Feel the Power, young jedi.Thats the way to get a firing solution in an ack.
In WWII the germans estimated, that they need around 3000 shots for one destroyed plane.
They used Kommandogeräte (a combination of measuring system and analog computer) to estimate the approximate position of the target, if it is flying straight and level at the same speed. We do not have such assistance.
When you are sitting on the ground and want to hit a plane flying by, the only constant you have, is the flying path and speed of your shell and even that have a dispersion.
The distance on your targets icons might be porked by lag, even so its flying path.
The speed of your target you can judge into very slow, slow, medium, fast, 262.
Don't compare yourself to the miracle AI ack on the fields, that kills you, when you are jinking at top speed, but miss you, if you fly straight and level at stall speed

In an ack the closure rate between you and your target is much higher compared to airborne gunning. So start early shooting about 2k for planes going straight into you.
On planes flying by don't shoot over 1k. Would be pure luck if you hit anything above it.
Do not use gun zoom. You loose to much of your sight field that you need for aiming.
Take a big lot of lead on targets flying by.
Dont trust the tracers.
Learn by the results.
Tofri