When you jump out of plane, there’s “forward throw”. In layman’s terms, this means that the jumper moves forward at the same speed as the aircraft until their speed is bled off due to drag. Which is important when you’re trying to hit an LZ be it personnel or cargo.
So instead of training via trial and error we used some smart people to help us determine “lead in meters” based off the ballistic coefficient and drag models of the aforementioned rounds.
It was actually pretty spot on.
My spotter kept a knee board on with all the leads.
And because it was in meters you can apply it to any reticle.
I’ll look for it.