I have not killed any bear in years, but when I used to hunt them I used a 44 magnum most times. I used both 265 gr Hornady bullets and later 320 gr LBT Cast bullets on them. Both bullets works very well, but the LBT was better in that it always exited the bear and I had 2 of the 265 gr bullets stay in them. I like a through and through wound.
All in all I killed seven with my 44 mag revolvers. 6 with my S&W and 1 with a Ruger Redhawk.
I also killed a three with my 270 with 150 gr Nosler Partitions, one with a 45-70 with a 400 Gr RCBS cast bullet, and two with a 375 H&H with 270 gr Winchester Power points. (It’s what I had handy at the time)
I think that's all of them. I can't remember any others.