quite interesting thread here, It was common (still is) to "battlesight" the main gun at some preset range. There fore it was quite easy to make adjustments with the stadia and your reticle in the gunsight according to the distance to the target. The long range shots also must take into account weather, ammo temp, and the heating up of the gun commonly referd to as gun tube droop in the larger calibers... just my 2 cents in euro.