Well i know you said no tag for a grizzly but if one should charge me it would be self defense and I want something that i know will do the job. I chose the .375 H&H magnum especially for this. I know the smaller calibers will take a moose but a moose doesnt have big teeth, razor sharp claws, and may want to eat you. I would seriously consider something larger than .30 caliber if you have grizzlies in the area and you dont have a back up rifle or large caliber backup pistol like the .454, .475, .480 or the .500 S&W.