bullet> 19,449 FFL Type 07
                                          manufacturers.
                                         <bullet> 43 Non-FFL
                                          manufacturers.
                                         <bullet> 114,001 FFL dealers,
                                          pawnbrokers, and collectors.
                                         <bullet> 24 Non-FFL dealers.
                                         <bullet> Approximately 1
                                          million individual owners.
Total Costs to Industry, Public, and     $14.3 million annualized.
 Government (7 percent Discount Rate).
Benefits (7 percent Discount Rate).....  Not estimated.
Benefits (Qualitative).................  <bullet> Provides clarity to
                                          courts on what constitutes a
                                          firearm frame or receiver.
                                         <bullet> Adapts to new
                                          technology/terminology.
                                         <bullet> Makes consistent
                                          marking requirements.
                                         <bullet> Eases certain marking
                                          requirements.
                                         <bullet> Increases tracing of
                                          crime scene firearms to
                                          prosecute criminals.
                                         <bullet> Restricts felons and
                                          other prohibited persons from
                                          acquiring PMFs.
------------------------------------------------------------------------


[[Page 24732]]

3. Changes From the NPRM to FR
    Section V of this preamble describes the regulatory text of the 
final rule and the changes from the proposed rule. The following is a 
list of substantive changes:
(1) Definition of ``Frame or Receiver''
    <bullet> The final rule describes one part of a projectile weapon 
that will be either the ``frame'' or ``receiver'' with examples and 
pictures still provided.
    <bullet> The final rule defines ``variant'' and more clearly 
grandfathers existing classifications (e.g., AR-15/M-16 variants).
    <bullet> The final rule clarifies the one part of a firearm muffler 
or silencer device that is the frame or receiver and addresses how 
modular silencers are marked.
    <bullet> The final rule defines ``multi-piece frame or receiver'' 
and specifically addresses how such parts must be marked.
    <bullet> The final rule clarifies the supplement titled ``partially 
complete, disassembled, or inoperable [now `nonfunctional'] frame or 
receiver'' and provides examples.
    <bullet> The final rule clarifies the materials that need to be 
submitted when voluntarily seeking a firearm or armor piercing 
ammunition classification from ATF.
(2) PMFs
    <bullet> The final rule requires FFLs to mark and record PMFs only 
when they are received or otherwise acquired into inventory, but allows 
PMFs to be adjusted or repaired and returned on the same day without 
marking.
    <bullet> The final rule allows FFLs to directly supervise a 
nonlicensee who may mark the PMF for the licensee in accordance with 
the regulations.
    <bullet> The final rule clarifies who is required to be licensed as 
a gunsmith eligible to mark PMFs without a manufacturer's license.
(3) Marking
    <bullet> The final rule defines ``new design'' to inform 
manufacturers as to when they are required to mark firearms they 
manufacture in accordance with the new marking requirements (i.e., 
either FFL name, city, and State; or FFL name and abbreviated FFL 
number placed on the frame or receiver).
    <bullet> The final rule expands adoption of marking allowances and 
addresses an additional three circumstances where markings can be 
adopted. These include newly manufactured firearms, manufacturers 
performing gunsmithing services, and PMFs marked by nonlicensees.
    <bullet> The final rule provides that an acceptable way for PMFs to 
be marked is by placing the serial number on a metal plate that is 
permanently embedded into a polymer frame or receiver, or other method 
approved by the Director.
(4) Recordkeeping
    <bullet> The final rule clarifies that manufacturers have seven 
days to enter non-NFA firearms into their records, and by close of the 
next business day for manufactured NFA firearms.
    <bullet> The final rule clarifies that licensed dealers (including 
gunsmiths), manufacturers, and importers may conduct adjustments or 
repairs of all firearms without recording them as acquisitions or 
dispositions provided they are returned to the person from whom they 
were received on the same day.
    <bullet> The final rule clarifies that PMFs must be recorded as an 
acquisition when a licensee places marks of identification, and as a 
disposition upon return (unless the licensee is marking under the 
direct supervision of another licensee who recorded the acquisition).
(5) Record Retention
    <bullet> The final rule clarifies that FFLs are required to 
maintain their records until licensed activity is discontinued.

B. Executive Order 13132

    This regulation will not have substantial direct effects on the 
States, the relationship between the Federal Government and the States, 
or the distribution of power and responsibilities among the various 
levels of government. Therefore, in accordance with section 6 of 
Executive Order 13132 (Federalism), the Attorney General has determined 
that this regulation does not have sufficient federalism implications 
to warrant the preparation of a federalism summary impact statement.

C. Executive Order 12988

    This regulation meets the applicable standards set forth in 
sections 3(a) and 3(b)(2) of Executive Order 12988 (Civil Justice 
Reform).

D. Regulatory Flexibility Act (``RFA'')

    The RFA establishes ``as a principle of regulatory issuance that 
agencies shall endeavor, consistent with the objectives of the rule and 
of applicable statutes, to fit regulatory and informational 
requirements to the scale of the businesses, organizations, and 
governmental jurisdictions subject to regulation. To achieve this 
principle, agencies are required to solicit and consider flexible 
regulatory proposals and to explain the rationale for their actions to 
assure that such proposals are given serious consideration.'' Public 
Law 96-354, sec. 2(b), 94 Stat. 1164, 1165 (1980).
    Under the RFA, the agency is required to consider if this rule will 
have a significant economic impact on a substantial number of small 
entities. Agencies must perform a review to determine whether a rule 
will have such an impact. If the agency determines that it will, the 
agency must prepare a regulatory flexibility analysis as described in 
the RFA.
    Under the RFA (5 U.S.C. 604(a)), the final regulatory flexibility 
analysis (``FRFA'') must contain:
    <bullet> A statement of the need for, and objectives of, the rule;
    <bullet> a statement of the significant issues raised by the public 
comments in response to the initial regulatory flexibility analysis, a 
statement of the assessment of the agency of such issues, and a 
statement of any changes made in the proposed rule as a result of such 
comments;
    <bullet> the response of the agency to any comments filed by the 
Chief Counsel for Advocacy of the Small Business Administration in 
response to the proposed rule, and a detailed statement of any change 
made to the proposed rule in the final rule as a result of the 
comments;
    <bullet> a description of and an estimate of the number of small 
entities to which the rule will apply or an explanation of why no such 
estimate is available;
    <bullet> a description of the projected reporting, recordkeeping, 
and other compliance requirements of the rule, including an estimate of 
the classes of small entities which will be subject to the requirement 
and the type of professional skills necessary for preparation of the 
report or record; and
    <bullet> a description of the steps the agency has taken to 
minimize the significant economic impact on small entities consistent 
with the stated objectives of applicable statutes, including a 
statement of the factual, policy, and legal reasons for selecting the 
alternative adopted in the final rule and why each one of the other 
significant alternatives to the rule considered by the agency that 
affect the impact on small entities was rejected.
    ATF estimates that this final rule will have a significant impact 
on a substantial number of small businesses. Therefore, ATF has 
prepared an FRFA. For more details regarding the impacts to small 
businesses, please refer to the standalone RIA located on the docket.

[[Page 24733]]

E. Small Business Regulatory Enforcement Fairness Act of 1996

    This rule is likely to have a significant economic impact on a 
substantial number of small entities under the Small Business 
Regulatory Enforcement Fairness Act of 1996 (``SBREFA''), 5 U.S.C. 601 
et seq. Accordingly, the Department prepared an initial regulatory 
flexibility analysis (IRFA) for the proposed rule and prepared an FRFA 
for the final rule. 5 U.S.C. 603-04. Furthermore, a small business 
compliance guide will be published as required by SBREFA.

F. Congressional Review Act

    Pursuant to the Congressional Review Act, 5 U.S.C. 801 et seq., 
OMB's Office of Information and Regulatory Affairs has determined this 
rule is not a ``major rule,'' as defined by 5 U.S.C. 804(2). This rule 
will not result in an annual effect on the economy of $100 million or 
more; a major increase in costs or prices; or significant adverse 
effects on competition, employment, investment, productivity, 
innovation, or on the ability of United States-based enterprises to 
compete with foreign-based enterprises in domestic and export markets. 
While there may be impacts on employment, investment, productivity, or 
innovation, these impacts will not have a significant impact on the 
overall economy.

G. Unfunded Mandates Reform Act of 1995

    This rule will not result in the expenditure by State, local, and 
Tribal governments, in the aggregate, or by the private sector, of $100 
million or more in any one year (adjusted for inflation), and it will 
not significantly or uniquely affect small governments. Therefore, no 
actions were deemed necessary under the provisions of the Unfunded 
Mandates Reform Act of 1995, Public Law 104-4, 109 Stat. 48.

H. Paperwork Reduction Act of 1995

    This rule would call for collections of information under the 
Paperwork Reduction Act of 1995, 44 U.S.C. 3501 et seq. As defined in 5 
CFR 1320.3(c), ``collection of information'' comprises reporting, 
recordkeeping, monitoring, posting, labeling, and other similar 
actions. The title and description of the information collection, a 
description of those who must collect the information, and an estimate 
of the total annual burden follow. The estimate covers the time for 
reviewing instructions, searching existing sources of data, gathering 
and maintaining the data needed, and completing and reviewing the 
collection.
    Under the provisions of this proposed rule, there is a one-time 
increase in paperwork burdens of identification markings placed on 
firearms as well as additional transaction records. This requirement 
would be added to an existing approved collection covered by OMB 
control numbers 1140-0018, 1140-0032, 1140-0050, and 1140-0067.
    Title: Application for a Federal Firearms License.
    OMB Control Number: OMB 1140-0018.
    Proposed Use of Information: This collection of information is 
necessary to ensure that anyone who wishes to be licensed as required 
by 18 U.S.C. 923 meets the requirements to obtain the desired license.
    Description and Number of Respondents: Currently there are 13,000 
applications for a license. This final rule will effect a one-time 
increase in one respondent.
    Frequency of Response: There will be a recurring response for all 
currently existing FFLs. This final rule would affect a one-time number 
of one response (13,001 respondents * 1 response).
    Burden of Response: This includes recurring time burden of one 
hour. ATF anticipates a one-time hourly burden of one hour per 
respondent.
    Estimate of Total Annual Burden: The current burden listed in this 
collection of information is 13,000 hours. The new burden, as a result 
of this final rule, is a one-time hourly burden of 13,001 (13,001 
respondents * 1 time response * 1 hourly burden per respondent).

