12.7×55mm STs-130

12.7×55mm
Type	Rifle
Place of origin	Russian Federation
Production history
Designed	2002
Specifications
Parent case	.338 Lapua Magnum
Bullet diameter	12.7 mm (0.50 in)
Case length	54 mm (2.1 in)
Overall length	94 mm (3.7 in)
Ballistic performance
Bullet mass/type Velocity Energy 7 g (108 gr) LP 845.154 m/s (2,772.81 ft/s) 2,500 J (1,800 ft⋅lbf)

The 12.7×55mm Subsonic cartridge is used in some Russian firearms such as VKS bullpup sniper rifle and ASh-12.7 bullpup battle rifle. The cartridge can carry a projectile weighing between from 59 grams (911 grains) and 76 g (1173 gr), yielding massive amounts of kinetic energy. The round can penetrate up to 16 mm (0.63 in) of steel at 200 meters or heavy body armor at 100 meters. The accuracy of this cartridge is claimed as to be 1 MOA at 100 meters range. Despite having the same designation, it appears that the ASh would not be able to feed or chamber rounds designed for the VKS due to significant length differences in the bullet component of the cartridge.

Cartridge variants for use in the VKS

• STs-130 (СЦ-130) - standard
• STs-130U (СЦ-130У) - for training
• STs-130PT (СЦ-130ПТ) - increased accuracy (59 gram bullet)
• STs-130PT2 (СЦ-130ПТ2) - increased accuracy (solid bronze bullet)
• STs-130VPS (СЦ-130ВПС) - increased penetration (76 gram bullet)

Cartridge variants for use in the ASh-12.7

• Legkoy Puley (LP) or "Light Bullet" - Light supersonic sabot-born lead bullet with an aluminum core weighing 7 grams (108 grains).
• Tyazheloy Puley (TP) or "Heavy Bullet" - Heavy subsonic lead bullet weighing 33 grams (509 grains).
• Dvukh Pul'niy (DP) or "Double-Bulleted" - Two bullets loaded inline weighing 17 grams (262 grains) each.
• Broneboyniy Puley (BP) or "Armor-Piercing Bullet" - Lead bullet with an armor-piercing weighing 18 grams (277 grains).