VSS "Vintorez" had been designed around a proprietary cartridge, designed solely for stealthy shots in the presence of enemy forces, the SP-5/SP-6. Measuring 9x39 mm, it is loaded with a heavy bullet, which travels with subsonic speeds thus carrying considerable more energy that smaller and faster rounds. The SP-5 is standard ammo, while the SP-6 is a special armor-piercing round.
Technically, VSS "Vintorez" is a gas-operated silenced rifle. It, just like AS "Val", has separate safety lever and fire mode button. However, automatic fire is intended only for emergency situations, and puts inordinate strain on the gun.
VSS "Vintorez" is intended for the sniper duty.