Thanks for all the replies!
Pitting wins it I think...
Acetone, Copper Solvent, MEK, a light rubbing with JB, nothing will touch it.
It's pretty rough when you run a patch over it.
I'm guessing by the wisdom here, that it won't hurt the accuracy too much. I wonder if it'll copper foul faster? That was another good thing about this barrel, it would shoot and shoot and shoot without fouling. I guess we'll see. Unfortunately, it'll be a little while before I can shoot it again.
Maybe I didn't trash it!
I did run the borescope down my Weatherby 270Win that'll shoot 1/2" @100 all day long, and man does it look like a hack job compared to the Cooper! I ran it down my Feddersen 22LR too, and the 452 CZ. They'll all shoot lights out, but none of them are as pretty as this one... Maybe she'll still shoot, and not foul up too bad.
Now the borescope is going into the cupboard. No sense in worrying over something I can't fix at this point. I'll let the targets and the patches tell me what she's doing now.
Thanks Guys