The range to the target is measured or estimated as precisely as conditions permit and correct range estimation becomes absolutely critical at long ranges, because a bullet travels with a curved trajectory and the sniper must compensate for this by aiming higher at longer distances. If the exact distance is not known the sniper may compensate incorrectly and the bullet path may be too high or low. As an example, for a typical military sniping cartridge such as 7.62×51mm NATO (.308 Winchester) M118 Special Ball round this difference (or "drop") from is . This means that if the sniper incorrectly estimated the distance as 700 meters when the target was in fact 800 meters away, the bullet will be 200 millimeters lower than expected by the time it reaches the target.