    Title: Records of Acquisition and Disposition, Type 01/02 Dealer of 
Firearms.
    OMB Control Number: OMB 1140-0032.
    Proposed Use of Information: The recordkeeping requirements as 
contemplated by 18 U.S.C. 923, as amended, are for the primary purpose 
of facilitating ATF's authority to inquire into the disposition of any 
firearm in the course of a criminal investigation, and conduct 
compliance inspections. Because the regulations require uniform formats 
for recordkeeping, the records serve a major secondary purpose: 
Granting ATF Officers the ability to examine records for firearms 
traces or compliance inspections, per 18 U.S.C. 923(g)(1)(B), (C).
    Description and Number of Respondents: Currently there are 60,790 
respondents. The final rule will not increase the number of 
respondents, though we anticipate that 116 current respondents will 
have firearm parts kits and will therefore have an additional burden 
under this final rule.
    Frequency of Response: There will be a recurring response for all 
currently existing Type 01 and Type 02 FFLs. The frequency of response 
will be dependent on the inventory and sales of FFLs.
    Burden of Response: The burden of response was estimated at 60,790 
hours for inspections. No burden was attributed to entries in records.
    Estimate of Total Annual Burden: The current burden listed in this 
collection of information is 60,790 hours. The new burden, as a result 
of the final rule, is an hourly burden of 116 hours (116 respondents * 
10 items * 2 responses * 0.05 hourly burden per entry).

    Title: Identification Markings Placed on Firearms.
    OMB Control Number: OMB 1140-0050.
    Proposed Use of Information: ATF would use this information in 
fighting crime by facilitating the tracing of firearms used in criminal 
activities. The systematic tracing of firearms from the manufacturer or 
U.S. importer to the retail purchaser also enables law enforcement 
agencies to identify suspects involved in criminal violations, 
determine if a firearm is stolen, and provide other information 
relevant to a criminal investigation.
    Description and Number of Respondents: Currently there are 12,252 
licensed manufacturers of firearms and 1,343 licensed importers. Of the 
potential number of licensed dealers and licensed pawnbrokers, ATF 
estimates that those directly affected would be a one-time surge of 42 
licensed dealers and 74 licensed pawnbrokers. The final rule would 
affect a one-time surge of 116 respondents.
    Frequency of Response: There will be a recurring response for all 
currently existing 13,595 licensed manufacturers and licensed 
importers. The final rule would affect a one-time number of 1,160 
responses (116 one-time respondents *10 responses). There will be an 
annual increase of 101,136 responses (42 respondents * 2,408 
responses).
    Burden of Response: This includes a recurring time burden of one 
minute.
    Estimate of Total Annual Burden: The current burden listed in this 
collection of information is 85,630 hours. The new burden, as a result 
of the final rule, is a one-time hourly burden of 19 (116 one-time 
respondents * 10 responses * 0.016667 hourly burden per respondent). 
The new recurring burden as a result of the final rule is 1,686 hours 
(42 existing respondents * 2,408 responses * 0.016667 hourly burden).

    Title: Licensed Firearms Manufacturers Records of Production, 
Disposition, and Supporting Data.

[[Page 24734]]

    OMB Control Number: OMB 1140-0067.
    Proposed Use of Information: ATF would use this information for 
criminal investigation or regulatory compliance with the Gun Control 
Act of 1968. The Attorney General may inspect or examine the inventory 
and records of a licensed importer, licensed manufacturer, or licensed 
dealer, without such reasonable cause or warrant, and during the course 
of a criminal investigation of a person or persons other than the 
licensee, in order to ensure compliance with the recordkeeping 
requirements of 18 U.S.C. 923(g)(1)(A). The Attorney General may also 
inspect or examine any records relating to firearms involved in a 
criminal investigation that are traced to the licensee, or firearms 
that may have been disposed of during the course of a bona fide 
criminal investigation. 18 U.S.C. 923(g)(1)(B), (C).
    Description and Number of Respondents: The current number of 
respondents is 9,056 firearm manufacturers. The final rule will affect 
a subset of existing respondents (42 respondents).
    Frequency of Response: There will be a recurring response for all 
9,056 licensed manufacturers. The final rule will effect an increase in 
records of 202,272 responses.
    Burden of Response: This includes a recurring time burden of 1 
minute. The burden resulting from the final rule is 3,371 hours 
annually.
    Estimate of Total Annual Burden: The current burden listed in this 
collection of information is 201,205 hours. The new burden, as a result 
of the final rule, is 3,371 hours (42 respondents * 0.016667 hours * 
4,816 responses).

Disclosure

    Copies of the final rule, proposed rule, and comments received in 
response to the proposed rule will be available for public inspection 
through the Federal eRulemaking portal, http://regulations.gov, or by 
appointment during normal business hours at: ATF Reading Room, Room 1E-
063, 99 New York Ave. NE, Washington, DC 20226; telephone: (202) 648-
8740.

List of Subjects

27 CFR Part 447

    Administrative practice and procedure, Arms and munitions, 
Chemicals, Customs duties and inspection, Imports, Penalties, Reporting 
and recordkeeping requirements, Scientific equipment, Seizures and 
forfeitures.

27 CFR Part 478

    Administrative practice and procedure, Arms and munitions, Exports, 
Freight, Imports, Intergovernmental relations, Law enforcement 
officers, Military personnel, Penalties, Reporting and recordkeeping 
requirements, Research, Seizures and forfeitures, Transportation.

27 CFR Part 479

    Administrative practice and procedure, Arms and munitions, Excise 
taxes, Exports, Imports, Military personnel, Penalties, Reporting and 
recordkeeping requirements, Seizures and forfeitures, Transportation.

Authority and Issuance

    Accordingly, for the reasons discussed in the preamble, 27 CFR 
parts 447, 478, and 479 are amended as follows:

PART 447--IMPORTATION OF ARMS, AMMUNITION AND IMPLEMENTS OF WAR

0
1. The authority citation for 27 CFR part 447 continues to read as 
follows:

    Authority: 22 U.S.C. 2778; E.O. 13637, 78 FR 16129 (Mar. 8, 
2013).


0
2. Amend Sec.  447.11 by adding, in alphabetical order, definitions for 
``Frame or receiver'', and ``Privately made firearm'', to read as 
follows:


Sec.  447.11   Meaning of terms.

* * * * *
    Frame or receiver. The term ``frame or receiver'' shall have the 
same meaning as in 27 CFR 478.12.
* * * * *
    Privately made firearm. The term ``privately made firearm'' shall 
have the same meaning as in 27 CFR 478.11.
* * * * *


Sec.  447.42   [Amended]

0
3. In Sec.  447.42 amend paragraph (a)(1)(iv)(A) by adding the phrase 
``of the defense article, or ``privately made firearm'' (if a firearm 
privately made in the United States)'' after the word ``manufacturer''.


Sec.  447.45   [Amended]

0
4. In Sec.  447.45 amend paragraph (a)(2)(ii) by adding the phrase ``, 
or ``privately made firearm'' (if a firearm privately made in the 
United States)'' after ``defense article''.

PART 478--COMMERCE IN FIREARMS AND AMMUNITION

0
5. The authority citation for 27 CFR part 478 continues to read as 
follows:

    Authority: 5 U.S.C. 552(a); 18 U.S.C. 847, 921-931; 44 U.S.C. 
3504(h).


0
6. Amend Sec.  478.11 by:
0
a. In the introductory text, removing the word ``section'' and adding, 
in its place, the word ``subpart'';
0
b. Adding, in alphabetical order, definitions for ``Complete muffler or 
silencer device'' and ``Complete weapon'';
0
c. In the definition of ``Engaged in the business'' revising paragraph 
(d);
0
d. Revising the definition of ``Firearm'';
0
d. Removing the definition of ``Firearm frame or receiver'';
0
e. Adding, in alphabetical order, definitions for ``Frame or 
receiver'', ``Importer's or manufacturer's serial number'', ``Privately 
made firearm (PMF)'', and ``Readily''; and
    The revisions and additions read as follows:


Sec.  478.11   Meaning of terms.

