I have a Colt Sporter Match Hbar and the lower is marked CAL .223 but the barrel is stamped C MP(formed as one letter) 5.56 NATO 1/7 HBAR. So is the chamber reamed for the 5.56 NATO as stamped on the barrel? The box is marked .223 Rem.(5.56 MM) Model R6601. Thanks for your responses to help clarify this question.
I have been told that .223 is OK 5.56 and not vice versa. I read data that showed firing 5.56 in a .223 chamber went above specified pressure of the .223 Rem. specifications above 60,000psi.
I have been told that .223 is OK 5.56 and not vice versa. I read data that showed firing 5.56 in a .223 chamber went above specified pressure of the .223 Rem. specifications above 60,000psi.