RE: Tips for cleaning an old rifle (no knowledge about prior upkeep)
NOSTAINLESS BORE BRUSHES!!!! Stick to Bronze or nylon. Personally I'd strip it down, start with your normal solvent &thensweets for Copper. It very well mayneedto be fouled if pitted but leaving it longer will nothelp things either. You may need to use JB's,etc but I'd try cleaning it like you normally would your rifles first,then shoot it to see how it does.