I use an 1894c and a S&W 686. I recently bought some 158 grain hard cast swc (Hunters Supply) off MidwayUSA.com. Several reloading sites indicate that lead bullets ought be kept below 900 fps, in order to avoid leading the barrel. I applied this loading rule when I loaded a light 158 grain LRN (not hard cast). Does this advice also apply to the hard cast lead bullets ?