I cannot remember where I read the article but, it dealt with the amount of time a person had to shoot a charging animal. A study had been done and, it determined that in most cases, a hunter had practically no time to shoot when being charged by a bear or wild hog. The article explained, if you are not expecting the charge, even if you are carrying a rifle or shotgun, you probably won't get off a shot! This study was done assuming the hunter was in some thick cover.
Most of my hunting now is done from a stand or, at least, a fixed position. I no longer do a lot of walking in the woods but, in the past, in many instances, while stalking, I have had time to sling or set down my rifle or shotgun to take a shot with my handgun. This was always with an animal that was not aware of my presence. My favorite method of carry was with a chest rig. Seemed to be much less tiring than hip carry. Wish I wouldda learned about chest rigs years earlier!
The .357 has killed alot of game but, like everyone here, I agree it is NOT an acceptable choice for protection against black bear. Another vote here for the .44 magnum.
If you like the .45 calibers, you can buy a .454. You can practice with .45 Long Colt and still have the option of the powerful Casull cartridge for the serious stuff. Met a guy one morning after the hunt, at the local breakfast joint, who said he'd just shot a 180 pound sow end-to-end with his brand new .454!