Suppose you have a rifle scope that has 4 sets of crosshairs, for 100, 200, 300 and 400 yards. Now you use your top set of crosshairs and zero perfectly at 100 yards. Now suppose your bullet drop is appx. 20 inches at 400 yards, but you have no place to shoot 400 yards to check it. "IF" you held the bottom set of crosshairs on the bullseye, and shot at a target 100 yards away, would the bullet impact appx. 20" high?