COLT M16A1 FOR SALE THINGS TO KNOW BEFORE YOU BUY

I found numerous variants Once i appeared. Some ended up marked M-16A1, and several had been marked M16A1. Some experienced SERIAL in fact stamped on there before the serial quantity, and Other individuals didn't.Sure, I'm absolutely sure the higher receiver is Colt, combined with the BCG.  It is basically the barrel that's questionable to me.It i