(mm is more potent than many think - at close range it can go through a couple human bodies and still have enough to kill a 3rd if it isn’t a hollow point. For a bear I would rather have my 357 with hollow points though - penetrate and lacerate....
Were I in bear country, I think I would be packing my Glock 21 in .460 Rowland or a Glock 20 in 10mm. These things happen so close and so fast that I think I could get more lead into the bear faster than with a .44 magnum revolver of any kind. Looks like 230 grain hardball would be the way to go.
I would rather use semi-jacketed soft points in wheel guns or FMJ in auto loaders. Penetration is preferable to expansion for heavy bears. I shot a 300# boar sideways behind the shoulder with hot 240 gr SJSP .44 loads and they did not exit. The bear took a few minutes to settle down.