Quoted: In This particular display seize through the SAS vid, the pivot pin boss sure looks reprofiled to me. Both of those radii are Reduce The "C" on the barrel would point out a chrome chamber only barrel. But AFAIK, Colt marked the "C" up close to the muzzle on https://coltm16a1forsale36977.ambien-blog.com/37511262/facts-about-colt-combat-unit-rail-gun-45-revealed