I agree with the rest, clean out any copper that shows up after each use of the rifle................otherwise, you'll just be multiplying your cleaning effort later on.

I like Sweets 7.62 or Barnes CR-10 for copper removal - both do an excellent job. I've also begun to like the Outers Bore Foam sold at WalMart. Letting a squirt of that sit in the bore for 30 minutes tends to remove ALL traces of copper from my rifles.................However, it really does a poor job on carbon fouling though - so it's a mixed bag. One word of warning about using the bore foams......................don't use them in gas operated semi-auto firearms (unless you can close off the gas system from the bore) - otherwise the operating sytem will get gummed up pretty badly.