here is a chart with m193 out of a 16 inch barrel, it might not be 100% correct but it's close enough
0-200 yards you are worst case like 2.5 inches low. That means you if you have time to aim you aim at the top of the chevron and that's close enough to score a head shot, if you don't have time to aim you just put red on the dude and you should be close enough to score hits on a human size torso
at 250 yards you are either 5.5 inches low with the chevron or 5 inches high with the 300 m aim point, you can just use either if you have a torso, if you are trying to score headshots at 250 meters, idk good luck but it still increased hit probability over a red dot or irons. everything 400m out is a crosshair with no illumination. You basically have more or less the same holds as the old A1 style sights with the short range 0-250 yard battle sight and the 250-350 yard long sight between the top of the chevron and the tip of the 300 meter post