* * * * *
    Complete muffler or silencer device. A firearm muffler or firearm 
silencer that contains all component parts necessary to function, 
whether or not assembled or operable.
    Complete weapon. A firearm other than a firearm muffler or firearm 
silencer that contains all component parts necessary to function, 
whether or not assembled or operable.
* * * * *
    Engaged in the business-- * * *
    (d) Gunsmith. A person who, as a service performed on existing 
firearms not for sale or distribution, devotes time, attention, and 
labor to repairing or customizing firearms, making or fitting special 
barrels, stocks, or trigger mechanisms to firearms, or placing marks of 
identification on privately made firearms in accordance with this part, 
as a regular course of trade or business with the principal objective 
of livelihood and profit, but such term shall not include a person who 
occasionally repairs or customizes firearms (including identification), 
or occasionally makes or fits special barrels, stocks, or trigger 
mechanisms to firearms. In the case of firearms for purposes of sale or 
distribution, such term shall include a person who performs repairs 
(e.g., by replacing worn or broken parts) on complete weapons, or 
places marks of identification on privately made firearms, but shall 
not include a person who manufactures firearms (i.e., frames or 
receivers or complete weapons) by completion, assembly, or applying 
coatings, or otherwise making them suitable for use, requiring a 
license as a manufacturer;
* * * * *

[[Page 24735]]

    Firearm. Any weapon, including a starter gun, which will or is 
designed to or may readily be converted to expel a projectile by the 
action of an explosive; the frame or receiver of any such weapon; any 
firearm muffler or firearm silencer; or any destructive device; but the 
term shall not include an antique firearm. In the case of a licensed 
collector, the term shall mean only curios and relics. The term shall 
include a weapon parts kit that is designed to or may readily be 
completed, assembled, restored, or otherwise converted to expel a 
projectile by the action of an explosive. The term shall not include a 
weapon, including a weapon parts kit, in which the frame or receiver of 
such weapon is destroyed as described in the definition ``frame or 
receiver''.
* * * * *
    Frame or receiver. The term ``frame or receiver'' shall have the 
same meaning as in Sec.  478.12.
* * * * *
    Importer's or manufacturer's serial number. The serial number 
placed by a licensee on a firearm, including any full or abbreviated 
license number, any such identification on a privately made firearm, or 
a serial number issued by the Director. For purposes of 18 U.S.C. 
922(k) and Sec.  478.34, the term shall include any associated licensee 
name, or licensee city or State placed on a firearm.
* * * * *
    Privately made firearm (PMF). A firearm, including a frame or 
receiver, completed, assembled, or otherwise produced by a person other 
than a licensed manufacturer, and without a serial number placed by a 
licensed manufacturer at the time the firearm was produced. The term 
shall not include a firearm identified and registered in the National 
Firearms Registration and Transfer Record pursuant to chapter 53, title 
26, United States Code, or any firearm manufactured or made before 
October 22, 1968 (unless remanufactured after that date).
* * * * *
    Readily. A process, action, or physical state that is fairly or 
reasonably efficient, quick, and easy, but not necessarily the most 
efficient, speediest, or easiest process, action, or physical state. 
With respect to the classification of firearms, factors relevant in 
making this determination include the following:
    (1) Time, i.e., how long it takes to finish the process;
    (2) Ease, i.e., how difficult it is to do so;
    (3) Expertise, i.e., what knowledge and skills are required;
    (4) Equipment, i.e., what tools are required;
    (5) Parts availability, i.e., whether additional parts are 
required, and how easily they can be obtained;
    (6) Expense, i.e., how much it costs;
    (7) Scope, i.e., the extent to which the subject of the process 
must be changed to finish it; and
    (8) Feasibility, i.e., whether the process would damage or destroy 
the subject of the process, or cause it to malfunction.
* * * * *

0
7. Add Sec.  478.12 to subpart B to read as follows:


Sec.  478.12   Definition of Frame or Receiver.

    (a) Except as otherwise provided in this section, the term ``frame 
or receiver'' means the following--
    (1) The term ``frame'' means the part of a handgun, or variants 
thereof, that provides housing or a structure for the primary energized 
component designed to hold back the hammer, striker, bolt, or similar 
component prior to initiation of the firing sequence (i.e., sear or 
equivalent), even if pins or other attachments are required to connect 
such component to the housing or structure.
    (2) The term ``receiver'' means the part of a rifle, shotgun, or 
projectile weapon other than a handgun, or variants thereof, that 
provides housing or a structure for the primary component designed to 
block or seal the breech prior to initiation of the firing sequence 
(i.e., bolt, breechblock, or equivalent), even if pins or other 
attachments are required to connect such component to the housing or 
structure.
    (3) The terms ``variant'' and ``variants thereof'' mean a weapon 
utilizing a similar frame or receiver design irrespective of new or 
different model designations or configurations, characteristics, 
features, components, accessories, or attachments. For example, an AK-
type firearm with a short stock and a pistol grip is a pistol variant 
of an AK-type rifle, an AR-type firearm with a short stock and a pistol 
grip is a pistol variant of an AR-type rifle, and a revolving cylinder 
shotgun is a shotgun variant of a revolver.
    (4) The following are nonexclusive examples that illustrate the 
above definitions:
    (i) Hinged or single framed revolvers: The frame is the part of the 
revolver that provides a structure designed to hold the sear.
[GRAPHIC] [TIFF OMITTED] TR26AP22.001

    (ii) Colt 1911, Beretta/Browning/FN Herstal/Heckler & Koch/Ruger/
Sig Sauer/Smith & Wesson/Taurus hammer-fired semiautomatic pistols: The 
frame is the lower portion of the pistol, or grip, that provides 
housing for the sear.

[[Page 24736]]

[GRAPHIC] [TIFF OMITTED] TR26AP22.002

    (iii) Glock variant striker-fired semiautomatic pistols: The frame 
is the lower portion of the pistol, or grip, that provides housing for 
the sear.
[GRAPHIC] [TIFF OMITTED] TR26AP22.003

    (iv) Sig Sauer P250/P320 variant semiautomatic pistols: The frame 
is the internal removable chassis of the pistol that provides housing 
for the energized component (i.e., sear or equivalent).
[GRAPHIC] [TIFF OMITTED] TR26AP22.004

    (v) Bolt action rifles: The receiver is the part of the rifle that 
provides a structure for the bolt.

[[Page 24737]]

[GRAPHIC] [TIFF OMITTED] TR26AP22.005

    (vi) Break action, lever action, or pump action rifles and 
shotguns: The receiver is the part of the rifle or shotgun that 
provides housing for the bolt, breechblock, or equivalent.
[GRAPHIC] [TIFF OMITTED] TR26AP22.006

    (vii) AK variant firearms: The receiver is the part of the weapon 
that provides housing for the bolt.
[GRAPHIC] [TIFF OMITTED] TR26AP22.007

    (viii) Steyr AUG variant firearms: The receiver is the central part 
of the weapon that provides housing for the bolt.

[[Page 24738]]

[GRAPHIC] [TIFF OMITTED] TR26AP22.008

    (ix) Thompson machineguns and semiautomatic variants, and L1A1, FN 
FAL, FN FNC, MP38, MP40, and SIG 550 firearms, and HK machineguns and 
semiautomatic variants: The receiver is the upper part of the weapon 
that provides housing for the bolt.
[GRAPHIC] [TIFF OMITTED] TR26AP22.009

    (x) Sten, Sterling, and Kel-Tec SUB-2000 firearms: The receiver is 
the central part of the weapon, or tube, that provides housing for the 
bolt.
[GRAPHIC] [TIFF OMITTED] TR26AP22.010


[[Page 24739]]


    (b) Firearm muffler or silencer frame or receiver. The terms 
``frame'' and ``receiver'' shall mean, in the case of a firearm muffler 
or firearm silencer, the part of the firearm, such as an outer tube or 
modular piece, that provides housing or a structure for the primary 
internal component designed to reduce the sound of a projectile (i.e., 
baffles, baffling material, expansion chamber, or equivalent). In the 
case of a modular firearm muffler or firearm silencer device with more 
than one such part, the terms shall mean the principal housing attached 
to the weapon that expels a projectile, even if an adapter or other 
attachments are required to connect the part to the weapon. The terms 
shall not include a removable end cap of an outer tube or modular 
piece.
    (c) Partially complete, disassembled, or nonfunctional frame or 
receiver. The terms ``frame'' and ``receiver'' shall include a 
partially complete, disassembled, or nonfunctional frame or receiver, 
including a frame or receiver parts kit, that is designed to or may 
readily be completed, assembled, restored, or otherwise converted to 
function as a frame or receiver, i.e., to house or provide a structure 
for the primary energized component of a handgun, breech blocking or 
sealing component of a projectile weapon other than a handgun, or 
internal sound reduction component of a firearm muffler or firearm 
silencer, as the case may be. The terms shall not include a forging, 
casting, printing, extrusion, unmachined body, or similar article that 
has not yet reached a stage of manufacture where it is clearly 
identifiable as an unfinished component part of a weapon (e.g., 
unformed block of metal, liquid polymer, or other raw material). When 
issuing a classification, the Director may consider any associated 
templates, jigs, molds, equipment, tools, instructions, guides, or 
marketing materials that are sold, distributed, or possessed with the 
item or kit, or otherwise made available by the seller or distributor 
of the item or kit to the purchaser or recipient of the item or kit. 
The following are nonexclusive examples that illustrate the 
definitions:
    Example 1 to paragraph (c)--Frame or receiver: A frame or receiver 
parts kit containing a partially complete or disassembled billet or 
blank of a frame or receiver that is sold, distributed, or possessed 
with a compatible jig or template is a frame or receiver, as a person 
with online instructions and common hand tools may readily complete or 
assemble the frame or receiver parts to function as a frame or 
receiver.
    Example 2 to paragraph (c)--Frame or receiver: A partially complete 
billet or blank of a frame or receiver with one or more template holes 
drilled or indexed in the correct location is a frame or receiver, as a 
person with common hand tools may readily complete the billet or blank 
to function as a frame or receiver.
    Example 3 to paragraph (c)--Frame or receiver: A complete frame or 
receiver of a weapon that has been disassembled, damaged, split, or cut 
into pieces, but not destroyed in accordance with paragraph (e), is a 
frame or receiver.
    Example 4 to paragraph (c)--Not a receiver: A billet or blank of an 
AR-15 variant receiver without critical interior areas having been 
indexed, machined, or formed that is not sold, distributed, or 
possessed with instructions, jigs, templates, equipment, or tools such 
that it may readily be completed is not a receiver.
    Example 5 to paragraph (c)--Not a receiver: A flat blank of an AK 
variant receiver without laser cuts or indexing that is not sold, 
distributed, or possessed with instructions, jigs, templates, 
equipment, or tools is not a receiver, as a person cannot readily fold 
the flat to provide housing or a structure for the primary component 
designed to block or seal the breech prior to initiation of the firing 
sequence.
    (d) Multi-piece frame or receiver. The term ``multi-piece frame or 
receiver'' shall mean a frame or receiver that may be disassembled into 
multiple modular subparts, i.e., standardized units that may be 
replaced or exchanged. The term shall not include the internal frame of 
a pistol that is a complete removable chassis that provides housing for 
the energized component, unless the chassis itself may be disassembled. 
The modular subpart(s) identified in accordance with Sec.  478.92 with 
an importer's or manufacturer's serial number shall be presumed, absent 
an official determination by the Director or other reliable evidence to 
the contrary, to be part of the frame or receiver of a weapon or 
device.
    (e) Destroyed frame or receiver. The terms ``frame'' and 
``receiver'' shall not include a frame or receiver that is destroyed. 
For purposes of these definitions, the term ``destroyed'' means that 
the frame or receiver has been permanently altered such that it may not 
readily be completed, assembled, restored, or otherwise converted to 
function as a frame or receiver. Acceptable methods of destruction 
include completely melting, crushing, or shredding the frame or 
receiver, or other method approved by the Director.
    (f)(1) Frame or receiver classifications based on which part of the 
weapon was classified as such before April 26, 2022. Except as provided 
in paragraph (f)(2) of this section, the terms ``frame'' and 
``receiver'' shall include the specific part of a complete weapon, 
including variants thereof, determined (classified) by the Director to 
be defined as a firearm frame or receiver prior to April 26, 2022. Any 
such part that is identified with an importer's or manufacturer's 
serial number shall be presumed, absent an official determination by 
the Director or other reliable evidence to the contrary, to be the 
frame or receiver of the weapon. The following is a nonexclusive list 
of such weapons and the specific part determined by the Director to be 
the firearm frame or receiver as they existed on that date:
    (i) AR-15/M-16 variant firearms: The receiver is the lower part of 
the weapon that provides housing for the trigger mechanism and hammer 
(i.e., lower receiver).

