Originally Posted by Strider
I voted 800 yards. I have several deer kills in the 500 and 600 yard range, and one antelope at 780 and that one was in a 20 mph wind. My STW can do better than I can. I started shooting a 1000 yard prone course monthly several years ago and that has helped my confidence and performance tremendously. I am not sure I will get the chance to practice enough to feel confident beyond the 800 yard-mark.
You hit on a very key point here.
When you practice at long range, it builds confidence that you can indeed "pull off the shot" when the time comes.
I've seen time after time that if the shooter lacks confidence in their weapon and/or their own ability the results will usually not be favorable.
Conversely, when you are well practiced and well equipped, you have the confidence to get behind the gun and deliver.