I think it was used as a reserve weapon for Volksturms at the end of the war. It might be similar to soviet maxim-tokarev ingame (not sure about the rof though)
USSR should get a bomber like Tu-2S
and something like La-9 or late version of Yak-3/9 as fighters
The number of ground vehicles including the upcoming additions total at 132.
Of those 132 four are SPAAG representing 3% of all ground vehicles. Of those 4 two are earned in a limited time event, so a lot of players can only unlock 2 SPAAG from the tech tree, representing a mere 1.5% of all ground vehicles that’s only available to 2 out of 4 factions.