Re: Need help choosing a side arm
Personally, i feel comfortable working or playing in griz country with my Ruger Super Blackhawk .44 mag with 340gr hard cast lead bullets at 1450fps by Buffalo Bore, or the Ruger .45 Colt i used to have and loaded hot was even better.
However i would feel the the .45 ACP with ball ammo, or HC lead (NO HPs!!!) will do the job just fine. I have seen plenty of cattle put down with a 1911, and don't think a bear has a much thicker skull plate than an old range bull. Anything that happens will be up close and require a good solid CNS hit to stop the fight. I would carry what you are used to, and then not be left with a gun that is not very practical for anything besides bear duty. You also might consider bear spray, alot of us here carry it and the numbers don't lie: 90% effective at stoppping an attack without harm whereas guns are only 50% effective per the USFWS data. A thin thread to hang from!
Also i have to doubt any grizzly in the Lower 48 will go a half a ton, the largest bear ever weighed by the Fish, Wildlife, and Parks not far from a ranch I used to work on weighed right at 800 lbs, it is far more common to see them in the 350-400lb range.
Good luck on your hunt!