looking for a WW2 aircraft cannon.

It is a unique aircraft cannon. If I could remember, it is a multi barrel weapon, all the barrels are preloaded with ammunition and they do not rotate. I think all the barrels fire in a single blast. I believe there is more than 5 barrels, do not know exactly how much, but that’s its function. Does someone know what it’s called? any images?

This any help to get you started

http://www.warbirdsresourcegroup.org/LRG/Secweap.htm#GUNS