Hey BP don't let the big bullets bother you any. If you lower the powder charge, they are sweet to shoot. I shoot a 550 gr. lead bullet in my Zouave with only 42 grs. of Goex ffg. Now I know this is a load normally used by the N-SSA guys in their civil war guns, but have had friends tell me that these charges are not *****cats. They will take deer sized game. I do have a friend who hunts with his Enfield 3 band .58 cal. and he only loads 60 grs. of ffg of bp.
Now as to an inline I would look for a load of 240 gr. XTP with about 70 grs. of powder, say maybe Goex Pinnacle or Pyrodex. That should work nicely pal.