I 
117TH CONGRESS 
1ST SESSION H. R. 1477 
To modernize the Undetectable Firearms Act of 1988. 
IN THE HOUSE OF REPRESENTATIVES 
MARCH 2, 2021 
Ms. DEAN (for herself, Mr. LANGEVIN, Ms. JACKSON LEE, Mr. COHEN, Ms. 
NORTON, Ms. SCANLON, Mr. TRONE, Ms. HOULAHAN, Mr. BLU-
MENAUER, Mr. RASKIN, Mr. SWALWELL, Mrs. MCBATH, Mr. SOTO, Mr. 
CA´RDENAS, Mr. MICHAEL F. DOYLE of Pennsylvania, Ms. WILSON of 
Florida, Ms. SCHAKOWSKY, Mr. CICILLINE, Mr. CARSON, Ms. GARCIA of 
Texas, Mrs. CAROLYN B. MALONEY of New York, Mr. HUFFMAN, Mr. 
MALINOWSKI, Mr. HASTINGS, Mr. MCNERNEY, Mr. NORCROSS, Mr. GRI-
JALVA, Mr. KHANNA, and Mr. SCHNEIDER) introduced the following bill; 
which was referred to the Committee on the Judiciary 
A BILL 
To modernize the Undetectable Firearms Act of 1988. 
Be it enacted by the Senate and House of Representa-
tives of the United States of America in Congress assembled, 
SECTION 1. SHORT TITLE. 
This Act may be cited as the ‘‘Undetectable Firearms 
Modernization Act’’. 
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SEC. 
2. 
MODERNIZATION 
OF 
THE 
PROHIBITION 
ON 
UNDETECTABLE FIREARMS. 
Section 922(p) of title 18, United States Code, is 
amended— 
(1) in paragraph (1)— 
(A) in subparagraph (A), by striking 
‘‘grips, stocks, and magazines, is not as detect-
able as the Security Exemplar, by walk-through 
metal detectors calibrated and operated to de-
tect the Security Exemplar’’ and inserting ‘‘all 
parts other than major components, does not 
contain detectable material’’; and 
(B) in subparagraph (B), by striking 
‘‘when subjected to inspection by the types of x- 
ray machines commonly used at airports, does 
not generate’’ and inserting the following: ‘‘if 
subjected to inspection by the types of detection 
devices commonly used at airports for security 
screening, would not generate’’; 
(2) in paragraph (2)— 
(A) by striking subparagraph (B) and in-
serting the following: 
‘‘(B) the term ‘major component’, with respect 
to a firearm— 
‘‘(i) means the slide or cylinder, or the 
frame or receiver of the firearm; and 
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‘‘(ii) in the case of a rifle or shotgun, in-
cludes the barrel of the firearm; and’’; and 
(B) by striking subparagraph (C) and the 
proviso that follows and inserting the following: 
‘‘(C) the term ‘detectable material’ means mate-
rial that produces a magnetic field that is equivalent 
in strength to the magnetic field produced by 3.7 
ounces of 17–4 PH stainless steel.’’; 
(3) in paragraph (3)— 
(A) in the first sentence, by inserting 
after ‘‘of a firearm’’ the following: ‘‘, in-
cluding a prototype,’’; and 
(B) by striking the second sentence; 
and 
(4) in paragraph (5), by striking ‘‘shall not 
apply to any firearm which’’ and all that follows and 
inserting the following: ‘‘shall not apply to— 
‘‘(A) any firearm received by, in the possession 
of, or under the control of the United States; or 
‘‘(B) the manufacture, importation, possession, 
transfer, receipt, shipment, or delivery of a firearm 
by a licensed manufacturer or licensed importer pur-
suant to an existing contract with the United 
States.’’. 
Æ 
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