7.62×45mm

7.62×45mm vz. 52
Type	Rifle
Place of origin	Czechoslovakia
Service history
In service	1952–1957
Used by	Czechoslovakia
Production history
Designer	Alois Farlík
Designed	1940s
Produced	1952
Specifications
Case type	Rimless, bottleneck
Bullet diameter	7.83 mm (0.308 in)
Neck diameter	8.66 mm (0.341 in)
Shoulder diameter	10.56 mm (0.416 in)
Base diameter	11.30 mm (0.445 in)
Rim diameter	11.30 mm (0.445 in)
Rim thickness	1.50 mm (0.059 in)
Case length	45.00 mm (1.772 in)
Overall length	60.00 mm (2.362 in)
Case capacity	2.79 cm3 (43.1 gr H2O)
Rifling twist	280 mm (1 in 11.03 in)
Primer type	Berdan rifle
Maximum pressure (C.I.P.)	430.00 MPa (62,366 psi)
Ballistic performance
Bullet mass/type Velocity Energy 130 gr (8 g) 760 m/s (2,500 ft/s) 2,455 J (1,811 ft·lbf)
Test barrel length: 520 mm (20.472 in)

The 7.62×45mm (designated as the 7,62 × 45 by the C.I.P.) is a rimless bottlenecked intermediate rifle cartridge developed in Czechoslovakia. It is fired by the Czech vz. 52 rifle, Vz. 52 machine gun and ZB-530 light machine gun. The round was later dropped from use when the Czech converted to the standard Warsaw Pact round, the 7.62×39mm (fired by vz. 52/57 rifle and vz. 52/57 light machine gun). Its muzzle velocity and muzzle energy are slightly higher than that of the 7.62×39mm cartridge.

The 7.62×45mm has 2.79 ml (43.1 grains H₂O) cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action and semi-automatic rifles and machine guns alike, under extreme conditions.

7.62×45mm maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

Americans would define the shoulder angle at alpha/2 ≈ 24.9 degrees. The common rifling twist rate for this cartridge is 280 mm (1 in 11.03 in), 4 grooves, Ø lands = 7.62 millimetres (0.300 in), Ø grooves = 7.88 millimetres (0.310 in), land width = 3.50 millimetres (0.138 in) and the primer type is Berdan or Boxer (in large rifle size).

...
Wikipedia