I have been a member of the GCA since shortly after it's inception.
I am well aware of what wears a muzzle and to believe it is from firing is pure nonsense. It is hard to believe that only M1's can wear muzzles when none of the other rifles shooting the 30-06 do. I have been the owner and operator of a Gun Shop for 30 years and I have never taken a muzzle worn out barrel off of anything but M1's. Damaged yes. Ever look at an FN49? They provide a rear port door so you can clean from the rear also it is a popular modification to the Ruger 10/22. All to protect the muzzle from cleaning rod wear.
