Name: SKS (Samozaryadny Karabin sistemy Simonova > "Self-Loading Carbine, Simonov-designed system")
Type: semi-automatic carbine
Country of origin: USSR/Russia
Variants: SKS, ОП СКС, МР-163 (ОП – СКС), another variants with external magazines.
Caliber: 7.62x39 M43 Soviet
Action: short gas piston
Feed system: internal 10rds magazine (clip or manual loading), external box magazines in some variants
Customization: Muzzle devices, gas block, rear sight, magazine, mounts and rails for attachments. Another modules in some variants.
The SKS was meant to be a replacement for the M1891 Mosin-Nagant rifle in Soviet service. It was originally supposed to be supplemented by the AK-47. Field exercises proved that the AK-47 was more effective and versatile than the SKS. Teething problems with mass-production of the AK-47 delayed its complete replacement of the SKS.
Production of the SKS was slowed beginning in 1954 and was completely stopped by 1958. The SKS was relegated to use by second-line formations. Other Communist Bloc nations either received the SKS as military aid or made copies of their own.