[Spktyr]

I've heard of .357 Mag just bouncing off of some bears' skulls. Give me a .44 Mag, .45 ACP, or something bigger.

[The Grammarian]

A lot of calibers just bounce off grizzly skulls. .44 Magnum or .50 AE (which IS a Magnum round, I believe; I think it's .50 Magnum redesigned for an autopistol) are both better at penetrating the grizzly's skull than the .45 ACP or .45 GAP, but you still have to watch out for the skull deflecting some shots.

[JasonC]

.357 magnum has far more muzzle energy and penetration than 45 ACP. A .44 mag is better sure. A 45 is only going to equal a .357 if you load +P ammo. As for where to shoot, center of mass. Heart or lung hits will stop them, lung hits being the most common effective hits. A 30-06 is better than any pistol of course, and is what you'd use if you were being deliberate about it.

As for the story, they are both lucky to be alive, and the girl did exactly the wrong thing. You are much better off fighting like the dickens than lying still and hoping they will go away. If you aren't armed and are attacked, throw things (pain caused from farther away is much more likely to trigger "flight"), and hit it on the nose or in the eyes with a club if it gets close.