Tech Spec: V20N5

By Rick Vasquez


Firearms and how they are marked are regulated by Title 18 United States Code, Chapter 44, which is also known as the Gun Control Act (GCA). Additionally, Title 27 Code of Federal Regulations (CFR) gives further guidance on how to apply markings, where they should be applied, and in the case of the serial number, how deeply they must be applied. There are also ATF rulings that clarify the regulations and statutes.

The history of the requirement to serialize firearms is held in the National Firearms Act (NFA), the GCA, and the military requirement to mark firearms. Generally, it is stated that serial numbers were not required until the passage of the GCA in 1968. Though this date is a drop dead requirement under United States Code, that all firearms made in the United States or imported into the United States would be required to be serialized, the serial number requirements go back to the founding of our nation. In 1775 through 1778, when the first martial arms were produced at Springfield armory, an attempt was made to mark all of the lock pieces and barrels of the muskets being produced. This method of marking was abandoned and then later implemented after 1812. (Lewis, Berkeley R. Smithsonian Miscellaneous Collections, Volume (Whole Volume), Small Arms and Ammunition in the United States Service, (With Plates).

The NFA was enacted in 1934, and it required the registration of certain firearms such as machineguns, silencers, and sawed-off weapons. As part of the registration process, a serial number was required. This is, most likely, the first U. S. regulation that required serial numbers on a category of firearms.

There was still not a requirement for all commercial firearms to have a serial number, nor was there a structure that must be followed. Though it was not required, most manufacturers were applying serial numbers on firearms they produced. Many of these firearms manufacturer’s serial numbers were duplicated or used over again between models. A manufacturer could make a pistol and a shotgun and use the same serial number on both firearms. These serial numbers were basically for record keeping purposes for the manufacturer.

In the 1958, the Federal Firearms Act of 1938 was amended. The Federal Firearms Act was part of the CFR, not the law. This amendment required the following markings be applied on firearms:
A. Name of the manufacturer or importer on the firearm (could either be the manufacturer’s or the
importer’s name)
B. Country of Origin (on all imported firearms)
C. Serial Number
Location of serial number was not specific
Duplication by the manufacturer not prohibited
Regulation did not require serial numbers on
shotguns or .22 caliber rifles

The serial number was not required to be on the frame or receiver of the firearm. For firearms that had serial numbers on the barrel there was not a penalty to remove the serialized barrel.

With the passage of the GCA in 1968, specific definitions of firearms were implemented and the requirement for a serial number was formalized.

It is important to understand the definition of a firearm to understand how firearms must be marked. A firearm is defined under Title 18, United States Code, Section 921(a)(3) as (A) 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; (B) the frame or receiver of any such weapon; (C) any firearm muffler or firearm silencer; or (D) any destructive device. Such terms do not include an antique firearm.

In short, a firearm is defined according to the statute as a weapon, and the frame or receiver of a weapon is also a firearm. Title 18, U.S.C., Section 923(i) states that “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 a manner as the Attorney General shall by regulations prescribe, each firearm imported or manufactured by such importer or manufacturer.”

This section specifically states that each firearm, which once again includes the frame or receiver, must be serialized. It does not in any manner imply or state that only completed firearms must be serialized. Section 923(i) is very specific on what must be serialized. It does not spell out that if the receiver is not complete that it should not be serialized. Again, we refer back to the definition of a firearm as defined by 921(a)3(A) to be a weapon and the receiver of the weapon is a firearm. (ATF ruling 2012-1).

Under Title 27 of the Code of Federal Regulations, the marking requirements are further clarified:
§ 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 (Emphasis added). 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 there of) 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.

The serial number applied must include at least one numeric. If a person would like unique number with his name as part of the number they must include a numeric. Such as “RICK 1.” “The serial number adopted must be comprised of only a combination of Roman letters and Arabic numerals, or solely Arabic numerals, and can include a hyphen, that were conspicuously placed on the firearm.” When a manufacturer places a serial number on a firearm, that number becomes dead. Serial numbers cannot be used on other models. If a manufacturer makes more than one model or different types of firearms (pistols, rifles), the serial number used on one model cannot be used on a different model. There have been instances in which manufacturers have received firearms from customers for replacement for a variety of reasons, and have erroneously used the same serial numbers of the destroyed/defective firearms on the new firearms. This practice is completely prohibited.

