Gw Pat 90

The Gewehr Patrone 90, or "Rifle Cartridge 90", is the standard round used by the Swiss military in its assault rifle, the SIG SG 550.

History

The GP 90 5.6 mm was designed for the SIG SG 550 when it came into production in 1987, replacing the SIG SG 510. Previous experience of a change in standard rifle had proved that changing the distance of fire for the training ranges was more expensive than the design of a new ammunition; this prompted the design of a cartridge nominally capable at 300 meters. The Swiss refer to the round as the 5.6 mm, although it is interchangeable with the 5.56x45mm NATO round.

Characteristics

Cartridge Data

* weight: 12.2 g
* case material: CuZn - alloy
* primer: SINTOX - non toxic
* propellant: double base
* projectile: FMJ
* ballistic coefficient C 1: 0.331 (ICAO) / 0.337 (Army Metro)
* projectile weight: 4.1 g / 63 grain
* jacket material: tombac
* core material: PbSb - alloy
* dimensions: in accordance with C.I.P.

Technical Data

* temperature range: between -30°C and +60°C
* muzzle velocity: min. 905 m/s (test barrel 500 mm)
* mean chamber pressure: max. 4300 bar (PT)
* accuracy 100 m: 100% radius 21 mm (0.72 MOA), 10 rounds
* accuracy 300 m: 100% radius 63 mm (0.72 MOA), 10 rounds

Production and usage

The cartridge was also designed to reduce pollution by controlling lead emissions. The ammunition is produced by RUAG Munition, a company of the RUAG technology group [http://www.swissmun.com/] . It is a steel jacketed projectile containing approximately 95% Pb, 2% Sb, 3% Cu, and designed for terminal ballistic instability. [http://www.swissmun.ch/d/press/press050701_e.htm] .

The Gw Pat.90 is used both in the Swiss military and in sport shooting. The very high level of individual training in the Swiss militia (every single soldier bearing a weapon has to shoot for qualification once a year; see Gun politics in Switzerland) and the overall use of the Gw Pat.90 by the many Swiss citizens who shoot in competitions and for amusement has resulted in significant input on its usage. Over 1 billion cartridges have been produced as of 2005.

External links

* [http://www.swissmun.ch/e/defence/small-arm_text.htm Small Arms]
* [http://www.swissmun.ch/d/press/press050701_e.htm www.swissmun.ch]
* [http://www.swissrifles.com/ammo/ www.swissrifles.com]
* [http://www.ruag.com/ruag/juice?pageID=91585 RUAG Ammotec page]
* [http://www.ruag.com/ruag/binary?media=152017&open=true RUAG Ammotec Sintox SWISS ORDNANCE cartridge fact sheet]
* [http://www.cybershooters.org/swiss_ammunition_enterprise.htm Swiss Ammunition Enterprise]