Vyacheslav Shpakovsky special purpose SMG.
Fires an H-shaped projectile.

>What if we make an H-shaped multi-caliber bullet and equip it with a poly-wedge tip made of tungsten-molybdenum alloy?

https://archive.is/PuZbT
https://topwar.ru/158664-mnogokalibernaja-pulja-i-pistolet-pulemet-specialnogo-naznachenija.html