P90

The FN P90 is a selective fire personal defense weapon (PDW) designed and manufactured by FN Herstal in Belgium.^[3] The P90's name is taken from 1990, the year it was introduced.^[2] The P90 was created in response to NATO requests for a replacement for 9x19mm Parabellum firearms; it was designed as a compact but powerful firearm for vehicle crews, operators of crew-served weapons, support personnel, special forces and counter-terrorist groups.^[3][7]

The P90 was designed by FN in conjunction with the FN Five-seven pistol and 5.7x28mm ammunition.^[2] Development of the P90 began in 1986, and production commenced in 1990, whereupon the 5.7x28mm ammunition was redesigned and shortened.^[1] A modified version of the P90 with a magazine adapted to use the new ammunition was introduced in 1993, and the Five-seven pistol was subsequently created as a companion weapon using the same 5.7x28mm ammunition.^[8]

The P90 was developed and initially marketed as a personal defense weapon, but it could also be considered a submachine gun or compact assault rifle.^[9] Featuring a compact bullpup design with fully ambidextrous controls and an integrated reflex sight, the P90 is an unconventional weapon with a futuristic appearance.^[9] Its design incorporates several innovations such as a unique top-mounted magazine and FN's small caliber, high velocity 5.7x28mm ammunition.^[9]

The P90 is currently in service with military and police forces in over 40 countries throughout the world.^[10] In the United States, the P90 is in use with over 200 law enforcement agencies, including the U.S. Secret Service.^[11] The standard P90 is restricted to military and law enforcement customers, but since 2005, a semi-automatic version with a lengthened barrel has been offered to civilian shooters as the PS90.

The P90 was developed by FN between 1986 and 1990 in conjunction with the 5.7x28mm cartridge. FN's goal was to replace the pistol-caliber submachine guns which were in use at the time by military and law enforcement personnel, as it had become evident that such weapons were ineffective against body armor.^[4][13]

Initially the weapon was designed to use a 5.7x28mm cartridge called the SS90, which propelled a 1.5-g (23 gr) plastic-core projectile from the P90 at a muzzle velocity of roughly 850 m/s (2,800 ft/s).^[4] The first P90 prototypes firing this ammunition were created in 1987, and over 3,000 submachine guns were produced in this configuration until 1993, in a low-rate trial production mode.^[14][15] Shortly after its introduction, the P90 was adopted and used in service with the Belgian special forces group in the 1991 Gulf War.^[1]

Following the P90's introduction, FN revised the 5.7x28mm ammunition.^[8] The new variation, designated the SS190, used a projectile 2.7 mm (0.11 in) shorter in length than that of the SS90.^[4] This allowed it to be used more conveniently in the 5.7x28mm FN Five-seven pistol, which was under development at that time.^[8] The SS190 projectile also had a heavier weight, and a more conventional construction with an aluminum and steel core.^[4][8] The first prototypes of the SS190 were created in 1992, and the design was finalized in 1993, replacing the SS90.^[8] A modified version of the P90, with a magazine adapted to use the shortened ammunition, was then introduced in the same year.^[8] Several special cartridge variations were also developed, such as the L191 tracer round and the SB193 subsonic round for use with a sound-suppressed P90.^[5]

Further development of the P90 platform led to the creation of the P90 TR variant, which has a MIL-STD-1913 triple rail interface for mounting accessories. This variant was introduced in late 1999 and continues to be offered alongside the standard P90.^[16] More recently, the P90 has been offered to civilian shooters as the PS90, a semi-automatic carbine intended for personal protection and sporting use