The 1853 is a rifle musket, not a musket. Probably three groove, shallow, and slow twist. I suspect your minies are just too hard to obturate properly, and strip the rifleing to a degree. Minie balls need to be as soft as possible (almost pure lead, or with just enough tin to cast well), otherwise the skirt doesn't expand enough to take the rifleing. Can't hurt to try a .570 patched round ball, either.