Possibly one of the first sub-machine guns, it fired 9mm Glisenti and had a combined rate of fire reaching 3,000 rpm.
Looks more like a AA gun (Anti-Aircraft) or A Mounted light duty MG? But I am not gonna say what it is cause I dont know nor have I even ever saw such a gun. So lets see what everyone else says.
By definition, it is a sub-machine gun. It was mounted on aircraft but to no effect.
I can see why it had no effect. Shooting 9mm at other planes is like shooting a BB gun at a tank. No effect. But nice pic anyways.
you can be damn sure its still a blast to let loose an few thousand rounds through!
This is just what one needs to remove unwanted squirrels from a bird feeder : )