OK we have dicussed several cleaners here in the past but I tried this one recently and was pleased. Does just what it says! I have been using it on my varmit rifles and it has worked great! Removes all the residue and copper fouling in 1 or 2 treatments depending on how bad the copper fouling is. Good thing is it doesn't take any effort on my part. Just stick the nozzle in and give it a squirt until foam comes out the other end. Let it sit for a while and patch it out. No brushing. Works very well! I have used it on a few auto loaders but be wary of the foam shooting out the gas system! This stuff really gets into the gas system. No smell, no amonia etc. very mild stuff.