As has already been stated, I would favor solids that maximize penetration and internal damage. You aren't going to knock a bear off their feet with a 357, so all you can hope for is causing massive internal damage that bleeds the bear out quickly. I would drive it as hard as possible, but obviously you have to stay within he load limits for revolvers.
Hornady makes a 357 spire point specifically for hunting handguns. I used to use it in my 357 Remington Maximum. It's like a 158 grain or something like that. That's where I'd start.
Compared to rifles, no handgun is really adequate for bears, but with that said the 357 is certainly better than nothing.
Grouse