The StA-11 Submachine Gun unlocks at level 42 and appears as the PP-19 Bizon (Tatonka Submachine Gun).
Acts as a somewhat of a combination of the Micro Uzi and Tatonka, boasting a high rate of fire, a helical 48-round magazine, and decent stability and accuracy. And like any other Helldivers 2 weapon, doing a partial reload will discard any current ammo in the magazine.
Purely used with iron sights, as it does not support vanilla optics, nor any of the Helldivers 2 ones.
Currently re-uses the Tatonka's non-empty reload animation for both reloads.