I ruined a couple antique SXS shotguns shooting subs in them. That stuff is incredibly corrosive. I was given some of it for free and decided to use it up in shotguns. Never again. Both guns had lightly pitted bores. Even with proper cleaning the subs will get in those pits and eat up old barrels. They are both so pitted now I'm afraid to shoot them. Might have well poured acid down the barrels.