Swulfe,
Try that same in the german side
I've got plenty kills in russian campaign but in german... you got that 15mm peashot for plenty of missions.
Doesn't work as well as 20mm
I just got 109G2 few missions ago, ahh.. how relaxing that MG151/20 is!
With 109F2, I got once 3 IL-2s in one flight, that was big deal.. but with G2 I could get many of those with its 20mm.
It also seems like german planes are made out of silk and russo planes of steel, that much easier it is to shoot down german planes.