USNAVYABH,
If it were a U S Marine, he'd just use his hands and teeth out ta 50 or so yards.
The 50 cal patched round ball will do well at 50 yards with that amount of powder. If you are worried about stopping power, you might think of using some sort of slug made by T/C or Lyman. Either way you go, best of luck in your hunt.
C F