I have found that no chemical truly takes out all of the coper and the only way to get it all out is that reverse electro plating thing. I think it is called foul out or something. You plug the bottom of the barrel, fill the barrel with a provided solution and then insert the rod (plug it in) and wait a couple of hours. The rod will attract all of the copper and the barrel will e clean. Unless your a competition shooter or a rapid firing sort of dude, dont sweat it too much. You will always have some copper in your barrel. It aint exactly benificial, but a little wont destroy your barrel or render your rifle useless. The kit is about 120 bucks. Once I find the name of it, I'll post it here. EJ