Adopting serial numbers of other manufacturers:

There are many manufacturers that utilize receivers made by other manufacturers that are already serialized and marked. Because section 923(i) indicates all licensed manufacturers and importers must apply a serial number, many of these “secondary manufacturers” were adding thier serial number on receivers they used to build their firearm. It is acceptable to follow this practice, however, these multiple serial numbers and markings could impede a successful trace of a firearm. ATF passed ATF ruling 2013-3 that authorizes secondary manufacturers to accept the original serial number, and other markings, on receivers they purchase with complete markings to manufacture a new firearm.

“ATF Rul. 2013- Held, pursuant to 27 CFR 478.92(a)(4)(i) and 479.102(c), ATF authorizes licensed manufacturers and licensed importers of firearms, and makers, to adopt the serial number, caliber/gauge, and/or model already identified on a firearm without seeking a marking variance, provided all of the following conditions are met.” Ensure you download and read the entire ruling.

Unlawful processes:

The GCA also makes it a felony to remove, obliterate, or alter the serial number in any manner. As established in Title 18, U.S.C., Section 922 Unlawful Acts:
(k) It shall be unlawful for any person knowingly to transport, ship, or receive, in Interstate or foreign commerce, any firearm which has had the importer’s or manufacturer’s serial number removed, obliterated, or altered, or to possess or receive any firearm which has had the importer’s or manufacturer’s serial number removed, obliterated, or altered and has, at any time, been shipped or transported in interstate or foreign commerce.

If you are working on a firearm performing gunsmithing, polishing, or some type of modification, DO NOT tamper with the serial number. There are numerous incidents in which gunsmiths have polished off or moved the serial number on a firearm for their convenience. DO NOT continue this practice. You could be charged with a violation of section 922 (k) of the GCA and your customer will lose his firearm.

With the passage of the GCA, the NFA became Title II of the GCA and regulations pertaining to serial numbers were also more firmly established as follows:
Title 26, Chapter 53, § 5842 Identification of firearms.
(a) Identification of firearms other than destructive devices. 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 Secretary may by regulations prescribe.
(b) Firearms without serial number.

Any person who possesses a firearm, other than a destructive device, which does not bear the serial number and other information required by subsection (a) of this section shall identify the firearm with a serial number assigned by the Secretary and any other information the Secretary may by regulations prescribe.

Additionally, the NFA also provides prohibited acts pertaining to serial numbers:

§ 5861 Prohibited acts.
It shall be unlawful for any person—
(g) to obliterate, remove, change, or alter the serial number or other identification of a firearm required by this chapter; or
(h) to receive or possess a firearm having the serial number or other identification
required by this chapter obliterated, removed, changed, or altered; or
(i) to receive or possess a firearm which is not identified by a serial number as required by this chapter; or …


Under the GCA licensed manufacturers and importers are required to apply a serial number and other markings on all firearms made or imported.  There is nothing in these statutes or regulations that requires an individual to apply a serial number to a firearm that is made for themselves. If you are planning to make a firearm regulated by the GCA (Title I- rifles, pistols, shotguns, etc) for personal use, it is a good practice to mark it in some manner.  It may be lost or stolen, and this way you could accurately report it to law enforcement.  Under the NFA (Title II- Short Barreled Rifles and Shotguns, Silencers, Any Other Weapons, Destructive Devices) an unlicensed person is a “maker”, and all persons to include licensees, are required to apply a unique serial number to all NFA firearms they make or manufacture.

About the Author

Mr. Vasquez was a former Marine and State Department employee for 24 years prior to joining ATF in 1999 where he was intimately involved with regulations governing firearms manufacturing, the National Firearms Act and firearms import and export policy for the past 15 years. While with ATF at FTB (where he served as a Specialist, Assistant Branch Chief and Branch Chief), Mr. Vasquez developed their Standard Operating Procedures, created firearms identification courses for law enforcement, wrote, reviewed and approved numerous firearms rulings, and provided firearms briefs for Congress. Mr. Vasquez was also instrumental in reviewing the National Firearms Act Trade and Collectors Association (NFATCA) for accuracy, and trained Customs and Border Protection (CBP) on the intricacies of importation guidelines and the recognition of unlawful imports.

This article first appeared in Small Arms Review V20N5 (June 2016)
and was posted online on April 22, 2016


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