I've used Hoppe's since I got started shooting with pretty decent results, but lately I've switched over to BoreTech Eliminator. Made the switch for several reasons, it has no ammonia. Ammonia scares me, and that is the primary copper cleaner in Hoppe's. No ammonia also means no or very little smell. People around the house now don't even comment on smell until I open up the gun oil. Boretech also cleans 10X faster than hoppe's, it takes maybe 10 mins of soaking to clean out the copper. I agree with the posts above though, a little copper left in the bore is not necessarily a bad thing. Its just filling in some imperfections. Be careful not to over clean either, cleaning is not a benine process.