I watched a Youtube video of IL-2 about weapon calibration and using sights to check the target range. Unfortunately, his examples had just FW-190 and Hurricane, and he noted that FW-190 fills the hurricanes sights (wingtips touching the circle) at 100 meters. He then noted that in USAAF sights, the 190 fills the sights at 150 meters. I took out a pen and pencil, and started calculating distance where I-16, LaGGs, MiGs and IL-2 s fill the sights. Why? Because Brewster B-239s have USAAF sights. I decided that a good compromise is 140 meters calibration. Then I decided to put it in practice. So i went to quick mission builder, took a Brewster for myself, I-16, MiG and IL-2 as friendly aircraft so that they don't shoot back and don't try to dodge.
Guess what? IT WORKS!
Wen't to campaign mode to test it out: shot down three I-16s. Another mission: three IL-4s. Another mission: two TB-3s.
I love these things!