AAF gunnery instructed that the average dispersion at any range to maximum effective was 4Mil in diameter. 666yds was considered maximum effective for air combat. The dot 6Mil, at ranges 200-600 was a good indicator of drop. This was substituted with a 1\2 degree cross or about 8Mil in the fixed reticle for the Mark 21(K14)\14A\14B as the standard.
If you keep your combat 200 and closer, most of your shooting will be the center of your glass reflector plate. But, then most of you don't know how to aim using the Mil ring and Mil dot as aiming aids. In many cases players have too much joystick induced bounce to aim with the historic gunsights I make, and their best kill range ends up being 200 and closer. Unless they have a just spawned pick on the runway, even if he's rolling. They watch the rounds against the ground and walk them on target.
Now if you are shooting from a P51D or P47 with all that ammo. You can shoot at 400 to 800 without a gunsight by hosing with the tracer stream like the way some players move their head position in the wirbel above the gunsight and watch the tracer stream to guide their shooting. It's just a computer program. In real life the german 20mm ack gunner used the gunsight to get close to the correct range while being taught to correct lead with the tracers.
My shooting instructor stressed knowing what your sight picture is at all ranges you know you will shoot at. For anything else, you know your dope. Something will always be used as your reference point to work from when you want to place rounds on a point in space you have chosen. The tracer stream, muscle memory, sound if you are blind, looking down the same barrel for a 1,000,000 rounds. Or just having been there so many times your memory is the gunsight.
I'm old enough that I lived life before there were computers and geeks who don't get out enough.