In one of his final columns, Jeff Cooper presented what he felt would be the next great marksmanship challenge which was 20 rounds in a 20" circle at 1000 yards in 60 seconds or less. I've always felt that would be the weapon in the hands of the person who did it.
What kind of rifle can do that?
These are ten shot groups. The time is what will get you. You'd have to fire and recover in three seconds for each shot. It's not that a human being can't do it, but the 1,000 yard target is tiny, even in a 30 power scope. You have to find it after each shot. That's what makes it pretty much impossible.