I normally use Shooters Choice Copper Cleaner , for rifles and hand guns . It smells of ammonia , which really does well cleaning copper . It also cleans carbon . I can use hoppies #9 to clean a barrel , then switch to Shooters Choice & it will remove more " stuff " . After I am through , I go back to hoppies to : kill " the ammonia , then oil . In cold weather , automatic transmission fluid seems to make a good lube . In hot weather , 5W-30 synthetic motor oil seems to work well .