No wind zero.
when I shot with the rifle teams we always got to the range early AM. The wind was normally nil early and either we practiced offhand (standing) or we did long range shooting. With no wind you would get a better zero in no wind conditions so you could
get a better idea of how the wind affected your shots as the wind increased as it started coming up. But we shot with the same weapons, same ammo and other than differences of ammo lots and different range effects your zero would hold pretty consistently. For instance, my prone zero might be at zero on the windage drum, my prone rapid fire 1 left of zero and sitting rapid fire l left of zero for my no wind zero.
With the same rifle, barrel length, usually rate of twist, and ammo the military had developed wind charts we all took to the firing line or memorized. All we had to do was accurately call the wind speed and direction and refer to the chart. If I can remember it, I will bring one of my old scorebooks and charts next time.