[[Page 24740]]

[GRAPHIC] [TIFF OMITTED] TR26AP22.011

    (ii) Ruger Mark IV pistol: The frame is the upper part of the 
weapon that provides housing for the bolt or breechblock.
[GRAPHIC] [TIFF OMITTED] TR26AP22.012

    (iii) Benelli 121 M1 Shotgun: The receiver is the lower part of the 
weapon that provides housing for the trigger mechanism.
[GRAPHIC] [TIFF OMITTED] TR26AP22.013

    (iv) Vickers/Maxim, Browning 1919, M2, and box-type machineguns and 
semiautomatic variants: The receiver is the side plate of the weapon 
that is designed to hold the charging handle.

[[Page 24741]]

[GRAPHIC] [TIFF OMITTED] TR26AP22.014

    (2) Frame or receiver classifications of partially complete, 
disassembled, or nonfunctional frames or receivers before April 26, 
2022. Prior determinations by the Director that a partially complete, 
disassembled, or nonfunctional frame or receiver, including a parts 
kit, was not, or did not include, a ``firearm frame or receiver'' under 
Sec.  478.11, or ``frame or receiver'' under Sec.  479.11 of this 
subchapter, as those terms were defined prior to April 26, 2022, shall 
not continue to be valid or authoritative after that date. Such 
determinations shall include those in which the Director determined 
that the item or parts kit had not yet reached a stage of manufacture 
to be, or include, a ``firearm frame or receiver'' under Sec.  478.11, 
or ``frame or receiver'' under Sec.  479.11 of this subchapter, as 
those terms were defined prior to [date of publication of the rule].


Sec.  478.47   [Amended]

0
8. In Sec.  478.47 amend paragraph (a) by removing the words ``serial 
number'' and adding in its place ``unique license number''.


Sec.  478.50   [Amended]

0
9. In Sec.  478.50 amend paragraph (a) by adding the phrase ``, or if 
such warehouse is used by the licensee for the storage of records as 
provided in Sec.  478.129'' after the phrase ``at the licensed premises 
served by such warehouse''.


Sec.  478.92   [Amended]

0
10. Amend Sec.  478.92 by revising paragraph (a) and adding paragraph 
(c) to read as follows:


Sec.  478.92   Identification of firearms and armor piercing 
ammunition.

    (a)(1) Firearms manufactured or imported by licensees. Except as 
otherwise provided in this section, licensed manufacturers and licensed 
importers of firearms must legibly identify each firearm they 
manufacture or import as follows:
    (i) Serial number, name, place of business. By engraving, casting, 
stamping (impressing), or otherwise conspicuously placing or causing to 
be engraved, cast, stamped (impressed) or otherwise placed on the frame 
or receiver thereof, an individual serial number, in a manner not 
susceptible of being readily obliterated, altered, or removed. The 
serial number must not duplicate any serial number placed by the 
licensee on any other firearm. The frame or receiver must also be 
marked with either: their name (or recognized abbreviation), and city 
and State (or recognized abbreviation) where they maintain their place 
of business; or their name (or recognized abbreviation) and the serial 
number beginning with their abbreviated Federal firearms license 
number, which is the first three and last five digits, as a prefix to 
the unique identification number, followed by a hyphen, e.g., 
``12345678-[unique identification number]''; and
    (ii) Model, caliber or gauge, foreign manufacturer, country of 
manufacture. By engraving, casting, stamping (impressing), or otherwise 
conspicuously placing or causing to be engraved, cast, stamped 
(impressed) or placed on the frame or receiver, or barrel or pistol 
slide (if applicable) thereof, certain additional information. This 
information must be placed in a manner not susceptible of being readily 
obliterated, altered, or removed. The additional information shall 
include:
    (A) The model, if such designation has been made;
    (B) The caliber or gauge;
    (C) When applicable, the name of the foreign manufacturer; and
    (D) In the case of an imported firearm, the name of the country in 
which it was manufactured. For additional requirements relating to 
imported firearms, see Customs regulations at 19 CFR part 134.
    (iii) Multi-piece frame or receiver. In the case of a multi-piece 
frame or receiver, the modular subpart that is the outermost housing or 
structure designed to house, hold, or contain either the primary 
energized component of a handgun, breech blocking or sealing component 
of a projectile weapon other than a handgun, or internal sound 
reduction component of a firearm muffler or firearm silencer, as the 
case may be, shall be the subpart of the multi-piece frame or receiver 
identified in accordance with this section. If more than one subpart is 
similarly designed to house, hold, or contain such primary component 
(e.g., left and right halves), each of those subparts must be 
identified with the same serial number and associated licensee 
information not duplicated on any other frame or receiver. The 
identified subpart(s) of a complete (assembled or unassembled) multi-
piece frame or receiver shall not be removed and replaced (see Sec.  
478.34, 18 U.S.C. 922(k), and 26 U.S.C. 5861(g) and (h)), unless--
    (A) The subpart replacement is not a firearm under 26 U.S.C. 5845;
    (B) The subpart replacement is identified by the licensed 
manufacturer of the original subpart with the same serial number and 
associated licensee information in the manner prescribed by this 
section; and
    (C) The original subpart is destroyed under the licensed 
manufacturer's control or direct supervision prior to such placement.
    (iv) Frame or receiver, machinegun conversion part, or muffler or 
silencer part disposed of separately. Each part defined as a frame or 
receiver or modular subpart thereof described in paragraph (a)(1)(iii) 
of this section, machinegun, or firearm muffler or firearm silencer 
that is not a component part of a complete weapon or complete muffler 
or silencer device at the time it is sold, shipped, or otherwise 
disposed of by the licensee must be identified as required by this 
section with an individual serial number not duplicated on any other 
firearm and all additional identifying information, except that the 
model designation and caliber or gauge may be omitted if that 
information is

[[Page 24742]]

