I agree with Quilly. You know what I'd like to see is the makers of every .50BMG rifle or other long range type rifles to include a paper on the ethics of long range hunting. A basic do and don't list. Besides shooting skill from what I call a field firing position you also have to factor in "BUCK FEVER" and I always subtract 100yds for that. Which puts me at 500yds. Once as a experiment I stood up in full view of some deer at about 400yds and took a few steps parallel to them so they could surly see me move and they bolted back into the woods. Of course that was one instance. But they do recognize the human shape as a danger from greater distances than we may think.