Malorian Arms Sub-Flechette Gun (2020)

Malorian Arms Sub-Flechette Gun is flechette submachine gun, a semi-bullpup configured weapon using a rotary bolt system similar to the proven M-95/G-11 operating system. This weapon uses the new 10mm caseless flechette round containing six steel penetrators capable of defeating any ballistic cloth body armor in present use. (Roll 106 to determine number of penetrators that hit per round. Each penetrator does 106 damage; armor x1/4. All penetrators from a single round hit in the same Body Area.) Equipped from the factory with three-round burst/full-auto capability, and an integral compensator. Ammunition magazines come in ten- and thirty-round capacities.

Cyberpunk RED
The Malorian Arms Sub-Flechette is still very exotic and better than most of its competitors still but, it can't use modern armor piercing rounds because its limited to its own custom range.