unknown at the time the part is identified.
    (v) Size and depth of markings. The engraving, casting, or stamping 
(impressing) of the serial number and additional information must be to 
a minimum depth of .003 inch, and the serial number and any associated 
license number in a print size no smaller than \1/16\ inch. The size of 
the serial and license number is measured as the distance between the 
latitudinal ends of the character impression bottoms (bases). The depth 
of all markings required by this section is measured from the flat 
surface of the metal and not the peaks or ridges.
    (vi) Period of time to identify firearms. Licensed manufacturers 
shall identify firearms they manufacture within the period of time set 
forth in the following subparagraphs (A) and (B), and licensed 
importers must identify firearms they import within the period 
prescribed in Sec.  478.112. For purposes of these subparagraphs, 
firearms awaiting materials, parts, or equipment repair to be completed 
are presumed, absent reliable evidence to the contrary, to be in the 
manufacturing process.
    (A) Complete non-National Firearms Act weapons, and frames or 
receivers of such weapons. Complete weapons not defined as firearms 
under 26 U.S.C. 5845 shall be identified not later than the seventh day 
following the date the entire manufacturing process has ended for the 
weapon, or prior to disposition, whichever is sooner. Each part, 
including a replacement part, defined as a frame or receiver or modular 
subpart thereof described in paragraph (a)(1)(iii) of this section 
(other than a machinegun or firearm muffler or firearm silencer) that 
is not a component part of a complete weapon at the time it is sold, 
shipped, or otherwise disposed of shall be identified not later than 
the seventh day following the date the entire manufacturing process has 
ended for the frame or receiver or modular subpart, or prior to 
disposition, whichever is sooner.
    (B) Complete National Firearms Act weapons and devices, and 
machinegun and muffler or silencer parts. Complete weapons defined as 
firearms under 26 U.S.C. 5845, and complete muffler or silencer 
devices, shall be identified not later than close of the next business 
day following the date the entire manufacturing process has ended for 
the weapon or device, or prior to disposition, whichever is sooner. 
Each part or modular subpart defined as a machinegun (i.e., frame or 
receiver or conversion part), or firearm muffler or firearm silencer, 
that is not a component part of a complete weapon or complete firearm 
muffler or silencer device at the time it is sold, shipped, or 
otherwise disposed of shall be identified not later than close of the 
next business day following the date the entire manufacturing process 
has ended for the part, or prior to disposition, whichever is sooner.
    (2) Privately made firearms (PMFs). Unless previously identified by 
another licensee in accordance with, and except as otherwise provided 
by, this section, licensees must legibly and conspicuously identify 
each privately made firearm or ``PMF'' received or otherwise acquired 
(including from a personal collection) not later than the seventh day 
following the date of receipt or other acquisition, or before the date 
of disposition (including to a personal collection), whichever is 
sooner. PMFs must be identified by placing, or causing to be placed 
under the licensee's direct supervision, an individual serial number on 
the frame or receiver, which must not duplicate any serial number 
placed by the licensee on any other firearm. The serial number must 
begin with the licensee's abbreviated Federal firearms license number, 
which is the first three and last five digits, as a prefix to a unique 
identification number, followed by a hyphen, e.g., ``12345678-[unique 
identification number]''. The serial number must be placed in a manner 
otherwise in accordance with this section, including the requirements 
that the serial number be at the minimum size and depth, and not 
susceptible of being readily obliterated, altered, or removed. An 
acceptable method of identifying a PMF is by placing the serial number 
on a metal plate that is permanently embedded into a polymer frame or 
receiver, or other method approved by the Director.
    (3) Meaning of marking terms. For purposes of this section, the 
term ``identify'' means placing marks of identification, the terms 
``legible'' and ``legibly'' mean that the identification markings 
(including a unique identification number) use exclusively Roman 
letters (e.g., A, a, B, b, C, c) and Arabic numerals (e.g., 1, 2, 3), 
or solely Arabic numerals, and may include a hyphen, and the terms 
``conspicuous'' and ``conspicuously'' mean that the identification 
markings are capable of being easily seen with the naked eye during 
normal handling of the firearm, and are unobstructed by other markings 
when the complete weapon or device is assembled.
    (4) Exceptions--(i) Alternate means of identification. The Director 
may authorize other means of identification to identify firearms upon 
receipt of a letter application or prescribed form from the licensee 
showing that such other identification is reasonable and will not 
hinder the effective administration of this part.
    (ii) Destructive devices. In the case of a destructive device, the 
Director may authorize other means of identification to identify that 
weapon upon receipt of a letter application or prescribed form from the 
licensee. The application shall show that engraving, casting, or 
stamping (impressing) such a weapon as required by this section would 
be dangerous or impracticable and that the alternate means of 
identification proposed will not hinder the effective administration of 
this part.
    (iii) Adoption of identifying markings. Licensees may adopt 
existing markings previously placed on a firearm and are not required 
to mark a serial number or other identifying markings in accordance 
with this section, as follows:
    (A) Newly manufactured firearms: Licensed manufacturers may adopt 
the serial number and other identifying markings previously placed on a 
firearm by another licensed manufacturer provided the firearm has not 
been sold, shipped, or otherwise disposed of to a person other than a 
licensee, and the serial number adopted is not duplicated on any other 
firearm.
    (B) Remanufactured or imported firearms. Licensed manufacturers and 
licensed importers may adopt the serial number or other identifying 
markings previously placed on a firearm that otherwise meets the 
requirements of this section that has been sold, shipped, or otherwise 
disposed of to a person other than a licensee provided that, within the 
period and in the manner herein prescribed, the licensee legibly and 
conspicuously places, or causes to be placed, on the frame or receiver 
either: Their name (or recognized abbreviation), and city and State (or 
recognized abbreviation) where they maintain their place of business; 
or their name (or recognized abbreviation) and abbreviated Federal 
firearms license number, which is the first three and last five digits, 
individually (i.e., not as a prefix to the serial number adopted) after 
the letters ``FFL'', in the following format: ``FFL12345678''. The 
serial number adopted must not duplicate any serial number adopted or 
placed on any other firearm, except that if a licensed importer 
receives two or more firearms with the same foreign manufacturer's 
serial number, the importer may adopt the serial number by adding 
letters or numbers to that serial number, and may include a hyphen.
    (C) Manufacturers performing gunsmithing services. Licensed

[[Page 24743]]

manufacturers may adopt the serial number or other identifying markings 
previously placed on a firearm by another licensee provided the 
manufacturer is performing services for a nonlicensee as a gunsmith (as 
defined in Sec.  478.11) on existing firearms not for sale or 
distribution.
    (D) Privately made firearms marked by nonlicensees. Unless 
previously identified by another licensee in accordance with this 
section, licensees may adopt a unique identification number previously 
placed on a privately made firearm by an unlicensed person, but not 
duplicated on any other firearm of the licensee, that otherwise meets 
the identification requirements of this section provided that, within 
the period and in the manner herein prescribed, the licensee legibly 
and conspicuously places, or causes to be placed, on the frame or 
receiver thereof a serial number beginning with their abbreviated 
Federal firearms license number, which is the first three and last five 
digits, followed by a hyphen, before the existing unique identification 
number, e.g., ``12345678-[unique identification number]''.
    (iv)(A) Firearm muffler or silencer parts transferred between 
qualified manufacturers for further manufacture or to complete new 
devices. Licensed manufacturers qualified under 27 CFR part 479 may 
transfer a part defined as a firearm muffler or firearm silencer to 
another qualified manufacturer without immediately identifying or 
registering such part provided that it is for further manufacture 
(i.e., machining, coating, etc.) or manufacturing a complete muffler or 
silencer device. Once the new device with such part is completed, the 
manufacturer who completes the device shall identify, record, and 
register it in the manner and within the period specified in this part 
for a complete muffler or silencer device.
    (B) Firearm muffler or silencer replacement parts transferred to 
qualified manufacturers or dealers to repair existing devices. Licensed 
manufacturers qualified under part 479 may transfer a replacement part 
defined as a firearm muffler or firearm silencer other than a frame or 
receiver to a qualified manufacturer or dealer without identifying or 
registering such part provided that it is for repairing a complete 
muffler or silencer device that was previously identified, recorded, 
and registered in accordance with this part and part 479.
    (v) Frames or receivers designed before August 24, 2022. Licensed 
manufacturers and licensed importers may continue to identify the same 
component of a firearm (other than a PMF) defined as a frame or 
receiver as it existed before August 24, 2022 with the same information 
required to be marked by paragraphs (a)(1)(i) and (a)(1)(ii) of this 
section that were in effect prior to that date, and any rules necessary 
to ensure such identification shall remain effective for that purpose. 
Any frame or receiver with a new design manufactured after August 24, 
2022 must be marked with the identifying information and within the 
period prescribed by this section. For purposes of this paragraph, the 
term ``new design'' means that the design of the existing frame or 
receiver has been functionally modified or altered, as distinguished 
from performing a cosmetic process that adds to or changes the 
decoration of the frame or receiver (e.g., painting or engraving), or 
by adding or replacing stocks, barrels, or accessories to the frame or 
receiver.
    (vi) Privately made firearms acquired before August 24, 2022. 
Licensees shall identify in the manner prescribed by this section, or 
cause another person to so identify, each privately made firearm 
received or otherwise acquired (including from a personal collection) 
by the licensee before August 24, 2022within sixty (60) days from that 
date, or prior to the date of final disposition (including to a 
personal collection), whichever is sooner.
* * * * *
    (c) Voluntary classification of firearms and armor piercing 
ammunition. The Director may issue a determination (classification) to 
a person whether an item, including a kit, is a firearm or armor 
piercing ammunition as defined in this part upon receipt of a written 
request or form prescribed by the Director. Each such voluntary request 
or form submitted shall be executed under the penalties of perjury with 
a complete and accurate description of the item or kit, the name and 
address of the manufacturer or importer thereof, and a sample of such 
item or kit for examination. A firearm sample must include all 
accessories and attachments relevant to such classification as each 
classification is limited to the firearm in the configuration 
submitted. Each request for classification of a partially complete, 
disassembled, or nonfunctional item or kit must contain any associated 
templates, jigs, molds, equipment, or tools that are made available by 
the seller or distributor of the item or kit to the purchaser or 
recipient of the item or kit, and any instructions, guides, or 
marketing materials if they will be made available by the seller or 
distributor with the item or kit. Upon completion of the examination, 
the Director may return the sample to the person who made the request 
unless a determination is made that return of the sample would be or 
place the person in violation of law. Submissions of armor piercing 
ammunition with a projectile or projectile core constructed entirely 
from one or a combination of tungsten steel alloys, steel, iron, brass, 
bronze, beryllium copper, or depleted uranium must include a list of 
known handguns in which the ammunition may be used. Except for the 
classification of a specific component as the frame or receiver of a 
particular weapon, a determination made by the Director under this 
paragraph shall not be deemed by any person to be applicable to or 
authoritative with respect to any other sample, design, model, or 
configuration.

0
11. Revise Sec.  478.122 to read as follows:


Sec.  478.122   Records maintained by importers.

