So I have this m91/30 ex-pem sniper. Thought I got a great deal on it until I took a closer look at the bore. What I had thought was just some kind of debris I could wipe away is actually these massive pits? Tool marks? Pitted tool marks? Which have a bunch of copper fouling on the muzzle end edges. Two tool marks about 4-5 inches into the barrel. What do y'all think are my options here? Do I bother cleaning the fouling out and shooting it, and just monitor the amount of buildup? Or is this barrel a gonner? I have never encountered something like this before.