My target with my Create would be to A) Possess a historic gun with very good roll marks, B) Not devote "Colt Cash" about the project. The "C" within the barrel would indicate a chrome chamber only barrel. But AFAIK, Colt marked the "C" up near the muzzle on their https://coltcombatunitrailgun4555555.national-wiki.com/1069009/indicators_on_colt_m16a1_for_sale_you_should_know