Muddydog,
three years ago my logging boss was in AK laying out roads. He and his partner had their heads up their asses b/c my boss took a Ruger 9mm with 147gr JHPs for protection. His partner had a double barrel 12 ga broken down in his pack. To make a long story short, they got charged by a female brown with cubs right after getting dumped off by the Hughes 500.
My bosses partner got mauled, but not critically. My boss went back and hosed the bear with the Ruger. Bear was not killed but ended attack.
Again, the pistol did not kill the bear, but the attack ended. My boss returned to Oregon and immediately bought a .45-70 carbine.
Not recommending a pistol for bear either, but I like them better than my numchucks.
USFS training up here recommends .375 HH or Brenekke slugs.
.30-06 is a documented bear killer, so .308 will do the job, but bigger is better.