I am having fun with my Ruger M77 in 30-06. Not a muzzleloader butmy problem relates tothesubject matter. I bought it in 1984 and fired less than 100 rounds through it since. I had it out the other day and the groups are getting progressivley worse. Upon closer inspection I have a severe copper fouling build up. I have always cleaned my rifles with Hoppes #9 which does not address copper fouling. I picked up some Hoppes Benchrest amd let it sit overnight and cleaned the next morning. I have repeated this process several times and still pulling out CU. I think I am going to get some Sweets or Butches Bore Shine to speed up the process.