Think we are just calling horses well horses here the only thing that does not suffer drop is a laser and they do have lasers that can knock things off however your both right A) The projectile does cross the line of sight twice as per illus and bullets do not rise of their own accord they are aimed up to compensate for trajectory.

But the original OP and a few posts that have been proffered it is feasible to sight in at 25 yards to see where its printing then step it out once you have L-R sorted the elevation can come at greater distances I use 25 for L-R getting it plum dead on as no variables that close besides if you say that at 25 yards you're within 1/4" is ok then at 1000yds then you'll be hitting 2 targets over from your assumed correct 25Yd zero, if not hitting in the next paddock.