It goes without saying that silent weapons are required in `delicate` situations. Usually for these situations silencers are used. But Soviet designers designed another way. They invented special silent bullets. Adopted circa 1983, the “Special self-loading pistol” (“PSS”) is a semi-automatic pistol with unique ammunition, which is silent – not suppressed.
It has a 6 rounds single-stack column detacheable magazine, and fires the proprietary 7`62x41mm "SP4" silenced and smokeless ammunition, which is much more compact and much more silent in action, than `conventional` silenced pistols. The cartridge contains an internal piston and a propelling charge, with the stem of the piston against the base of the bullet. On firing, the piston delivers enough impulse to project the bullet from the barrel to an effective range of 50 or more meters. The piston then seals the cartridge neck, preventing noise, smoke, or blast from escaping the barrel.
To be silent the bullets also have to travel slower than the speed of sound. The loudest noise is that of the weapon cycling. The subsonic SP-4 cartridge can also penetrate a 2mm steel plate or standard steel army helmet at 25 meters, retaining its lethal effect.
The pistol was developed for the special forces and the KGB, in need of compact, silent weapons for covert operations such as reconnaissance and assassinations. At the present time the PSS is used by elite Russian special forces units.
