fastmongrel
1st Sergeant
The German 20mm guns were the FF and the 151 and they were very different animals.
ROF FF 8 rds/sec, 151 12 rds/sec
MV FF 585 m/sec, 151 720 m/sec
The 109E as we know had the FF and the F4 the 151, what the 109F2 had when it was upgunned I do not know.
Also the ballistics of the FF round were pretty appalling at anything much more than point blank it had a trajectory like a rainbow. Fine for its intended use against bombers but less good for hitting a manouvering fighter.