Heavy handguns are not carried to stop charging bears. The hand gun a .44 Mag or .45 Mag. etc. is your last resort. I have had two friends survive Grzz attacks.
They both lost their rifles during the first hit of the surprise attack which was likened to a car crash. In one case during the final bear hug and head crush the victim was able to fire 6 rounds into the bear. A well secured handgun can survive your being tossed around for 30 minutes. Every survivor I have known never went with out a handgun.
No State Troopers here do not respond to Grissly Bears. We have Game and Fish Officers who do those duties. And they are ranging very far from the Yellowstone.
It is not just hunters that are attacked.