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 [1]
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 weight/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.)[2] 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.

Cartridge dimensions

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).

According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the 7.62×45mm can handle up to 430.00 MPa (62,366 psi) Pmax piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.[2] This means that 7.62×45mm chambered arms in C.I.P. regulated countries are currently (2014) proof tested at 537.50 MPa (77,958 psi) PE piezo pressure.

Non-official dimensions

There are definite differences in reported dimensions from non-official sources for this cartridge. Some of this may be accounted for by small errors in conversion from metric to inches, while others such as loaded length may additionally be attributed to different lengths of bullets being measured in loaded rounds. A sample list of various measurements is in the table below.

Various reported dimensions for the 7.62×45mm vz. 52
Source Case length Overall (loaded) length Bullet weight Loaded weight
Cartridges of the World [1] 44.958 mm (1.77 in) 59.94 mm (2.36 in) - -
Cartridge Corner [3] 44.958 mm (1.77 in) 57.40 mm (2.26 in) - -
Handloader's Manual of Cartridge Conversions [4] 44.80 mm (1.764 in) 62.23 mm (2.45 in) - -
40 let konstruktérem zbraní 1946–1986 [5] 45 mm (1.772 in) 60 mm (2.362 in) 8.5 g 18.9 g
Československé automatické zbraně a jejich tvůrci [6] 44.9 mm (1.768 in) 60 mm (2.362 in) 8.5 g 18.9 g

Wildcats

The 7.62×45mm case is also used as the parent case for a modified variant that is not officially registered with or sanctioned by the C.I.P. or its American equivalent, the SAAMI. Such cartridges which use commercial factory cases are generally known as wildcats. By changing the shape of standard factory cases (decreasing case taper and/or changing the shoulder geometry) the wildcatter generally increases the case capacity of the factory parent cartridge case, allowing more propellant to be used to generate higher velocities. Besides changing the shape and internal volume of the parent cartridge case, wildcatters also can change the original calibre. A reason to change the original calibre can be to comply with a minimal permitted calibre or bullet weight for the legal hunting of certain species of game or change external or terminal ballistic behavior. In his spare time Chis E. Murray has been developing the ultimate military cartridge which he calls the 7×46mm Universal Intermediate Assault Cartridge.[7] The 7×46mm is designed to replace both the 5.56mm and 7.62mm NATO cartridges. It is low recoil and so can be used from carbines, but has long enough range to be used in machine guns and designated marksmen rifles. Its overall length has been optimized so that guns chambering it would be bigger than an AR-15 but smaller than an AR-10.[8]

Gallery

See also

References

  1. 1 2 Barnes, Frank C. (2006). McPherson, M.L., ed. Cartridges of the World (11th ed.). Gun Digest Books. pp. 354, 375. ISBN 0-89689-297-2.
  2. 1 2 C.I.P. TDCC datasheet 7,62 x 45
  3. ↑ CartridgeCorner.com
  4. ↑ Donnelly, John J. (1987). The Handloader's Manual of Cartridge Conversions. Stoeger Publishing. p. 846. ISBN 978-0-88317-269-8.
  5. ↑ Čermák, Jiří (1999). 40 let konstruktérem zbraní 1946–1986 (Od samopalu ČZ 247 ke zbraňovému kompletu LADA). Brno: Ardent. ISBN 80-238-3397-9.
  6. ↑ Popelínský, Lubomír (1999). Československé automatické zbraně a jejich tvůrci. Praha: Naše vojsko. ISBN 80-206-0567-3.
  7. ↑ 7x46mm UIAC (Universal Intermediate Assault Cartridge)
  8. ↑ Major Thomas P. Ehrhart Increasing Small Arms Lethality in Afghanistan: Taking Back the Infantry Half-Kilometer. US Army. 2009
This article is issued from Wikipedia - version of the Sunday, December 27, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.