Source: https://www.atf.gov/firearms/firearms-guides-importation-verification-firearms-ammunition-and-implements-war-types-1
Timestamp: 2019-04-24 14:39:50+00:00

Document:
ATF F 6A, Release and Receipt of Imported Firearms, Ammunition and Implements of War is used to release firearms, firearms parts, ammunition and other defense articles to you from U.S. Customs and Border Protection officials.
As FFL importers (Types 08 or 11) and/or AECA registered importers, the information below will provide you with the procedure and process needed to ensure Customs and Border Protection (CBP) officials release your imported articles to you.
An approved ATF Form 6 permit will be returned to you along with two blank ATF Forms 6A. You must fully complete Section I of the ATF Form 6A for each incoming shipment.
27 CFR § 447.45(a) and 27 CFR § 478.112(c) impose an additional requirement on all registered and FFL (Type 08 or 11) importers. In addition to the ATF Forms 6 and 6A already required to obtain the release of firearms, firearms parts, or ammunition, you must also present to CBP officials a copy of the export license authorizing the export of the articles from the country of export. If the exporting country does not require the issuance of an export license, you instead must present a certification, signed under penalties of perjury, attesting to that effect.
CBP may conduct a physical examination of the articles to ensure the articles imported coincide with the approved Form 6 and completed Form 6A.
CBP will complete Section II of the first Form 6A if they are satisfied that the shipment of firearms(s), ammunition or implements of war is authorized by ATF. The CBP official should return the Form 6 to you and send the first Form 6A, with Section II completed, directly to FEIB.
Within 15 days after the articles have been released by CBP, including release from a CBW or FTZ the importer must complete the marking requirements of 27 CFR § 478.92 and/or § 479.102 and the record keeping requirements of 27 CFR § 478.122.
Within that same 15 days, 27 CFR § 478.112 provides that each importer of firearms must complete Section III of the second ATF Form 6A and forward it directly to FEIB. Your original signature must be placed in Item 19.
Section 478.129(d) requires licensed importers to maintain permanent records of the importation or other acquisition of firearms, including Forms 6 or 6A. To satisfy this requirement, in view of the current instructions to prepare the Form 6A in duplicate, ATF recommends that importers either retain a photocopy of the second Form 6A in their records or prepare the Form 6A in triplicate and retain the third copy in their records.

References: § 447
 § 478
 § 478
 § 479
 § 478
 § 478