    (a) Except for adjustment or repair of a firearm that is returned 
to the person from whom it was received on the same day, each licensed 
importer shall record the name of the importer and manufacturer, type, 
model, caliber or gauge, country or countries of manufacture (if 
imported), and serial number (including any associated license number 
either as a prefix, or if remanufactured or imported, separated by a 
semicolon) of each firearm imported or otherwise acquired (including a 
frame or receiver to be disposed of separately), the date of such 
importation or other acquisition, and if otherwise acquired, the name 
and address, or the name and license number of the person from whom it 
was received. Privately made firearms shall be recorded in accordance 
with Sec.  478.125(i). The information required by this paragraph shall 
be recorded not later than 15 days following the date of importation or 
other acquisition in a format containing the applicable columns set 
forth in paragraph (b) of this section.
    (b) A record of each firearm disposed of by an importer and a 
separate record of armor piercing ammunition dispositions to 
governmental entities, for exportation, or for testing or 
experimentation authorized under the provisions of Sec.  478.149 shall 
be maintained by the licensed importer on the licensed premises. The 
record shall show the date of such sale or other disposition, and the 
name and license number of the licensee to whom the firearm was 
transferred, or if disposed of to a nonlicensee, the name and address 
of the person, or the transaction number

[[Page 24744]]

of the Firearms Transaction Record, Form 4473, if the licensee 
transferring the firearm sequentially numbers the Forms 4473 and files 
them numerically. In the event the licensee records a duplicate entry 
with the same firearm and acquisition information, whether to close out 
an old record book or for any other reason, the licensee shall record a 
reference to the date and location of the subsequent entry (e.g., date 
of new entry, book name/number, page number, and line number) as the 
disposition. The information required by this paragraph (b) shall be 
entered in the proper record book not later than the seventh day 
following the date of the transaction. Such information shall be 
recorded in formats containing the applicable columns below, except 
that for armor piercing ammunition, the information and format shall 
also include the quantity of projectiles:

                                                 Table 1 to Paragraph (b)--Firearms Importer or Manufacturer Acquisition and Disposition Record
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Description of firearm                                                   Import/manufacture/acquisition                Disposition
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                                                    Address of
                                                                                                                                             Name and                              nonlicensee;
                                                                                                                                            address of                            license No. of
                                                                                                 Country or                   Date of      nonlicensee;                            licensee; or
 Importer,  manufacturer, and/or ``privately made firearm''      Type      Model     Caliber    countries of     Serial       import,          or if        Date of       Name       Form 4473
           (PMF)  (if privately made in the U.S.)                                    or gauge    manufacture      No.      manufacture,   licensee, name  disposition               transaction
                                                                                                (if imported)             or acquisition   and  license                             No. if such
                                                                                                                                             No.  (if                               forms filed
                                                                                                                                             acquired)                              numerically
 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


         Table 2 to Paragraph (b)--Armor Piercing Ammunition Importer or Manufacturer Disposition Record
----------------------------------------------------------------------------------------------------------------
                                                             Caliber or  Quantity of     Transferee--name and
        Date of  disposition              Manufacturer         gauge     projectiles            address
 
----------------------------------------------------------------------------------------------------------------

    (c) The Director may authorize alternate records to be maintained 
by a licensed importer to record the acquisition and disposition of 
firearms and armor piercing ammunition when it is shown by the licensed 
importer that such alternate records will accurately and readily 
disclose the information required by this section. A licensed importer 
who proposes to use alternate records shall submit a letter application 
to the Director and shall describe the proposed alternate records and 
the need therefor. Such alternate records shall not be employed by the 
licensed importer until approval in such regard is received from the 
Director.

0
12. Revise Sec.  478.123 to read as follows:


Sec.  478.123   Records maintained by manufacturers.

    (a) Except for adjustment or repair of a firearm that is returned 
to the person from whom it was received on the same day, each licensed 
manufacturer shall record the name of the manufacturer and importer (if 
any), type, model, caliber or gauge, and serial number (including any 
associated license number either as a prefix, or if remanufactured or 
imported, separated by a semicolon) of each firearm manufactured or 
otherwise acquired (including a frame or receiver to be disposed of 
separately), the date of such manufacture or other acquisition, and if 
otherwise acquired, the name and address or the name and license number 
of the person from whom it was received. Privately made firearms shall 
be recorded in accordance with Sec.  478.125(i). The information 
required by this paragraph shall, in the case of a firearm other than a 
firearm defined in 26 U.S.C. 5845, be recorded not later than the 
seventh day following the date of such manufacture or other 
acquisition. In the case of a firearm defined in 26 U.S.C. 5845, such 
information shall be recorded by close of the next business day 
following the date of such manufacture or other acquisition, except 
that, when a commercial record is held by the licensed manufacturer 
separately from other commercial documents and readily available for 
inspection, containing all acquisition information required for the 
record, the period for making the required entry into the record may be 
delayed not to exceed the seventh day following the date of receipt. 
The information required by this paragraph shall be recorded in a 
format containing the applicable columns prescribed by Sec.  478.122.
    (b) A record of each firearm disposed of by a manufacturer and a 
separate record of armor piercing ammunition dispositions to 
governmental entities, for exportation, or for testing or 
experimentation authorized under the provisions of Sec.  478.149 shall 
be maintained by the licensed manufacturer on the licensed premises. 
The record shall show the date of such sale or other disposition, and 
the name and license number of the licensee to whom the firearms were 
transferred, or if disposed of to a nonlicensee, the name and address 
of the person, or the transaction number of the Firearms Transaction 
Record, Form 4473, if the licensee transferring the firearm 
sequentially numbers the Forms 4473 and files them numerically. In the 
event the licensee records a duplicate entry with the same firearm and 
acquisition information, whether to close out an old record book or for 
any other reason, the licensee shall record a reference to the date and 
location of the subsequent entry (e.g., date of new entry, book name/
number, page number, and line number) as the disposition. The 
information required by this paragraph shall be entered in the proper 
record book not later than the seventh day following the date of the 
transaction. Such information shall be recorded in a format containing 
the applicable columns prescribed by Sec.  478.122, except that for 
armor piercing ammunition, the information and format shall also 
include the quantity of projectiles.
    (c) The Director may authorize alternate records to be maintained 
by a licensed manufacturer to record the acquisition or disposition of 
firearms and armor piercing ammunition when it is shown by the licensed 
manufacturer that such alternate records will accurately and readily 
disclose the information required by this section. A licensed 
manufacturer who proposes to use alternate records shall submit a 
letter application to the Director and shall describe the proposed 
alternate record and the need therefor. Such alternate records shall 
not be employed by the licensed manufacturer until approval in such 
regard is received from the Director.

0
13. Amend Sec.  478.124 by:

[[Page 24745]]

0
a. In paragraph (b) removing the word ``serial'' before ``number'';
0
b. Revising paragraph (c)(4); and
0
c. In paragraph (f) revising the fourth sentence and adding a new fifth 
sentence.
    The addition and revision read as follows:


Sec.  478.124   Firearms transaction record.

* * * * *
    (c) * * *
    (4) The licensee shall identify the firearm to be transferred by 
listing on the Form 4473 the name of the manufacturer, the name of the 
importer (if any), the type, model, caliber or gauge, and the serial 
number (including any associated license number either as a prefix, or 
if remanufactured or imported, separated by a semicolon) of the 
firearm. Where no manufacturer name has been identified on a privately 
made firearm, the words ``privately made firearm'' (or abbreviation 
``PMF'') shall be recorded as the name of the manufacturer.
* * * * *
    (f) * * * The licensee shall identify the firearm to be transferred 
by listing in the Forms 4473 the name of the manufacturer, the name of 
the importer (if any), the type, model, caliber or gauge, and the 
serial number of the firearm to be transferred. Where no manufacturer 
name has been identified on a privately made firearm, the words 
``privately made firearm'' (or abbreviation ``PMF'') shall be recorded 
as the name of the manufacturer. * * *
* * * * *

0
14. Amend Sec.  478.125 by revising paragraphs (e), (f) and (i) to read 
as follows:


Sec.  478.125   Record of receipt and disposition.

* * * * *
    (e) Firearms receipt and disposition by dealers. Except for 
adjustment or repair of a firearm that is returned to the person from 
whom it was received on the same day, each licensed dealer shall enter 
into a record each receipt and disposition of firearms. In addition, 
before commencing or continuing a firearms business, each licensed 
dealer shall inventory the firearms possessed for such business and 
shall record the same in the record required by this paragraph. The 
record required by this paragraph shall be maintained in bound form in 
the format prescribed below. The purchase or other acquisition of a 
firearm shall, except as provided in paragraphs (g) and (i) of this 
section, be recorded not later than the close of the next business day 
following the date of such purchase or acquisition. The record shall 
show the date of receipt, the name and address or the name and license 
number of the person from whom received, the name of the manufacturer 
and importer (if any), the model, serial number (including any 
associated license number either as a prefix, or if remanufactured or 
imported, separated by a semicolon), type, and the caliber or gauge of 
the firearm. In the event the licensee records a duplicate entry with 
the same firearm and acquisition information, whether to close out an 
old record book or for any other reason, the licensee shall record a 
reference to the date and location of the subsequent entry (e.g., date 
of new entry, book name/number, page number, and line number) as the 
disposition. The sale or other disposition of a firearm shall be 
recorded by the licensed dealer not later than seven days following the 
date of such transaction. When such disposition is made to a 
nonlicensee, the firearms transaction record, Form 4473, obtained by 
the licensed dealer shall be retained, until the transaction is 
recorded, separate from the licensee's Form 4473 file and be readily 
available for inspection. When such disposition is made to a licensee, 
the commercial record of the transaction shall be retained, until the 
transaction is recorded, separate from other commercial documents 
maintained by the licensed dealer, and be readily available for 
inspection. The record shall show the date of the sale or other 
disposition of each firearm, the name and address of the person to whom 
the firearm is transferred, or the name and license number of the 
person to whom transferred if such person is a licensee, or the 
firearms transaction record, Form 4473, transaction number if the 
licensed dealer transferring the firearm sequentially numbers the Forms 
4473 and files them numerically. The format required for the record of 
receipt and disposition of firearms is as follows:

                                      Table 2 to Paragraph (e)--Firearms Dealer Acquisition and Disposition Record
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Description of firearm                                         Receipt                            Disposition
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                          Address of
                                                                                                                                         nonlicensee;
 Manufacturer, importer (if any),                                                         Name and address of                           license No. of
  or  ``privately made firearm''     Model      Serial      Type     Caliber      Date    nonlicensee;  or if     Date       Name     licensee; or Form
              (PMF)                              No.                 or gauge              licensee, name and                          4473 transaction
                                                                                              license No.                             No.  if such forms
                                                                                                                                      filed numerically
 
