Most ballistic calculators seem to default to a 1.5" scope heoght which does take in most conventional rifles. If not exactly correct, it's close eonough. OTOH, some of the guys shooting ar types probably have much higher scope heights. Ditto some of the fal guns and certainly an SKS. The higher scope heights will make a dramatic change in the PBR arc.
Coloradoete has it right on, IMO. Calculators are fun but actual testing at range will often illustrate that the ballistic calculators are not a reliable estimator of trajectory.
