9x39mm rounds are subsonic rounds modeled after the soviet 7.62x39mm cartridge but having a larger neck to accommodate the 9mm slug. These rounds were specifically made for special forces use as they were meant to be chambered in stealth weapons such as the AS VAL. Subsonic rounds do not create a sonic boom when fired from silenced weaponry due to their low velocity, making them even more noiseless when being fired, however to achieve this: less gunpowder is used in the shells and heavier slugs are used for better penetration to compensate for less combustion, thus subsonic rounds have a shorter range compared to regular cartridges. Despite this though, 9x39mm rounds have a lethal range of 300 to 400 meters.
- 9x39mm SP-5 Match-grade Full-Metal-Jacket (FMJ) Ball round
- 9x39mm SP-6 Match-grade Armor-Piercing Penetrator round
- 9x39mm PAB-9 Armor-Piercing Core round.