I've shot several "deer-sized" animals (including deer of more than one species) at between 300 and 400 yards with the 7x57 and various bullets from 140-160 grains. It always worked, but killed quicker with softer bullets like the Ballistic Tip and Sierra GameKing.

“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck