There's no tags for this but that gun is the SMG prototype that Mikhail Kalashnikov tried to submit for the 1942-1943 Soviet SMG trials. The closest to a name you can give it would be PPK-42 (PP being "Submachine gun" in Russian and K being the initial for the designer's surname).

https://en.m.wikipedia.org/wiki/File:AK-SMG-1942.jpg

Edit: For those who don't know, Mikhail T. Kalashnikov is the designer of the AK series of rifles.

rookie52 said:

There's no tags for this but that gun is the SMG prototype that Mikhail Kalashnikov tried to submit for the 1942-1943 Soviet SMG trials.

https://en.m.wikipedia.org/wiki/File:AK-SMG-1942.jpg

Edit: For those who don't know, Mikhail T. Kalashnikov is the designer of the AK series of rifles.

Damn! You must know your guns really well