.303 / 7.62×39

.311 / .303 British & 7.62×39mm

History & Design Intent

The .311-.312-inch bore covers the older .303 British (adopted 1888 for the Lee–Enfield) and the Soviet 7.62×39mm (1943, the cartridge of the SKS and AK-47). Both reflect early-to-mid 20th-century military doctrine — the .303 a full-power rimmed round, the 7.62×39 an intermediate cartridge built for controllable automatic fire.

Operational Profile

The 7.62×39mm pushes a 122–124 grain bullet around 2,350 fps, offering reliable, low-cost performance to ~300 yards and defining the AK pattern. The rimmed .303 British remains a capable medium-game and surplus-rifle cartridge. Both are valued today for affordability and historical platforms.