when I first got to Montana (1970) I hunted elk with my 243. 105 g Speer spitzers at 3000 fps worked fine as long as the shots were inside 200 yards and broadside. When i started guiding in the Bob Marshall the outfitter made me trade up to a 270. Grizzlies were abundant then and still legal to hunt (25 tags / year). I thought the 270 was a cannon lol!