I used to clean my barrels but stopped cleaning the hunting rifles.
Amazing how few on this site know how to clean a rifle but this is about the worst advice you will get, this is like saying my car still runs why change the oil or air filter run em till they quit !!!!
As to the OP, about the best and easiest copper cleaner I have found is Bore Tech Eliminator. No smell and works better than ammonia based cleaners. If you want to clean copper only they make a product called CU+2 copper remover but then you have to use a carbon cleaner also, the Eliminator does both.
