The world record bear is a monster Polar killed by an Inuit with-- a 220 Swift.
I helped murder a Kodiak that became a danger to a local community.
The post mortim revealed old wounds holding 14 rounds ranging from .30 to .375 caliber, all poorly placed. I'd have an attitude too.
Later a butcher suffered a fatal heart attack and gently crashlanded his J 3 in a big meadow. When we arrived bears were everywhere eating black deer sausages, moose chops and caribou stew cuts. I discharged 17 of 20 .375 rounds I had ( read earlier post about private weapons supplamneting the Ithaca survival rifle) and they still ignored us. So, we waited until they were finished before moving in. I had my last 3 loaded, everybody's nervous and I'm laughing. If I had a belly full of black deer suasage why eat a stringy coastie?
After military service, I spent a season on Kenai doing bear surveys. We all checked out on the .375 H&H. More importantly, we learned how to avoid confrontations.
More bears are murdered annually than all the deaths of humans since records were kept.
In the RARE case of a bear charge the standard shot is one to the shoulder to break the charge and THEN a killing shot, or shots. For that a robust bullet of high sectional density; a 7MM 174 GR .30 220gr .357 350 gr etc. is best.
What is better, is to just be loud,obnoxious and behave like most people outdoors. Bears actually have rather high standards of who they socialise with. Drooling grizz on the cover of Outdoor Strife sell magazines, not common sense.