FN PS90
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| PS90 | |
|---|---|
 The FN Herstal PS90. |
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| Type | Carbine |
| Place of origin | Belgium |
| Specifications | |
| Weight | 2.9 kg (6.4 lb) empty 3.4 kg (7.5 lb) loaded, 50 rounds |
| Length | 667 mm (26.2 in) |
| Barrel length | 407 mm (16.04 in) |
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| Cartridge | 5.7 x 28 mm |
| Action | Straight blowback, closed bolt |
| Rate of fire | Semi-automatic |
| Effective range | 200 m |
| Feed system | 10, 30, or 50-round box magazine |
The PS90 is a carbine manufactured by Fabrique Nationale, based on their FN P90, that first became available in the civilian market in December 2005.
Contents |
[edit] Overview
The gun is a semi-automatic sporter version of the FN P90 submachine gun, designed for the U.S. civilian market. It is a blowback-operated firearm, firing from a closed breech, with a semi-automatic firing mode. It features an ambidextrous safety selector and cocking handle, along with downward ejection of spent cases. The PS90 is built in a unique bullpup configuration that places the 50-round translucent magazine above the weapon, parallel to the barrel. This design makes the firearm extremely compact and maneuverable and the translucent magazine makes it easy to quickly check the number of rounds left. The PS90 is constructed largely out of weight-saving polymers.
[edit] Mechanical Characteristics
The PS90 has a 16-inch barrel, either an olive drab green or black plastic body (Black PS90s are now in full production) and a MC-10-80 reflex sight identical to that on the standard P90. The MC-10-80 must be removed and replaced by the FN USG M1913 Picatinny rail in order to use aftermarket optics. The USG black reticle MC-10-80 is also available for the PS90 and P90. The barrel rifling has 8 grooves, a 1/9 right-hand twist, with a rifled length of 14.8 inches and a full length of 16.1 inches due to the addition of a fixed "birdcage" flash suppressor. The overall length of the PS90 is 26.3 inches.
The trigger pull is approximately 8 lbf. According to the manual, the trigger pull should be between 25 and 45 N (5.6-10.1 lbf). The cast aluminum receiver assembly is drilled and tapped to accept side Picatinny rails on either side of the main optic for laser or light units. The FN PS90 accepts standard P90 50-round box magazines, but ships with a 10 or 30-round magazine depending on state laws. The circular ramp at the bottom of each magazine re-aligns each round ninety degrees to feed into the chamber.
The hammer group resembles the one found in the Steyr AUG and FN F2000. It is comprised primarily of polymers including the hammer. The breechblock is part of the "moving parts group,” which contains the twin guide rods, rate of fire stabilizer, recoil buffer, firing pin, and AR-15-style extractor and ejector.
The firearm has very low felt recoil. The recoil impulse of 5.7 x 28 mm is approximately one half of 5.56 x 45 mm NATO, while the unique moving parts group further reduces felt recoil through the use of twin recoil springs and the recoil buffer. The felt recoil of the PS90 is comparable to that of a heavy target AR-15 firing .223 Remington. Upon firing the PS90, the barrel itself recoils rearward for about 0.030 of an inch (0.76 mm), enabling the pressure in the barrel to drop to a safe level. The chamber pressure is rated at 50,000 psi for 5.7 x 28 mm FN. Field stripping the PS90 can be done in less than 10 seconds without any tools, breaking it apart into 4 major groups: barrel support/optical sight group, moving parts group, hammer group and the frame/trigger group.
If the operator stores the P90 magazines in a regular magazine pouch, the cartridges can fall out if the magazine is bumped from the bottom. The special FN Herstal P90 magazine pouches have a plastic dust cap that encloses the round part of the magazine. This dust cap can help prevent the cartridges from falling out during high impact maneuvers. However, contrary to popular belief, the magazines are not prone to internal cartridge jams.
