You are at the foot of the Sierras, so I presume we are talking black bears and/or perhaps hogs? (I got attacked by a deer once, in my local mountains (San Bernardinos). Luckily, I was in full motocross gear including helmet, so it was indeed a fair fight!)

Required reading (JJHack posts): Model 29 Mountain - Topic

A 180 gr cast is fine for 'hunting', where you are going to stalk your unsuspecting prey up close and pick your shot placement carefully, but in reality all it does is punch a tiny little hole that is about as effective as an arrow, unless you get a good CNS shot or happen to hit major circulatory system components. The animal will take a while to die, and hopefully you will have a blood trail to follow to the carcass....

'Defensive' shooting on dangerous game is however a completely different matter! Shot placement will be whatever you can get in your sights quickly and under stress, so your chances of a good CNS or circulatory system shot will be more luck than anything else. Here, you want to be able to break bones if possible, but you also want to do lots of tissue damage as well. I like Hornady 158 gr XTP, but only if the barrel is at least 4" long. These are tough bullets and will penetrate well, but they will also expand and do extensive tissue damage and therefore create blood pressure loss.

Got to say that for years I carried a .357 in black bear country, and felt reasonably well armed. But recently, reason prevailed and I came to my senses and switched to .44! Lots of great, light guns these days! I carry the 329NG for hiking/backpacking, and the Ruger Alaskan when car camping where weight isn't an issue. If you feel you need a 4" barrel, then the 329PD should fit the bill if you want to travel light.

The .357 is still my 1st choice down in the lowlands, where cats are the largest threat. (Had to deal with a nasty bobcat once, and that was NOT a fair fight!)