Just ask the bears
Well since I live in Alaska, and some people just seem to want to continue on and on and on with never ending bear threads:
Forget the dogs, someone would have to get past the really grouchy, really big, really hungry bears that are just beginning to think about coming out of hibernation really soon!
And as bears are not true hibernators, even during the dead of Winter, "Are you feeling lucky..."
And as true believers in, "Supporting your right to arm bears" the bears around here are a bit more dangerous; they tend to use whatever smaller caliber handguns that they "pick up" on the trail.
So to get a straight answer to the OPs question, I would direct you to the neighborhood watch bears outside my door. By the looks of the threads here, I would guess a bunch of .357s and 9mm, with the occasional .45 and .40.
(And you were wondering where all of the ammo went! Now you know. Lotta bears in Alaska and they all stocked up before hibernation; and here you thought that it was a political thing.)