Specifications Vykhiop Caliber........................................................................12.7 mm Cartridge...............................................................12,7×54 mm Pistol weight w/o optical sight and cartridges................6.3 kg Complex length.............................................................795 mm Barrel length.................................................................200 mm Muzzle bullet velocity.................................................290 m/sec Effective rate of fire..............................................30/60 rds/min Sighting range..................................................................5 rds

    In 2002 the TSKSB SCO design bureau (subsidiary of the KBP design bureau, Tula) presented a new 12.7 mm sniper system under the codename "Vykhlop" (Exhaust). The dedicated research and development project was started in 1999 on the request of the Federal Security Service of the Russian Federation. The upgraded system was adopted for service in 2004. For the first time the system was presented to public in 2005. The system passed operational testing in combat situations by special-purpose units of the Federal Securely Service.
     The system is an exotic crossbreeding of noiseless and large-calibre rifles, it allowed combining low firing signature with the unique capability of defeating enemy manpower protected by body armour or hidden behind obstacles (doors, glasses, thin wails, car skins, and so on) as well as hardware and transportation means It should be noted that the weapon weight and size are close to those of a conventional sniper rifle of common calibre.
     The system includes a magazine-fed special large-calibre sniper rifle (abbreviation VKS comes from Russian "vintovka krupnokalibernaya snaiperskaya" — large-calibre sniper rifle) and special 12 7 mm rounds with subsonic bullet. Several 12.7 mm cartridge variants are offered:
— enhanced accuracy STs - 130 PT sniper cartridge with full-jacketed bullet weighing 59 g similar to that of the 12.7 SN round. Muzzle energy of the bullet is about 2,500 Joules. Accuracy of fire declared by the manufacturer for such round is characterized by dispersion of 2.5 cm in diameter at a range of 100 m, which falls within one minute of angle;
— enhanced accuracy STs-130 PT2 sniper cartridge with whole (monocomponent) bronze bullet;
— enhanced penetration STs-130 VPS sniper cartridge with armour-piercing bullied weighing 76 g with heat-strengthened core protruding from jacket, this round is designed to engage manpower wearing body armour protective means of the 5th/6th protection class, or light armoured hardware at a range of up to 200 m;
— STs-130PU practice cartridge designed for mastering weapon loading procedures and checking operation of its mechanisms.
As was earlier stated, the bullet of the STs-130 VPS round can penetrate an armoured vest of the 5th protection class at a range of 100 m, and a steel plate 16 mm thick at a range of 200 m. The rounds are specially made, housed in a special case, their full length is 97 mm. The heavy bullet extends effective aimed range to 600 m, which exceeds by 1.5 times that of the 9 mm VSS and VSK-94 sniper systems.
     The VKS rifle born in the TSKIB design bureau has adopted the bullpup layout with a 5-round detachable box-type magazine positioned behind the pistol grip. The rifle features a reloading handle with direct travel (without turning).
     Optical or night sight is mounted on top the receiver, mechanical sights are also available The rifle is provided with a folding bipod fitted in the middle part of it.
     It is worth recalling that the very idea of subsonic 12.7 mm calibre round with heavy bullet is not new. As far back as the 1950s the famous designer M.M. Blum proposed to increase effective range of subsonic ammunition fired from a silenced firearm by changing over to 12.7 mm calibre, but at that period it remained at experimental level. Nowadays the very idea has been implemented by other designers in other conditions.