SKS, Chinese Type 56 Rifle

Specifications:
Weapon nomenclature - Samozariadnyia Karabina Simonova (SKS)
System of operation - Gas, Semi-automatic fire only
Bolt type - one-piece, tipping, rear-cocking
Weight (loaded) - 8.8 lbs.
Length, barrel - 20.34 inches
Length, overall - 40.16 inches
Feed device - 10-round, fixed, staggered double-row box magazine
Sights, front - Hooded post
Sights, rear - Tangent leaf, graduated from 100 to 1000 meters
Cartridge - 7.62 x 39 Soviet M43 (Type PS ball)
Muzzle velocity - 2411 fps
Bullet weight - 122 gr.
Working pressure - 45,000 psi
Bore diameter - .301 inches
Groove diameter - .311 inches
Direction & rate of rifling twist - Right, 1 turn in 9.45 inches.

Operation:
When the rifle is fired, gas enters the gas port housing under pressure to thrust the piston rod back against the short tappet rod. In moving back, the tappet rod slides through a hole in the rear sight base and a corresponding one in the top of the receiver to strike the bolt carrier.

The claw-like arrangement of the bolt carrier cams the rear end of the bolt upward, unlocking it completely after 7/16" of rearward travel. The kinetic energy imparted to the bolt carrier upon being struck by the tappet rod is sufficient to cause the bolt and bolt carrier to travel together 3 7/8" rearward to extract and eject the fired case and to compress the recoil spring.

The compressed recoil spring forces the bolt and carrier forward to strip a cartridge from the magazine and chamber it. The camming surfaces within the bolt carrier force the rear end of the bolt down into the locked position. When locked, the lower rear end of the bolt butts against a hardened steel crosspiece set within the receiver.

Ammunition:
Surplus military ammunition from Com Bloc nations is currently banned from importation. Some ammunition imported before this ban is still available. Winchester (USA) and Remington (UMC) supply military ball type ammo in 7.62x39 which is superior to Com Bloc ball. Trajectory data supplied here is generic and presumes a maximum point blank range (bullet remains within 6 inches of line of sight) of 300 yards.