Interesting Compare Contrast for this both happened in AK and both involved interior Grizz
1) 60 year old woman shot a Grizz that was tearing up her place in the bush with a .32 one shot kill, hit dead in the eye.
2) 3 experienced hunters charged from about 90 yards, all carrying 338 Win Mags all got 2 shots on target bear fell dead 10 feet from them. Damn good and accurate shooting.
Proving, nothing, #1 was lucky, #2 was lucky, you pays your money and takes your chance, in Bear country paying attention is gonna save your ass before pepper spray, or any kind of projectiles, you can smell and hear bear from quite a distance. Make noise generally they'll leave, if not, well then you can prepare to deploy pepper spray or firearms. If you don't know where they are you probably shouldn't be there, and you probably wouldn't be able to kill the bear with a tac-nuke
Personally bear defense wise I carry a 870 with OO buck and Brenneke Slugs, and spray, and a 40S&W for self defense against any 2 legged predators. Hunting 338 Win Mag for Grizz, or 30-06 180 gr SP interlock loaded to 3000 fps if I come across one that isn't specific quarry but I've got a good shot placement but only if my rifle's packing those rounds (which it frequently isn't unless I'm gunning for moose).