On that...we've seen '94 Winchester rifles with almost nothing left shoot fine with jackets and Lee Enfields too. I've shot M1rifles that had little left but jackets shot OK as long as not pushed too hard. It's hard to tell without shooting them. Now it's replaced though, it should be good. I had a Krag rifle with a dark bore shot fine but pattern 24" to eleven on the clock. Turned out it had a ring within an inch of the muzzle that was oblong, thus throwing the bullets. It still grouped fine, just off to eleven...