A friend recently recomended a new foaming copper remover. "Knockout bore cleaning foam" marketed by Forrest Professional. Just gave it a try on a fouled .458 Winchester. Fired Barnes monometal solids and X bullets. IT really works and is very easy to get a bore really clean. Filled the bore up with the foam, let sit for 30 minutes and after four treatments, the bore is comming out clean. This stuff appears to really work. You guy"s may want to look for it and give it a try. I found it at a Fleet Farm locally.