How a PSS silent pistol works

The PSS silent pistol or MSS "VUL" (or "Wool" in English)[1] is the last completed weapon system resulting from the Soviet development of silent pistols operating on a sealed cartridge system. Two previous designs were considered unacceptable for use due to their limitation to two shots. Earlier systems included the MSP and SP-4M double barreled pistols. Developed around 1980, the PSS was first issued to KGB Spetsnaz in 1983. Intended for assassinations and reconnaissance, it is under production in the special weapons foundry at TsNIITochMash. PSS pistols are still in use by elite special forces units of many nations, as well as by some FSB, MVD.