Barnes CR-10 and Sweets 7.62 are both top notch copper removers. Just make sure you use plastic brushes and jags with them because they will attack brass just like they do copper, so you'll get false readings of "blue" patches from the brush/jag.
For powder fouling, I've been using MPro7 (same as the new Hoppes Elite cleaner) for a couple years now & I REALLY like how it works. It'll take out everything BUT copper in fairly short order and it doesn't smell like someone's underarms. [:'(] I'll clean the bore with it and then go after the copper with CR-10 or Sweets. After patching that out, I'll run a couple more patches of Mpro to verify cleanliness (and to neutralize any of the ammonia in the copper cleaner), patch dry and apply oil (currently using FP-10). MPro WILL take all the oils out of the metal, so you have to oil well following it's use.