When I hunt elk and moose in grizzly country,I carry a 300ultramag loaded with the 180gr tsx.I have no doubts whatsoever that this combination is more thanadequate for killing any grizzly that walks.The grizzly that I did kill,was killed with a 338x8mmremmag when it charged me.At 40 yards the bullet stopped the bear in it's tracks when it struck the bear in the throat and travelled lengthwise through the bear.That being said,I actually feel more confident carrying the 300ultramag,as the tsx bullet offers even better performance on game than the partition that I used to kill the grizzly.