I picked up an M16 BCG off arms list, the guy wanted $250 for the complete BCG and a charging handle. said he bought the part to finish his build, then when he was told he couldn't get a barrel for 2+ years, he sold all the parts off. He said that when he bought it, the guy told him it was a colt. it looks to me like a standard mil-spec BCG with chrome lined carrier and all mil-spec parts. but there are no names or numbers stamped on it. just wondered, when buying used parts, do you guys have any way of verifying who actually made it? are there any measurements I can take to confirm "mil-spec"? I'm not too concerned over it, I bought this as a stop gap for now. I have a Mil-Spec BCG on order from the same people who make Spikes' but I am tired of the indefinite waiting and lack of an honest ETA. I bought this incase I never get the BCG that I have on order, and if I do get the BCG that I have on order, I'll sell this one, hopefully for the same price that I paid for it.