I was just wondering if anyone had experience with this. I bought a bottle today. The man said that it would break impurities loose from the barrel & that over time it would build up to where copper, powder residue, lead etc. wouldn't build up on it. I had asked him about what he had that would break lead loose. I have an old Dan Wesson 15-2 that has a lot of lead build up in the barrel from before I got it. I have used up huge amounts of patch cloth-a bottle of Remington 40 X bore cleaner & 3 bronze brushes & it's still there. I am going to try this if anyone has experience with the Hoppes Elite or anything else that would work please post it.