I've RIA drawings specifing barrel markings on a completely new USGI rifle Which marking will not be licensed. Unfortunately, I am on journey so I am unable to article pictures in the bolt. It really is MPC engraved. The only real marking over the carrier would be the "C" stamp https://coltcombatelitecommander470011.wikigop.com/975468/colt_m16a1_for_sale_fundamentals_explained