26 U.S.C. § 5685: Penalty and forfeiture relating to possession of devices for emitting gas, smoke, etc., explosives and firearms, when violating liquor laws

Whoever, when violating any law of the United States, or of any possession of the United States, or of the District of Columbia, in regard to the manufacture, taxation, or transportation of or traffic in distilled spirits, wines, or beer, or when aiding in any such violation, has in his possession or in his control any device capable of causing emission of gas, smoke, or fumes, and which may be used for the purpose of hindering, delaying, or preventing pursuit or capture, any explosive, or any firearm (as defined in section 5845), except a machine gun, or a shotgun having a barrel or barrels less than 18 inches in length, or a rifle having a barrel or barrels less than 16 inches in length, shall be fined not more than $5,000, or imprisoned not more than 10 years, or both, and all persons engaged in any such violation or in aiding in any such violation shall be held to be in possession or control of such device, firearm, or explosive. Whoever, when violating any such law, has in his possession or in his control a machine gun, or any shotgun having a barrel or barrels less than 18 inches in length, or a rifle having a barrel or barrels less than 16 inches in length, shall be imprisoned not more than 20 years; and all persons engaged in any such violation or in aiding in any such violation shall be held to be in possession and control of such machine gun, shotgun, or rifle. Every such firearm or device for emitting gas, smoke, or fumes, and every such explosive, machine gun, shotgun, or rifle, in the possession or control of any person when violating any such law, shall be seized and shall be forfeited and disposed of in the manner provided by section 5872. As used in this section the term “machine gun” means a machine gun as defined in section 5845(b).