If you want the bear to stop or be incapacitated at the shot, you have to take out the central nerous system, i.e. brain or spine. Shots that will be fatal eventually really aren't much good, as a "dead" bear can be very dangerous.
The reason I say the 357 is up to the task, is only a CNS shot will stop a charging bear, and a heavy hardcast from a .357 will reach the brain or spine just as effectively as a 44, 45, 475 or 500. None of those more powerful handgun rounds placed somewhere are going to stop a bear, they also need to hit the cns.
For hunting, you aren't limited to a cns shot, hence the .357 isn't the best choice.
As a conversation with a former co-worker who sought advice about a bear defense handgun went. Him, what type of handgun do you recomend for bear defense? Me, are you an expert shot with a handgun? Him, no. Me, do you plan to put in the practice to become one? Him, no. Then a handgun will be useless to you, get some pepper spray and don't be stupid in the woods.
