ATF Ruling 1981-4 — Auto Sear Classification

27 CFR 179.11: MEANING OF TERMS The AR15 auto sear is a machinegun as defined by 26 U.S.C. 5845(b). ATF Rul. 81-4 [Status of ruling: Active] The Bureau of Alcohol, Tobacco and Firearms has examined an auto sear known by various trade names including “AR15 Auto Sear,” “Drop In Auto Sear,” and “Auto Sear II,” which consists of a sear mounting body, sear, return spring, and pivot pin. The Bureau finds that the single addition of this auto sear to certain AR15 type semiautomatic rifles, manufactured with M16 internal components already installed, will convert such rifles into machineguns. The National Firearms Act, 26 U.S.C. 5845(b), defines “machinegun” to include any combination of parts designed and intended for use in converting a weapon to shoot automatically more than one shot, without manual reloading, by a single function of the trigger. HELD: The auto sear known by various trade names including “AR15 Auto Sear,” “Drop In Auto Sear,” and “Auto Sear II,” is a combination of parts designed and intended for use in converting a weapon to shoot automatically more than one shot, without manual reloading, by a single function of the trigger. Consequently, the auto sear is a machinegun as defined by 26 U.S.C. 5845(b). With respect to the machinegun classification of the auto sear under the National Firearms Act, pursuant to 26 U.S.C. 7805(b), this ruling will not be applied to auto sears manufactured before November 1, 1981. Accordingly, auto sears manufactured on or after November 1, 1981, will be subject to all the provisions of the National Firearms Act and 27 C.F.R. Part 179. Editor's Note: Regardless of the date of manufacture of a drop in auto sear (i.e., before or after November 1, 1981) the possession or transfer of an unregistered drop in auto sear (a machinegun as defined) is prohibited by the National Firearms Act (NFA), 26 U.S.C. § 5861, and the Gun Control Act, 18 U.S.C. § 922(o). The last paragraph of ATF Ruling 81-4 only exempts the making, transfer, and special (occupational) taxes imposed by the NFA with respect to the making, manufacture, or transfer of drop in auto sears prior to November 1, 1981. See 26 U.S.C. §§ 5801, 5811, 5821, 7805(b)(8).