What about a Ultramachine gun i.e Ultralightmachinegun? In that case you are looking for the LAD.

>>63965279
>>63965603
Here he is, the mad LAD himself:

https://en.wikipedia.org/wiki/Nikolai_Afanasyev

Of course, it's the guy who designed all the weird fish shaped guns.

https://en.wikipedia.org/wiki/TKB-011