I think part of the confusion with these threads is that people sometimes think of two completely different situations.
1. Can you use that .357 you own to hunt the (blank) bear, or should you get another gun to realistically and ethically handle the job?
2. Can you use that .357 you own to save your life if you are attacked by a (blank) bear, or should you get another gun to go in those areas where there are bears?
I am not a hunter, but from the safety of my armchair I believe that I would answer Question 1 with a "no". I would answer Question 2 with: "If you have a .357 and you are experienced and comfortable with it, then it is a better choice for you than a new gun that you are not used to, or possibly can't fire quickly."