REDMISTMD: I'm a bit dubious about snipers shooting 1,000 yards, OFFHAND. Sure, if you do everything reasonable to make a rifle a 1000-yard critter, it's quite possible from a rest. Plenty of books on the subject. But you're not going to stand erect, take your sight, and touch it off at that distance and expect a one-shot kill.
Harry Pope was known as "The Human Bench Rest", and shot incredible groups at 200 yards. He used a Ballard single-shot. He'd reprime the case, and then load powder and bullet from the muzzle.
I've watched my father "call the white spot" on a deer's neck, offhand, at 250 yards; there are witnesses to the same call at 450.
People like these are the exception, not the rule, in my experience.
I used to hunt one 2,000-acre gently-rolling pasture which was mostly 4' to 8' mesquite brush. You walked and walked, trying to get somewhere; when you got there, you weren't anywhere! If you saw a deer, the only shot you had was offhand. Period, end of story.
Out in my home country, typically you walk and hope to jump Ol' Biggie out of bed and hit him on the run. He'll be somewhere between 50 feet and 500 yards, full throttle in overdrive. Ya gotta figure distance, angle, lead and holdover and do it all in about one second--or go hungry.
Later, Art