Out of curiosity I created a test terrain where I can spawn the majority of planes we shoot forward fixed guns with onto a bench stand leveled relative to the horizontal center line of the offline target. Then on zoom I can watch where my rounds hit at different ranges.
Here is the K4 with the MK108 30mm set at the game default convergence of 250 at 800, 600, 400, 200. Each ring of the target is 10ft wide. Screen capture is not that great for individual pixels so if you really want to see the dispersion just sit on a runway and pull up the target, go to full zoom and blast away. It's impressive to pull that target back to 25-50 yards to get the full impact of just how wide the dispersion area is.
The bench stand and you can see the plane center line for the blast tube lines up with the target.
800yds, the dark area just above the first tick mark is the impact area about 30ft low and wider than that to each side.
600yds, the dark area 10ft low is the impact and dispersion is about 20ft to each side. Screen capture does not get it all.
400yds, about 1ft low but the dispersion is about 10ft to a side.
200yds, dead on and the dispersion is about a 10ft diameter circle.
