It turned out pretty good!
It's an open bolt select-fire SMG. It uses 9mm Parabellum rounds, and it's weirdly unknown in the world
I like how it operates, although it's still slow for an SMG. It CAN chew through an entire mag at once, but sometimes it has trouble ejecting (the ejection is FULLY MECHANICAL unless it fails) and it can slow down for a couple secs until the spent shell is ejected properly. Also it has a weird mag holder that somewhat attracts it to the gun (like two conveyor belts on each side of the mag slot) so you just have to get it close and it will get inside itself! (Xray

)
To operate:
-Insert mag
-Select fire mode (S-safe, 1-semi, F-full)
-Press RETURN or pull trigger
PLEASE RATE AND COMMENT!
v1: Stolen heartlessly lololer's dummy (and the idea(hope you don't mind

)) but as the recoil is REAL then this has to run at 400 Hz and it may jam anyways
Doesn't it look AWESOME?
v1.2: Made everything 10 times more reliable than before, added weight to the rounds, and added a script that accelerates them at 200 m/s (sorry xD)
Now semi-auto will do bursts very rarely, not like before
Added a roller interruptor, like those on MP5s but quite different