Got no dogs in the fight, 50 cal or otherwise but if you just do the math---

If you have a one MOA rifle(very accurate indeed) you could expect a 5 inch group at 500 yds with PERFECT conditions and great shooting.Add it human frailty and weather conditions and you can balloon that 40% to 7 inches in diameter easy.

Past 500 yards the math goes against you-- AT 1000 yds you have only a 10 inch circle of accuracy with maybe a 30-40% balloon due to other variables.Thats a "vital zone" of 13-14 inches which is ridiculous for a deer or an antelope.An elk with a 24" chest would have a vital zone of 1/3 of that depth or 8 inches. And your gonna shoot at that animal from 700-800 yd?? Crappy choice by my estimation and very possibly injuring the animal irresponsibly.The animal deserves better than that.

Warfare is different with different objectives. Wounding one individual can require 2 other to deal with him and decrease the force of your opposition(or so the song goes)
The human toso is upright and this gives a larger surface to strike vertically.Yada, Yada, Yada--

50's are great fun but not for hunting long range game in my book--just my personal opinion--