I agree, up to 50 yards or so the 10mm should work well on small to medium game. For deer I would use the hotest 180gr jackedted hollowpoints you can find. I carry my glock 20 loaded with buffalo bore's 180gr Speer Gold Dots loaded to 1350 fps, and they seam to bring out this calibers full potential. The only big game I have taken with it so far was a 175lb hog at about 25 yards. I hit him right behind the shoulder and I found the slug under his hide on the off side after going thrugh a rib.
As far as what the other guys are saying about a 10mm auto not being the best deer killer, I must agree, the best and easyist thing to use would be a rifle!
But thats not why we hunt with handguns, now is it!