When it comes to removing copper fouling from the bore, the best product I've come across is BreakFree Foam bore cleaner. It's non-toxic and odorless and does an exceptional job of removing copper from the bore. Just spray it into the bore, let it sit for 15-20 minutes then swab out with patches until they come out clean. I have a model 10 which fouls with copper quite easily and this stuff gets it all out of the rifling.