Not a bad choice at all.
I have hunted grizzly country in Montana with a .270 in my hands (or a .280, which is indeed the same thing) and haven't felt particularly nervous. 180 Woodleighs in the .270 or .280 would be an option, but I have generally had 150 Partitions in the rifle.
While maybe not ideal as big bear stopper I certainly wouldn't throw the 270 down and run
