Handguns are weak and tiny for big bears...
Handguns are more difficult to hit with. A proper hardcast LBT or Keith style SWC with a sectional density of .270 at 1200-1300fps will break bones and fully penetrate virtually any brown bear from virtually any angle. Ross Seyfried proved their effectiveness against Cape buffalo, with 360gr .45's penetrating four feet of hide, heavy bone and muscle. A much larger critter than any brown bear. You can't ask for more than that, unless you worship energy. In which case, only a .470NE will do.