what round are you shooting? I used to sight in 30-06 1" high at 100 yards to make it more or less zero'd at 200. You'll have to check the ballistics chart for the round you are shooting, and figure where you want it zero'd in at. Sighting in at 100 for a 200 yard zero is done because you are too lazy to walk the extra 200 yards each time to check target, or you don't have the range needed to shoot an actual 200 yard target.