ATF

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Bureau of Alcohol, Tobacco, Firearms and Explosives

Is it legal to assemble a firearm from commercially available parts kits that can be purchased via internet or shotgun news?

For your information, per provisions of the Gun Control Act (GCA) of 1968, 18 U.S.C. Chapter 44, an unlicensed individual may make a “firearm” as defined in the GCA for his own personal use, but not for sale or distribution.

The GCA, 18 U.S.C. § 921(a)(3), defines the term “firearm” to include the following:

… (A) any weapon (including a starter gun) which will or is designed to or may be readily 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 silencer; or (D) any destructive device. Such term does not include an antique firearm.

In addition, the National Firearms Act (NFA), 26 U.S.C. § 5845(b), defines the term “machinegun” as:

… any 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. This term shall also include the frame or receiver of any such weapon, any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun, and any combination of parts from which a machinegun can be assembled if such parts are in the possession or under the control of a person.

Finally, the GCA, 18 U.S.C. § 922(r), specifically states the following:

It shall be unlawful for any person to assemble from imported parts any semiautomatic rifle or any shotgun which is identical to any rifle or shotgun prohibited from importation under the…[GCA]…Section 925(d)(3).as not being particularly suitable for or readily adaptable to sporting purposes ….

Also, 27 C.F.R. § 478.39 states:

  1. (a) No person shall assemble a semiautomatic rifle or any shotgun using more than 10 of the imported parts listed in paragraph (c) of this section if the assembled firearm is prohibited from importation under section 925(d)(3) as not being particularly suitable for or readily adaptable to sporting purposes ….
  2. (b) The provisions of this section shall not apply to:
    1. (1) The assembly of such rifle or shotgun for sale or distribution by a licensed manufacturer to the United States or any department or agency thereof or to any State or any department, agency, or political subdivision thereof; or (2) The assembly of such rifle or shotgun for the purposes of testing or experimentation authorized by the Director under the provisions of [§478.151(formerly 178.151)]; or (3) The repair of any rifle or shotgun which had been imported into or assembled in the United States prior to November 30, 1990, or the replacement of any part of such firearm.
  3. (c) For purposes of this section, the term imported parts [tabulated below] are:
    1. (1) Frames, receivers, receiver castings, forgings, or castings.
    2. (2) Barrels.
    3. (3) Barrel extensions.
    4. (4) Mounting blocks (trunnions).
    5. (5) Muzzle attachments.
    6. (6) Bolts.
    7. (7) Bolt carriers.
    8. (8) Operating rods.
    9. (9) Gas pistons.
    10. (10) Trigger housings.
    11. (11) Triggers.
    12. (12) Hammers.
    13. (13) Sears.
    14. (14) Disconnectors.
    15. (15) Buttstocks.
    16. (16) Pistol grips.
    17. (17) Forearms, handguards.
    18. (18) Magazine bodies.
    19. (19) Followers.
    20. (20) Floor plates.

As a result of a 1989 study by the U.S. Treasury Department regarding the importability of certain firearms, an import ban was placed on military-style firearms. This ban included not only military-type firearms, but also extended to firearms with certain features that were considered to be “nonsporting.”

Among such nonsporting features were the ability to accept a detachable magazine; folding/telescoping stocks; separate pistol grips; and the ability to accept a bayonet, flash suppressors, bipods, grenade launchers, and night sights.

Please note that the foreign parts kits that are sold through commercial means are usually cut up machineguns, such as Russian AK-47 types, British Sten types, etc. Generally, an acceptable semiautomatic copy of a machinegun is one that has been significantly redesigned. The receiver must be incapable of accepting the original fire-control components that are designed to permit full automatic fire. The method of operation should employ a closed-bolt firing design that incorporates an inertia-type firing pin within the bolt assembly.

Further, an acceptably redesigned semiautomatic copy of nonsporting firearm must be limited to using less than 10 of the imported parts listed in 27 CFR § 478.39(c). Otherwise, it is considered to be assembled into a nonsporting configuration per the provisions of 18 U.S.C. 925(d)(3) and is thus a violation of § 922(r).

Individuals manufacturing sporting-type firearms for their own use need not hold Federal Firearms Licenses (FFLs). However, we suggest that the manufacturer at least identify the firearm with a serial number as a safeguard in the event that the firearm is lost or stolen. Also, the firearm should be identified as required in 27 CFR 478.92 if it is sold or otherwise lawfully transferred in the future.


Q: Are Glock conversion devices legal?

A Glock conversion switch is a part designed and intended for use in converting a semiautomatic Glock pistol into a machinegun; therefore, it is a “machinegun” as defined in 26 U.S.C. 5845(b). Glock conversion devices are considered post-May 19, 1986 machineguns and may only be lawfully possessed by properly licensed Federal Firearms Licensees who have paid the appropriate Special Occupational Tax (SOT) required of those manufacturing, importing, or dealing in National Firearms Act (NFA) firearms.

Conversion is fast and simple requiring no technical expertise. Conversion requires removal of the original polymer slide cover plate and replacing it with the conversion device, typically made of metal. By switching these plates, which takes less than 60 seconds, the conversion is complete. Conversion of a Glock pistol will result in a rate of fire of approximately 1200 rounds per minute.

Glock conversion deviceGlock conversion device being installed

We are aware of other variations of this conversion device. We are also aware that these devices are available from certain internet sources.

Second variation of Glock conversion deviceSecond variation of Glock conversion device being installedThird variation of Glock conversion deviceThird variation of Glock conversion device being installed