Shooting a round ball requires the use of a patch, which comes in many thicknesses. I like TC pre-lubed patches in .010. TC rifles usually have a tight bore. The Lyman may shoot better with a .015-.018 patch? Wads refer to BP shot gunners where you separate the powder and shot with a wad. You should try a conical bullet also with no sabot or patch. Your Lyman is probably rifled in a slow twist for a patched round ball. It might shoot a conical ok, something like a Buffalo bullet or a TC maxi-hunter.