The BS-1 RGA-86 "Tishina" / BS-1M 6S1 "Kanareyka" is a silenced Soviet 30mm grenade launcher. It was developed specifically for the Spetsnaz. It uses a bolt-action mechanism to load blanks into the chamber along with the 30mm grenade VOG-T. Pulling the trigger ignites the blank which in turn ignites the charge on the grenade causing the grenade to be expelled from the barrel. The BS-1 "Tishina" grenade launching system is one of the most interesting and impressive weapons that were developed for Soviet Spetsnaz. This system was adopted in the 1970s, to replace previously used stand-alone silenced / flash and noiseless 30mm grenade launchers known as "Device D" and "Device DM". The idea behind a "noiseless" grenade launcher was to hide the sound and flash of the grenade launch and thus give the shooter a greater chance to escape after a successful diversion behind enemy lines; the main targets for Spetsnaz during the Cold War were tactical nuclear missile launchers, C&C installations and equipment, fuel and ammunition storage facilities and parked tactical aircraft. The original BS-1 system included the 7.62×39mm Kalashnikov AKMSassault rifle with PBS-1 silencer, subsonic 7.62×39mm US ammunition, 30mm GSN-19 under barrel grenade launcher and grenade launching sight. When, during the late 1970s, the Soviet army switched over to 5.45×39mm ammunition, 7.62mm AKMS assault rifles with PBS-1 silencer were replaced with 5.45mm AKS-74UB compact assault rifles with PBS-4 silencers. The original GSN-19 grenade launcher was slightly reworked, mainly to use different launching ammunition. Other changes include different mounting brackets to better suit AKS-74UB compact assault rifles. These weapons are still in limited use with Spetsnaz elements of the Russian army and probably some other armies of ex-USSR countries. The GSN-19 silent grenade launcher is unusual in the fact that it is both muzzle- and breech-loaded. The standard projectile is a specially designed AP-I grenade with pre-engraved rifling. The warhead is designed to penetrate the hulls of tactical ballistic missile launchers, aircraft, C&C equipment, and then cause enough damage to render the target inoperative. The grenade has no propelling system in itself, as the launch is performed by special blank cartridges, which are loaded into a detachable box magazine. Cartridges are fed into the chamber by a manually operated rifle-type rotary bolt action mechanism. To achieve the noise- and flash-less launch, blank cartridges are discharged into the limited volume breech, which is fitted with a movable telescopic piston at the front. Upon discharge, this piston violently pushes the grenade out of the muzzle of the launcher, and then stops and seals the expanding powder gases inside the rear part of the launcher's barrel. After a short while the pressure inside drops to a safe level and the weapon can be reloaded by operating the bolt and then loading the new grenade from the muzzle which is then held in place by special springs. The muzzle velocity of the 30mm grenade for the 7.62mm version is quoted as "above 100 m/s", for the 5.45mm version it is listed as 175 m/s. The grenade launcher is attached to special brackets, welded to the host assault rifle. To fire the GSN-19 accurately and comfortably, the host rifle is equipped with a special folding grenade launching sight and with a removable, rubber, recoil-absorbing butt pad.
