Inglis 20mm Cannon

[motto]

There seems to be vastly more information available in relation to small arms than larger weapons which can be difficult to get any information on at all.

As I understand it the allies used two quite different 20MM rounds. One was the Oerlikon which was a short cased low velocity round that allowed its use in simple 'blowback' weapons. These had their origins in the WW 1 Becker which evolved into the WW 2 Mauser FF. This type of cannon can be identified by the large recoil spring around the barrel just forward of the receiver.

The other 20MM round was the Hispano which was much longer in the case, obviously had a much higher velocity and required the use of a locked breech mechanism. The guns for the two rounds were totally different which was, I would think, the problem confronting Inglis.

To stretch the discussion a little more. I would like to know where the Polsten fits into the scheme of things. This seems to be another weapon that not much is known about. The people who were involved in developing these guns must have been aware of each other. More so if they were Australian and Canadian.

David