A Lot of rifles have been rebuilt, Specially Vietnam period rifles. Ordinarily the barrels were being replaced. Some examples of markings found on replacment barrels include: I knew Once i initially noticed it inside the rack it had been a little something 'Unique'. It can be in incredibly awesome form https://coltm16a1forsale80111.blogdiloz.com/30534779/colt-m16a1-for-sale-things-to-know-before-you-buy