There is no handgun or handgun load that will reliably stop a large bear.
If you absolutely must shoot a bear with something smaller than field artillery or a close air support aircraft, I would recommend a 12 gauge shotgun loaded with slugs. But it's better to avoid the bears.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.