THE 2-MINUTE RULE FOR GOLD CUP TROPHY COLT 45

I found various variations Once i looked. Some were being marked M-16A1, and several were marked M16A1. Some had SERIAL essentially stamped on there prior to the serial number, and Other people didn't.    The "C" within the barrel would point out a chrome chamber only barrel. But AFAIK, Colt marked the "C" up near the muzzle on their own early ba