James B your right a .378 WBY. might be on the light side. Better off using a .460 WBY, or a .470 Double, or even better yet the .50 BMG should work great! lol Seriously I think a .7mm-08 will work for elk. I myself like the .300 Mag's, but not everyone can shoot them. If you are willing to wait for the right angle or strait broadside shot, then out to 250 yards will work great with a premium 160 gr. bullet.