My goal with my build should be to A) Have a very historic gun with very good roll marks, B) Not commit "Colt Funds" around the challenge. Indeed, I'm certain the upper receiver is Colt, together with the BCG. It is admittedly the barrel that is definitely questionable to me. https://colt-m16a1-for-sale57897.bligblogging.com/31777838/the-basic-principles-of-colt-combat-elite-commander-45-acp