You can scrub with wire brushes and solvents on the face of a stainless revolver and not remove the marks but rub an ADCO E-Z Brite Cloth on the same area and watch it disappear. Carbon and lead wipe right off. It romoves rust too, so be careful not to use it on some blued guns. Bluing is a rusting process and you won't want to remove that. However many people use these on blued, handguns, rifles and shotguns to clean the bore. Do you want to remove lead or brass; even plastic in front of a shotgun chamber. Push a small patch of the E-Z Brite down the bore with a brush and watch the build up come out.