OK, here's 2 options. #1, figure out where to aim on a deer at 800 yards by calculating all the variables like wind speed, humidity, etc. etc...then take a shot. Or #2, hop on your 4 wheeler and drive (or just walk) 400-500 yards closer to the deer, park the 4 wheeler (or stop walking), find a good rest and take a shot at less than 400 yards. I dont understand why anyone would want or need to take a shot at a deer at 800 yards, much less 500 or 600yards.

Ridge, sounds like you could quit your day job and become a sharpshooter, unless you already are.