Flak vierling
 

Just out of casual observation here, seems the Germans went from 8mm mauser to 20mm and not much 13-15mm ground gun use at all except for late war flak drilling mounts. But why have a 4 gun mount that was fed by 20 round magazines instead of belt fed, or drum fed like oerlikon cannons were. Seems a bit over engineered then a slower rate of fire due to having to constantly change magazines, Overheating issues? Just the technology of the day?? Definitely a greatly respected weapons system that was effective.

It's all about getting the most ammo onto the target in the shortest time available.

If you think about it...at those times ...
How much time do you have to actually 'sight' an a/c so you can fire, a second or two ? - so you want to throw the max amount of lead at the a/c during this time !!
You reload during the gaps..

Germans are good at efficiency
:)