§ 478.92 How must licensed manufacturers and licensed importers identify firearms, armor piercing ammunition, and large capacity ammunition feeding devices?
(a)
(1) Firearms. You, as a licensed manufacturer or licensed importer of firearms, must legibly identify each firearm manufactured or imported as follows:
(i) By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame or receiver thereof an individual serial number. The serial number must be placed in a manner not susceptible of being readily obliterated, altered, or removed, and must not duplicate any serial number placed by you on any other firearm. For firearms manufactured or imported on and after January 30, 2002, the engraving, casting, or stamping (impressing) of the serial number must be to a minimum depth of .003 inch and in a print size no smaller than 1/16 inch; and
(ii) By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame, receiver, or barrel thereof certain additional information. This information must be placed in a manner not susceptible of being readily obliterated, altered, or removed. For firearms manufactured or imported on and after January 30, 2002, the engraving, casting, or stamping (impressing) of this information must be to a minimum depth of .003 inch. The additional information includes:
(A) The model, if such designation has been made;
(B) The caliber or gauge;
(C) Your name (or recognized abbreviation) and also, when applicable, the name of the foreign manufacturer;
(D) In the case of a domestically made firearm, the city and State (or recognized abbreviation thereof) where you as the manufacturer maintain your place of business; and
(E) In the case of an imported firearm, the name of the country in which it was manufactured and the city and State (or recognized abbreviation thereof) where you as the importer maintain your place of business. For additional requirements relating to imported firearms, see Customs regulations at 19 CFR part 134.
(2) Firearm frames or receivers. A firearm frame or receiver that is not a component part of a complete weapon at the time it is sold, shipped, or otherwise disposed of by you must be identified as required by this section.
(3) Special markings for semiautomatic assault weapons, effective July 5, 1995. In the case of any semiautomatic assault weapon manufactured after September 13, 1994, you must mark the frame or receiver “RESTRICTED LAW ENFORCEMENT/GOVERNMENT USE ONLY” or, in the case of weapons manufactured for export, “FOR EXPORT ONLY,” in a manner not susceptible of being readily obliterated, altered, or removed. For weapons manufactured or imported on and after January 30, 2002, the engraving, casting, or stamping (impressing) of the special markings prescribed in this paragraph (a)(3) must be to a minimum depth of .003 inch.
(4) Exceptions.
(i) Alternate means of identification. The Director may authorize other means of identification upon receipt of a letter application from you, submitted in duplicate, 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 identifying that weapon upon receipt of a letter application from you, submitted in duplicate, showing that engraving, casting, or stamping (impressing) such a weapon would be dangerous or impracticable.
(iii) Machine guns, silencers, and parts. Any part defined as a machine gun, firearm muffler, or firearm silencer in § 478.11, that is not a component part of a complete weapon at the time it is sold, shipped, or otherwise disposed of by you, must be identified as required by this section. The Director may authorize other means of identification of parts defined as machine guns other than frames or receivers and parts defined as mufflers or silencers upon receipt of a letter application from you, submitted in duplicate, showing that such other identification is reasonable and will not hinder the effective administration of this part.
(5) Measurement of height and depth of markings. The depth of all markings required by this section will be measured from the flat surface of the metal and not the peaks or ridges. The height of serial numbers required by paragraph (a)(1)(i) of this section will be measured as the distance between the latitudinal ends of the character impression bottoms (bases). ..............