[RAF_Magpie]

:?:

The Mauser MG 213 was a 20 mm aircraft-mounted revolver cannon developed for the Luftwaffe during World War II. It was never put into service, but the principles formed the basis for several post-war developments by the Allies. A 30 mm version was developed as the MG 213C or MK 213 and it was this that led to the British ADEN and French DEFA cannons. [1]

http://en.wikipedia.org/wiki/Mauser_MG_213

It was available in 2 calibers one was the 20x135mm derived from 20mm flak, and 30x85B

The rate of fire was 1100-1300, the modern series of Aden, Defa, and Mauser BK-27 was derivated from it