rounds. (F) A semiautomatic shotgun that has any one of the following: (i) A folding or detachable stock. (ii) A pistol grip. (iii) A fixed ammunition feeding device with the capacity to accept more than 5 rounds. (iv) The ability to accept a detachable ammunition feeding device. (v) A forward grip. (vi) A functional grenade launcher. (G) Any shotgun with a revolving cylinder. (H) Any belt-fed semiautomatic firearm. (I) Any combination of parts from which a firearm described in subparagraph (A), (B), (C), (D), (E), (F), (G), or (H) can be assembled. (J) The frame or receiver of a rifle or shotgun described in subparagraph (A), (B), (C), (F), (G), or (H). (41) The term barrel shroud — (A) means a shroud that is attached to, or partially or completely encircles, the barrel of a firearm so that the shroud protects the user of the firearm from heat generated by the barrel