First, you better check with the state your hunting in! Some states limit the caliber, and or the weight/grain of the bullet to a degree.
If range and hunting are in the same paragraph, check out that new 7mm win short mag! It has pretty good ratings and range to boot! 800 yards is a hell of a shot, better take in account the cuvrature of the earth! hee hee!
I use a .300 win mag in a Savage rifle, and it's one of the best I've shot. I do like my Browning Stainless Stalker .338, though!!

GOOD LUCK!!---Remember, opinions are like..........everyone has one!!!

IN THE KILLZONE!