I'm curious, what exactly do you need that much gun for?
One would have thought that anything requiring that much gun, and by that I mean Elephant, Cape Buffalo, Hippo, Tiger, Polar Bear , Kodiak or a largish Grizzly would be better handled with a rifle, or possibly a 10 or 12 gauge Shotgun loaded with Brenneks or Copper solids.
If you are dealing with large game in close quarters then one would have thought .454 Casul more than adequate, provided you load it with hard semiwadcutters.
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I don't do dumb & helpless.