Nothing. A zero at 25 yards will hit just about right at 25, 50, 100, 150, and 200 yards. Hell, if he knew the spot, a zero at 200 would need no adjustments. The bullet drop on a 223, 270, 6.5 creed or anything else is nothing.
An acss red dot makes 200 a drop shot a 2.5 or 3x acss or bdc reticle an instant hit.