An old thread but a good question. Maybe if its stated better... What would be the optimum POA/POI difference at a 25 meter sight in target for the diopters to be correctly calibrated for range using NATO spec 55 gr. 5.56 using, the 1,2,3 or 4 setting? I.E. .5 inches high POI over POA using the 300 meter setting,, ect..