off-map Aircraft Weapon --- Accuracy

[Mario_Fr]

I really don`t know.

30mm MK 108: barrel length 58cm; acc 6
20mm MG 151: barrel length 110cm; acc 21
20mm ShVak: barrel length 124,6; acc 16
7.92mm MG 17; barrel length 60cm (or 47,5cm); acc 25

Anyway, barrel length and muzzle velocity are not very important for accuray when ground strafing. In a plane you really don`t shoot at distances over 600m.
Of much more importance is the location of the gun. If it is in the wings, you have to regard convergence much more. If it is mounted in the fuselage, it`s much more precise.