I had a friend who professionally restored antique arms and swords etc. and he used a lot of stainless steel scotch-brite (in the kitchen section) with any light petroleum distillate, for instance kerosene, for the tougher jobs. It looks too aggressive, the steel in the pad appears to be lathe swarf or drill press shavings, but it really works fast without damage...used sensibly. He specialized in removing rust, but leaving patina. Very effective on old muzzle loader bores. You may have seen some of his work, pieces that went from the Harold Pappy Smith collection to Cody and elsewhere.
Last edited by flintlocke; 09/15/21.