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (f) Firearms receipt and disposition by licensed collectors. (1) 
Each licensed collector shall enter into a record each receipt and 
disposition of firearms curios or relics. The record required by this 
paragraph shall be maintained in bound form under the format prescribed 
below. The purchase or other acquisition of a curio or relic shall, 
except as provided in paragraphs (g) and (i) of this section, be 
recorded not later than the close of the next business day following 
the date of such purchase or other acquisition. The record shall show 
the date of receipt, the name and address or the name and license 
number of the person from whom received, the name of the manufacturer 
and importer (if any), the model, serial number (including any 
associated license number either as a prefix, or if remanufactured or 
imported, separated by a semicolon), type, and the caliber or gauge of 
the firearm curio or relic. In the event the licensee records a 
duplicate entry with the same firearm and acquisition information, 
whether to close out an old record book or for any other reason, the 
licensee shall record a reference to the date and location of the 
subsequent entry (e.g., date of new entry, book name/number, page 
number, and line number) as the disposition. The sale or other 
disposition of a curio or relic shall be recorded by the licensed 
collector not later than seven days following the date of such 
transaction. When such disposition is made to a licensee, the 
commercial record of the transaction shall be retained, until the 
transaction is recorded, separate from other commercial documents 
maintained by the licensee, and be readily available for inspection. 
The record shall show the date of the sale or other disposition of each 
firearm curio or relic, the name and address of the person to whom the 
firearm curio or relic is transferred, or the name and license number 
of the person to whom transferred if such person is a licensee,

[[Page 24746]]

and the date of birth of the transferee if other than a licensee. In 
addition, the licensee shall cause the transferee, if other than a 
licensee, to be identified in any manner customarily used in commercial 
transactions (e.g., a driver's license), and note on the record the 
method used.
    (2) The format required for the record of receipt and disposition 
of firearms by collectors is as follows:

                                                       Table 3 to Paragraph (f)(2)--Firearms Collector Acquisition and Disposition Record
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                            Description of firearm                                           Receipt                                                Disposition
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Name and  address of              Name and  address of                          Driver's license No.
Manufacturer,  importer  (if any),               Serial               Caliber               nonlicensee; or  if               nonlicensee; or  if      Date of birth if           or other
   or ``privately  made firearm''     Model       No.        Type     or gauge     Date      licensee, name and      Date      licensee, name and        nonlicensee         identification if
               (PMF)                                                                            license No.                       license No.                                   nonlicensee
 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
    (i) Privately made firearms. Except for adjustment or repair of a 
firearm that is returned to the person from whom it was received on the 
same day, licensees must record each receipt or other acquisition 
(including from a personal collection) and disposition (including to a 
personal collection) of a privately made firearm as required by this 
part. For purposes of this paragraph, the terms ``receipt'' and 
``acquisition'' shall include same-day or on-the-spot placement of 
identifying markings unless another licensee is placing the markings 
for, and under the direct supervision of, the licensee who recorded the 
acquisition. In that case, the licensee placing the markings need not 
record an acquisition from the supervising licensee or disposition upon 
return. The serial number need not be immediately recorded if the 
firearm is being identified by the licensee, or under the licensee's 
direct supervision with the licensee's serial number, in accordance 
with Sec.  478.92(a)(2). Once the privately made firearm is so 
identified, the licensee shall update the record of acquisition entry 
with the serial number, including the license number prefix, and shall 
record its disposition in accordance with this section. In this part 
and part 447, where no manufacturer name has been identified on a 
privately made firearm (if privately made in the United States), the 
words ``privately made firearm'' (or abbreviation ``PMF'') shall be 
recorded as the name of the manufacturer.

0
15. In Sec.  478.125a amend paragraph (a)(4) by:
0
a. In the first sentence removing the words ``serial number'' and add 
in their place ``serial number (including any associated license number 
either as a prefix, or if remanufactured or imported, separated by a 
semicolon)'';
0
b. Adding a new third sentence; and
0
c. Designating the table as table 1 and revising newly designated table 
1.
    The addition and revision read as follows:


Sec.  478.125a   Personal firearms collection.

    (a) * * *
    (4) * * * Where no manufacturer name has been identified on a 
privately made firearm, the words ``privately made firearm'' (or 
abbreviation ``PMF'') shall be recorded as the name of the 
manufacturer. * * *

                                          Table 1 to Paragraph (a)(4)--Disposition Record of Personal Firearms
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Description of firearm                                                             Disposition
--------------------------------------------------------------------------------------------------------------------------------------------------------
 Manufacturer, importer (if any),                                                                                     Name and address
  or ``privately made  firearm''         Model        Serial No.         Type         Caliber or         Date       (business address if   Date of birth
               (PMF)                                                                     gauge                            licensee)       if nonlicensee
 
--------------------------------------------------------------------------------------------------------------------------------------------------------


0
16. Amend Sec.  478.129 by revising paragraphs (b), (d) and (e) to read 
as follows:


Sec.  478.129   Record retention.

* * * * *
    (b) Firearms Transaction Record. Licensees shall retain each Form 
4473 until business or licensed activity is discontinued, either on 
paper, or in an electronic alternate method approved by the Director, 
at the business premises readily accessible for inspection under this 
part. Paper forms over 20 years of age may be stored at a separate 
warehouse, which shall be considered part of the business premises for 
this purpose and subject to inspection under this part. Forms 4473 
shall be retained in the licensee's records as provided in Sec.  
478.124(b), provided that Forms 4473 with respect to which a sale, 
delivery, or transfer did not take place shall be separately retained 
in alphabetical (by name of transferee) or chronological (by date of 
transferee's certification) order.
* * * * *
    (d) Records of importation and manufacture. Licensees shall 
maintain records of the importation, manufacture, or other acquisition 
of firearms, including ATF Forms 6 and 6A as required by subpart G of 
this part, until business or licensed activity is discontinued. 
Licensed importers' records and licensed manufacturers' records of the 
sale or other disposition of firearms after December 15, 1968, shall be 
retained until business is discontinued, either on paper or in an 
electronic alternate method approved by the Director, at the business 
premises readily accessible for inspection under this part. Paper 
records that do not contain any open disposition entries and with no 
dispositions recorded within 20 years may be stored at a separate 
warehouse, which shall be considered part of the business premises for 
this purpose and subject to inspection under this part.
    (e) Records of dealers and collectors. The records prepared by 
licensed dealers and licensed collectors of the sale or other 
disposition of firearms and the corresponding record of receipt of such 
firearms shall be retained until business or licensed activity is 
discontinued, either on paper, or in an electronic alternate method 
approved by the Director, at the business or collection premises 
readily accessible for inspection under this part. Paper records that 
do not contain any open disposition entries and with no dispositions 
recorded within 20 years

[[Page 24747]]

may be stored at a separate warehouse, which shall be considered part 
of the business or collection premises for this purpose and subject to 
inspection under this part.
* * * * *

PART 479--MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER 
FIREARMS

0
17. The authority citation for part 479 continues to read as follows:

    Authority: 26 U.S.C. 5812; 26 U.S.C. 5822; 26 U.S.C. 7801; 26 
U.S.C. 7805.


Sec.  479.11  [Revised]

0
18. Amend Sec.  479.11 as follows:
0
a. Add, in alphabetical order, definitions for ``Complete muffler or 
silencer device'' and ``Complete weapon'';
0
b. Revise the definition of ``Frame or receiver'';
0
c. Add the definition of ``Readily''; and
0
d. Add a sentence at the end of the definition of ``Transfer''.
    The additions and revisions read as follows:


Sec.  479.11  Meaning of terms.

* * * * *
    Complete muffler or silencer device. A muffler or silencer that 
contains all component parts necessary to function, whether or not 
assembled or operable.
    Complete weapon. A firearm other than a muffler or silencer that 
contains all component parts necessary to function, whether or not 
assembled or operable.
* * * * *
    Frame or receiver. The term ``frame or receiver'' shall have the 
same meaning as in Sec.  478.12 of this subchapter.
* * * * *
    Readily. A process, action, or physical state that is fairly or 
reasonably efficient, quick, and easy, but not necessarily the most 
efficient, speediest, or easiest process, action, or physical state. 
With respect to the classification of firearms, factors relevant in 
making this determination include the following:
    (1) Time, i.e., how long it takes to finish the process;
    (2) Ease, i.e., how difficult it is to do so;
    (3) Expertise, i.e., what knowledge and skills are required;
    (4) Equipment, i.e., what tools are required;
    (5) Parts availability, i.e., whether additional parts are 
required, and how easily they can be obtained;
    (6) Expense, i.e., how much it costs;
    (7) Scope, i.e., the extent to which the subject of the process 
must be changed to finish it; and
    (8) Feasibility, i.e., whether the process would damage or destroy 
the subject of the process, or cause it to malfunction.
* * * * *
    Transfer. * * * For purposes of this part, the term shall not 
include the temporary conveyance of a lawfully possessed firearm to a 
manufacturer or dealer qualified under this part for the sole purpose 
of repair, identification, evaluation, research, testing, or 
calibration and return to the same lawful possessor.
* * * * *

0
19. Revise Sec.  479.102 to read as follows:


Sec.  479.102  Identification of firearms.