[edit] Ring Sights MC-10-80 reflex sight description
The Ring Sights MC-10-80 was designed for the FN P90 from the ground up. It is not compatible with any other platform of firearms. It utilizes a forward aimed fiber optic collector to illuminate the daylight reticle. The daylight reticle consists of a large circle of approximately 180 MOA, with a smaller circle in the center of approximately 20 MOA that contains a small dot of about 1 MOA in the center. The low-light reticle consists of a half-T that is primarily illuminated by a tritium module that glows red/orange. This illumination can easily be observed in a dark environment. The half-T reticle can be seen in the daylight when a strong light source is shined into the rear fiber optical collector. The rear collector was designed to aim up towards the sky to use moonlight or ambient light in the night sky in conjunction with the tritium to illuminate the reticle. Contrary to popular culture and airsoft, the P90 and PS90 factory-equipped Ring Sights reflex sights are not red dot sights.
[edit] Variants
[edit] PS90
The standard PS90 comes in either an olive-drab or black polymer stock along with the standard Ring Sights MC-10-80 reflex sight (white reticule).
[edit] PS90TR
The PS90 Triple Rail, or PS90TR, uses a different receiver assembly that is similar to the P90TR. The standard back-up iron sights are no longer present, and instead the top of the receiver is machined into a Picatinny rail for mounting a variety of optics. Two plastic side-rails are included for mounting lasers or tactical flashlights. The PS90TR is available with either an olive-drab or black polymer stock.
[edit] PS90 USG
The PS90 USG is the same as the standard PS90, except the USG black-reticule reflex sight replaces the Ring Sights MC-10-80. This USG sight is the same as the one found on the P90 USG. The PS90 USG is available with either an olive-drab or black polymer stock.
[edit] Photographs (PS90)
The pictures below are from the PS90. The original P90 is very similar. The main differences are the P90 has: a black dyed plastic frame that has slightly different cuts towards the front, a different safety selector and trigger pack for full auto and single shot capability, a shorter barrel with a different flash suppressor, and a receiver with different back up iron sights.
 PS90, original box, detached 30-round box magazine, and an operator's manual. |
 1. Hammer group, 2. Barrel support and optical sight group, 3. Butt plate, 4. Magazine, 5. Moving parts group, 6. Frame and trigger group |
 1. Receiver lock button, 2. Cocking handle, 3. Ring Sight MC-10-80 Reflex sight, 4. Elevation adjustment, 5. Windage adjustment |
 P90/PS90 magazine release pad |
 PS90 safety selector. Note that it is the opposite of the P90 selector, and does not have "A" for a fully-automatic firing mode |
 PS90 hammer group |
 Rear shot of the hammer group, showing the drop safety. |
 Moving parts group. 1. Rate of fire stabilizer, 2. Extractor, 3. Ejector |
 Moving parts group. 1. Recoil buffer, 2. Firing pin, 3. Recoil guide rods and springs |
 The "Gen 1" flash suppressor is part of the barrel shroud, which is blind-pinned to the barrel. |
 The previously loaded cartridge rotates 90 degrees |
 The daylight reticle is shown here with the reflex sight aimed at a tree trunk. |
 The low-light reticle of the reflex sight. Note that normally it is not this clear or bright. The tritium module should make it glow red/orange. A light is shined into the fiber optic for this photograph |
 5.7 x 28 mm ballistics using a 50-yard (46 m) zero with the PS90 and MC-10-80. |
 5.7 x 28 mm ballistics using a 100-yard (91 m) zero with the PS90 and MC-10-80. |
 Top of the PS90/P90 fired case collector. |
 Spring clamp mechanism of the PS90/P90 fired case collector. |
 The red arrows indicate the spent case impact marks on the hammer group “deflector.” |
 The hammer group is installed in the PS90. The red arrows indicate the spent case impact marks in the ejection chute. |
 The hammer shows slight wear from hitting the steel firing pin and from the breech block pushing it down. |
