how can i tell if the gun is a pre or post ban. it is a car with no colapsable stock. the thing that throws me off is the . well looks like a flesh supresor on the end of the barrel. it is about four inches long.and it has a few little holes in it in the sides.it has the a2 sights. and the forward asst.i don't see any bayo lug though. so it there a way with the numbers on the side.