    (a) Identification required. Except as otherwise provided in this 
section, you, as a manufacturer, importer, or maker of a firearm, must 
legibly identify the firearm as follows:
    (1) Serial number, name, place of business. By engraving, casting, 
stamping (impressing), or otherwise conspicuously placing or causing to 
be engraved, cast, stamped (impressed) or otherwise placed on the frame 
or receiver thereof, an individual serial number, in a manner not 
susceptible of being readily obliterated, altered, or removed. The 
serial number must not duplicate any serial number placed by you on any 
other firearm. The frame or receiver must also be marked with either: 
Your name (or recognized abbreviation), and city and State (or 
recognized abbreviation) where you as a manufacturer or importer 
maintain your place of business, or in the case of a maker, where you 
made the firearm; or if a manufacturer or importer, your name (or 
recognized abbreviation) and the serial number that begins with your 
abbreviated Federal firearms license number, which is the first three 
and last five digits, as a prefix to a unique identification number, 
followed by a hyphen, e.g., ``12345678-[unique identification 
number]''; and
    (2) Model, caliber or gauge, foreign manufacturer, country of 
manufacture. By engraving, casting, stamping (impressing), or otherwise 
conspicuously placing or causing to be engraved, cast, stamped 
(impressed) or placed on the frame or receiver, or barrel or pistol 
slide (if applicable) thereof certain additional information. This 
information must be placed in a manner not susceptible of being readily 
obliterated, altered, or removed. The additional information shall 
include:
    (i) The model, if such designation has been made;
    (ii) The caliber or gauge;
    (iii) When applicable, the name of the foreign manufacturer or 
maker; and
    (iv) In the case of an imported firearm, the name of the country in 
which it was manufactured. For additional requirements relating to 
imported firearms, see Customs regulations at 19 CFR part 134.
    (3) Multi-piece frame or receiver. In the case of a multi-piece 
frame or receiver, the modular subpart that is the outermost housing or 
structure designed to house, hold, or contain either the primary 
energized component of a handgun, breech blocking or sealing component 
of a projectile weapon other than a handgun, or internal sound 
reduction component of a firearm muffler or firearm silencer, as the 
case may be, shall be the subpart of a multi-piece frame or receiver 
identified in accordance with this section. If more than one subpart is 
similarly designed to house, hold, or contain such primary component 
(e.g., left and right halves), each of those subparts must be 
identified with the same serial number and associated licensee 
information not duplicated on any other frame or receiver. The 
identified subpart(s) of a complete (assembled or unassembled) multi-
piece frame or receiver shall not be removed and replaced (see Sec.  
478.34 of this subchapter, 18 U.S.C. 922(k), and 26 U.S.C. 5861(g) and 
(h)), unless--
    (A) The subpart replacement is not a firearm under 26 U.S.C. 5845;
    (B) The subpart replacement is identified by the qualified 
manufacturer of the original subpart with the same serial number and 
associated licensee information in the manner prescribed by this 
section; and
    (C) The original subpart is destroyed under the manufacturer's 
control or direct supervision prior to such placement.
    (4) Frame or receiver, machine gun conversion part, or silencer 
part disposed of separately. Each part defined as a frame or receiver 
or modular subpart thereof described in paragraph (a)(3) of this 
section, machinegun, or firearm muffler or firearm silencer that is not 
a component part of a complete weapon or complete muffler or silencer 
device at the time it is sold, shipped, or otherwise disposed of by you 
must be identified as required by this section with an individual 
serial number not duplicated on any other firearm and all additional 
identifying information, except that the model designation and caliber 
or gauge may be omitted if that information is unknown at the time the 
part is identified.

[[Page 24748]]

    (5) Size and depth of markings. The engraving, casting, or stamping 
(impressing) of the serial number and additional information must be to 
a minimum depth of .003 inch, and the serial number and any associated 
license number in a print size no smaller than \1/16\ inch. The size of 
the serial and license number is measured as the distance between the 
latitudinal ends of the character impression bottoms (bases). The depth 
of all markings required by this section is measured from the flat 
surface of the metal and not the peaks or ridges.
    (6) Period of time to identify firearms. You shall identify a 
complete weapon or complete muffler or silencer device no later than 
close of the next business day following the date the entire 
manufacturing process has ended for the weapon or device, or prior to 
disposition, whichever is sooner. You must identify each part or 
modular subpart defined as a machine gun (frame or receiver, or 
conversion part) or muffler or silencer that is not a component part of 
a complete weapon or complete muffler or silencer device at the time it 
is sold, shipped, or otherwise disposed of no later than close of the 
next business day following the date the entire manufacturing process 
has ended for the part, or prior to disposition, whichever is sooner. 
For purposes of this paragraph, firearms awaiting materials, parts, or 
equipment repair to be completed are presumed, absent reliable evidence 
to the contrary, to be in the manufacturing process. Importers must 
identify imported firearms within the period prescribed in Sec.  
478.112 of this subchapter.
    (7) Meaning of marking terms. For purposes of this section, the 
term ``identify'' means placing marks of identification, the terms 
``legible'' and ``legibly'' mean that the identification markings 
(including any unique identification number) use exclusively Roman 
letters (e.g., A, a, B, b, C, c) and Arabic numerals (e.g., 1, 2, 3), 
or solely Arabic numerals, and may include a hyphen, and the terms 
``conspicuous'' and ``conspicuously'' mean that the identification 
markings are capable of being easily seen with the naked eye during 
normal handling of the firearm and are unobstructed by other markings 
when the complete weapon or device is assembled.
    (b) Exceptions--(1) Alternate means of identification. The Director 
may authorize other means of identification to identify firearms upon 
receipt of a letter application or prescribed form from you showing 
that such other identification is reasonable and will not hinder the 
effective administration of this part.
    (2) Destructive devices. In the case of a destructive device, the 
Director may authorize other means of identification to identify that 
weapon upon receipt of a letter application or prescribed form from 
you. The application shall show that engraving, casting, or stamping 
(impressing) such a weapon as required by this section would be 
dangerous or impracticable and that the alternate means of 
identification proposed will not hinder the effective administration of 
this part.
    (3) Adoption of identifying markings. You may adopt existing 
markings and are not required to mark a serial number or other 
identifying markings previously placed on a firearm in accordance with 
this section, as follows:
    (A) Newly manufactured firearms. Manufacturers may adopt the serial 
number and other identifying markings previously placed on a firearm by 
another manufacturer provided the firearm has not been sold, shipped, 
or otherwise disposed of to a person other than a qualified 
manufacturer, importer, or dealer, and the serial number adopted is not 
duplicated on any other firearm.
    (B) Remanufactured or imported firearms. Manufacturers and 
importers may adopt the serial number or other identifying markings 
previously placed on a firearm that otherwise meets the requirements of 
this section that has been sold, shipped, or otherwise disposed of to a 
person other than a licensee provided that, within the period and in 
the manner herein prescribed, the manufacturer or importer legibly and 
conspicuously places, or causes to be placed, on the frame or receiver 
either: Their name (or recognized abbreviation), and city and State (or 
recognized abbreviation) where they maintain their place of business; 
or their name (or recognized abbreviation) and abbreviated Federal 
firearms license number, which is the first three and last five digits, 
individually (i.e., not as a prefix to the serial number adopted) after 
the letters ``FFL'', in the following format: ``FFL12345678''. The 
serial number adopted must not duplicate any serial number adopted or 
placed on any other firearm, except that if an importer receives two or 
more firearms with the same foreign manufacturer's serial number, the 
importer may adopt the serial number by adding letters or numbers to 
that serial number, and may include a hyphen.
    (C) Manufacturers performing gunsmithing services. Manufacturers 
may adopt the serial number or other identifying markings previously 
placed on a firearm by a qualified manufacturer, importer, or dealer, 
provided the manufacturer is performing services as a gunsmith (as 
defined in Sec.  478.11 of this subchapter) on existing firearms not 
for sale or distribution.
    (4)(i) Firearm muffler or silencer parts transferred between 
qualified manufacturers for further manufacture or to complete new 
devices. Manufacturers qualified under this part may transfer a part 
defined as a muffler or silencer to another qualified manufacturer 
without immediately identifying or registering such part provided that 
it is for further manufacture (i.e., machining, coating, etc.) or 
manufacturing a complete muffler or silencer device. Once the new 
device with such part is completed, the manufacturer who completes the 
device shall identify and register it in the manner and within the 
period specified in this part for a complete muffler or silencer 
device.
    (ii) Firearm muffler or silencer replacement parts transferred to 
qualified manufacturers or dealers to repair existing devices. 
Manufacturers qualified under this part may transfer a replacement part 
defined as a muffler or silencer other than a frame or receiver to a 
qualified manufacturer or dealer without identifying or registering 
such part provided that it is for repairing a complete muffler or 
silencer device that was previously identified and registered in 
accordance with this part and part 478.
    (5) Frames or receivers designed before August 24, 2022. 
Manufacturers and importers may continue to identify the same component 
of a firearm defined as a frame or receiver as it existed before August 
24, 2022 with the same information required to be marked by paragraphs 
(a)(1) and (a)(2) of this section that were in effect prior to that 
date, and any rules necessary to ensure such identification shall 
remain effective for that purpose. Any frame or receiver with a new 
design manufactured after August 24, 2022 must be marked with the 
identifying information and within the period prescribed by this 
section. For purposes of this paragraph, the term ``new design'' means 
that the design of the existing frame or receiver has been functionally 
modified or altered, as distinguished from performing a cosmetic 
process that adds to or changes the decoration of the frame or receiver 
(e.g., painting or engraving), or by adding or replacing stocks, 
barrels, or accessories to the frame or receiver.
    (c) Voluntary classification of firearms. The Director may issue a 
determination (classification) to a

[[Page 24749]]

person whether an item, including a kit, is a firearm as defined in 
this part upon receipt of a written request or form prescribed by the 
Director. Each such voluntary request or form submitted shall be 
executed under the penalties of perjury with a complete and accurate 
description of the item or kit, the name and address of the 
manufacturer or importer thereof, and a sample of such item or kit for 
examination. A firearm sample must include all accessories and 
attachments relevant to such classification as each classification is 
limited to the firearm in the configuration submitted. Each request for 
classification of a partially complete, disassembled, or nonfunctional 
item or kit must contain any associated templates, jigs, molds, 
equipment, or tools that are made available by the seller or 
distributor of the item or kit to the purchaser or recipient of the 
item or kit, and any instructions, guides, or marketing materials if 
they will be made available by the seller or distributor with the item 
or kit. Upon completion of the examination, the Director may return the 
sample to the person who made the request unless a determination is 
made that return of the sample would be or place the person in 
violation of law. Except for the classification of a specific component 
as the frame or receiver of a particular weapon, a determination made 
by the Director under this paragraph shall not be deemed by any person 
to be applicable to or authoritative with respect to any other sample, 
design, model, or configuration.


Sec.  479.103  [Amended]

0
20. In Sec.  479.103, at the beginning of the third sentence, remove 
the word ``All'' and add in its place ``Except as provided in Sec.  
479.102(b)(4), all''.

Merrick B. Garland,
Attorney General.
[FR Doc. 2022-08026 Filed 4-25-22; 8:45 am]
BILLING CODE 4410-FY-P