I found multiple versions when I seemed. Some were being marked M-16A1, and some were marked M16A1. Some experienced SERIAL truly stamped on there before the serial amount, and Other individuals didn't. If I'm using a non-nfa class three reciever, could I set within a "bogus" sear pin on my https://colt-combat-elite-defende78899.wikievia.com/10108893/what_does_colt_combat_unit_rail_gun_45_mean