imported post
If I was to carry a pistol; It would the .44 Superblack Hawk stoked with 300gr or heavier hard cast hand loads.
With that said, if I was truely concerned about 4 legged critters (especially Bear or Mountain Lion) the nod would go to a rifle. A lever action 45-70 stoked with stout hard cast 405 gr or 420 gr bullets is short, light and has more power than any pistol out there. You'll also get off more acurate shots than a pistol. Hard cast bullets will give more penetration than jacketed HP's or Soft Points, and in the kind of situation you are concerned about, you'll want to drive a heavy bullet end to end if possiable, as many times as you can in the split seconds available.
Just my opinion because I have a .457 mag in the 1895 Marlin and have shot most of the pistol and revolver rounds cited in the thread.
Steve