ASh-12.7

The ASh-12.7 (АШ-12.7, which stands for "Автомат штурмовой 12.7мм" or "Assault automatic rifle, 12.7mm") battle rifle is a dedicated CQB/Urban Operations weapon, developed by TsKIB SOO ("Central Design and Research Bureau of Sporting and Hunting Arms"), a subsidiary of the KBP Instrument Design Bureau of Tula, Russia, by request from the Russian FSB (Federal Security Service).  The weapon was designed with extreme short-range stopping power in mind for FSB urban combat units.  According to the Russian press, the first batch of ASh-12.7 assault rifles was delivered to the FSB in late 2011. 

Overview
The ASh-12.7 is a dedicated "Close/Urban combat" weapon for high-risk law enforcement operations, which must combine high stopping power with limited penetration and a short 'dangerous range', to avoid collateral damage to innocent bystanders or hostages.  To achieve these goals, the designers of the ASh-12.7 assault rifle developed special large-caliber ammunition, loaded with a variety of bullets.  Ammunition for the ASh-12.7 is the 12.7×55mm straight-walled, rimless brass case based on .338 Lapua Magnum, originally developed by the same organization that developed the silenced VKS sniper rifle.  Standard loading for the ASh-12.7 is a lightweight, subsonic bullet with an aluminum core, exposed at the front and hollowed at the rear and partially enclosed into a bi-metal jacket.  The cartridge has a bullet weight of 48.14-76.08 grams and a muzzle velocity of 290–315 metres per second.  It has several loadings; light, heavy and a duplex load with two light bullets. 

This new Russian ".50-caliber" cartridge bears certain conceptual similarities to a family of big-bore cartridges developed in the US for the AR-15 platform, such as .458 socom, .499 LWR or .50 Beowulf, although the Russian cartridge uses a longer case and generally a heavier bullet load - its US counterparts are usually loaded with bullets weighing 19 grams/300 grs and up. 

The ASh-12.7 assault rifle has a bullpup layout, with a stamped steel receiver and a polymer housing/stock.  It is believed to use a gas operated, rotary bolt action.  Firing controls include two separate levers; a fire mode selector (Semi/Auto) at the rear and an ambidextrous safety (Safe/Fire) above the pistol grip.  There are several configurations of the basic rifle.  The first one features an integral carrying handle with a built-in rear diopter sight and a folding front sight.  A length of Picatinny rail is installed on the carrying handle to accept various optical sights.  Another version that was observed on some photos features a "flat top" configuration with a Picatinny rail running on top of the receiver, as well as front and rear sights installed on folding bases.  Other variations have a Picatinny rail below the fore end or a 40mm underbarrel grenade launcher.  Muzzle devices include a muzzle brake or a quickly-detachable suppressor.  The equipment of the Russian law enforcement with the advanced ShAK-12 assault rifles is underway. 

Ammunition
12,7x55mm Легкая Пуля (Legkaya Puleya (LP) > "Light Bullet") [Bullet Weight: 7 grams (108 grains)] Light supersonic saboted lead bullet with an aluminum core. 
12,7x55mm Тяжелая Пуля (Tyazhelaya Pulya (TP) > "Heavy Bullet") [Bullet Weight: 33 gram (509 grains)] Heavy subsonic lead bullet. 
12,7x55mm Двухпульный (Dvukhpul'niy (DP) > "Double-Bulleted", "Duplex Bullet") [Bullet Weight: 17 grams (262 grains) each] Two bullets loaded inline.   
12,7x55mm Бронебойная Пуля (Broneboynaya Pulya (BP) > "Armor-Piercing Bullet") [Bullet Weight: 18 grams (277 grains)] Lead bullet with an armor-piercing core. 

Users

See also
RSh-12
List of Russian weaponry
List of bullpup firearms
List of assault rifles

References

Category:12.7 mm firearms
Category:Bullpup rifles
Category:Assault rifles of Russia
Category:Izhevsk machine-building plant products
Category:TsKIB SOO products