I have not shot any grizzly with my Whelen, but I have shot a couple of black bears and one moose (at 410 yds). I prefer the 225 gr. bullet for the Whelen for general use, but would go with the 250 for brown/griz if it were me. My handloads can usually get a easy 2500 fps with most any 250 gr. bullet, which is plenty, in my experience.