We can all discuss stopping power and most will agree that it is a relative quantity that increases with the size and velocity of projectiles.

If we talk real world we all know that nothing is guaranteed and that an attacking or adrenalized animal makes all this inductive calculation irrevelant.

Then as one poster puts in his post signature, your options have become wonderfully simplified--either you kill/stop the attacking beast or someone will be writing your epitaph!!

I would certainly hope that mine would never be-"Couldn't hit the stopper and didn't use enough gun!!"