I hunt in grizzly country and recreate in grizzly country as it is all around us.
Use what ever cartridge / bullet combo is appropriate to the primary game hunted.
Defending ones self in a bear attack is much different than you may think.
When hiking/hunting one must use his/her nose, this will alert you to a cache, the folks who have been mauled and killed many times stumbled onto a cache with the bear near by black or grizzly makes no matter as a B-bear will make a mess of you.
An attack generally comes on very quick and most of the time you have no option of defense other than rolling into a ball and protect your head neck area as much as possible. And at some point your must fight in the physical sense if the attack is doing you in. Grizz play dead they will bury you , must like fermented hunter. B-bear will just f'ing kill you.
If one does have an opportunity to employ a rifle, the shot should be really close, if ya got the balls for that, as the outcome most likely be better.
As far as stopping power (a hunting situation, not a defense situation) goes that starts at caliber 33. I have detected no real difference in terminal performance on bullets between 225 grains and 270 grains in 33,35,36,and 37 caliber, running 2500-2700 ft/s at the muzzle.
