THE 2-MINUTE RULE FOR COLT COMBAT UNIT RAIL GUN 45

Been faraway from the board for some time because of relationship, household renovations and an previous car resto, but I am now acquiring again into firearms and specially the AR15 variety. So I guess that makes me an previous semi FNG.If I'm using a non-nfa class three reciever, could I put inside a "faux" sear pin on my retro Construct or would