I carry a Taurus Tracker TI in 41 mag for bear defense when I’m in the Rockies. I also have the equivalent in both .45LC and 44mag.
They are very handy, light, five shot four inch revolvers. I also carry them for daily carry quite frequently.
The 10mm in a semi auto is also a very good choice although considerably heavier.
I shoot both the 10mm and .41mag on large wild boar quite frequently and they are about as heavily muscled and densely bodied as all but the largest of bears and extremely difficult to bring down quickly absent a direct hit to the central nervous system. Anything that works well on large boars you should find very effective in bear defense for all but the very largest of bears.
If I lived in Grizzly country my go to defense would be a 12g with slugs or one of my M1A’s.