First off, if you are in the lower 48 and not in Grizzly country you are as well served with a stout .357/10mm or .45 as anything larger. Most animals will be running from you anyway. I find the really big Magnums (.454/.50 etc) to fall into the law of diminishing returns. They aren't necessarily pleasant to shoot and most folks can shoot smaller and lighter weapons faster and more accurately with no real effective loss in protective ability. These aren't tanks, they're thin-skinned animals in the 300 pound range. Think of them as big, tough people. As far as the Appalachian Conservancy recommendations, they are all wet. Remember most hiking groups fall into the "hunting bad"/"guns evil" group. Most of them have no clue of the applicable state laws. Think of them as Handgun Control Inc. / Brady Campaign dressed in Polarfleece. Look at the actual State laws for each area and figure out what kind of Federal land you'll be on. Make sure you can effectively shoot the weapon you have and don't worry so much about caliber/power. All the mega-Magnum power in the world is useless if you can't hit what you aim at under stress and quickly.