Hot loaded 10mm or 357 magnum would be ok but I would go with a 44 mag minimum. For a semiauto I think a 50AE.
Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull.
all 25 of my guns are 45/70 govt, 357 mag, 22 or 12 ga... I believe in keeping it simple