Got a deal I couldn't refuse and picked up one of these drums up today at a funshow. I was wonderng, well I was searching for info today on the drum and found a pic. of the box at auction arms I think and it had several, about 5 other guns that it would work in other then the AR-15. Is there any different "lips" that you could get for it so you could use the drum in other types of guns? Now I know you wouldn't want to drop t on anything hard but just how brital is the plastic? And I have no dought in my mind that it s a pre-ban mag, but if I ever needed to show proof of the manufacture date how would I do that?