FN Herstal’s P90 submachine gun was developed in the 1990s at the request of NATO, which was seeking a “personal defense weapon” for its troops. The basic idea behind the personal defense weapon, or PDW, was that it would bridge the gap between a pistol and a rifle. A standard 9mm pistol, for example, cannot penetrate body armor, only carries about 15 rounds in the magazine, and has a very limited effective range. A standard 5.56mm rifle, on the other hand, is much larger and heavier to carry around than a pistol, and the 5.56mm cartridge is limited to use in a rifle because it’s too long to fit in a pistol.

With the P90, FNH managed to create a weapon that will penetrate body armor effectively at distances of up to 200 yards, while also being much more compact and handy than a typical full-size rifle. To top it off, the proprietary FN 5.7x28mm cartridge used by the P90 allowed for a larger magazine capacity and was also small enough to be used in a pistol, allowing for ammo commonality (which paved the way for development of FN’s Five-seveN pistol).

This review covers the FN PS90, which is a civilian-legal carbine version of FN Herstal’s P90 submachine gun. Unlike the P90, the PS90 is semi-automatic (hence the ‘S’ in ‘PS90’) and it has a longer barrel. Aside from that, the PS90 is virtually identical to the original military P90, and it’s even produced at the same plant in Herstal, Belgium.



I’ve had a PS90 since 2011, and mine is a USG model, so it has a matte black aluminum optical sight housing and a black aiming reticle. If you plan on using a PS90 with one of the standard factory sight options, I highly recommend the USG sight because it has a streamlined profile and the black reticle itself is extremely well designed. In contrast to the original white FN reticle, the black USG reticle is very easy to see in most lighting conditions. The sight has no magnification, and I think that’s perfect for the PS90’s intended effective range of up to 200 yards.

In normal daylight, the USG reticle consists of three thin, black bars that converge on a small circle in the center, with a tiny black dot in the center of the circle (picture below). The sight also has tritium elements that glow red in the dark, providing an open T-shaped reticle. Lastly, there is a set of stubby backup iron sights on each side of the optical sight housing, in case the optical sight is damaged in some way. Unfortunately, the USG model of the PS90 is no longer produced, but the USG sight itself can still be purchased separately and then attached to a standard PS90.


Disassembling the PS90 is extremely easy and there aren’t any tiny parts to lose. In seconds, the rifle strips down to four main parts groups: the barrel and optical sight group, the moving parts group, the frame and trigger group, and the hammer group. The hammer group is polymer, just like on the time-tested Steyr AUG rifle (as well as the FN F2000 rifle). Meanwhile, there’s even a little compartment in the rear of the stock where you can store a small item of your choice, such as a cleaning kit.

The PS90 is completely unique in terms of both appearance and function. It looks like a futuristic ray gun from a sci-fi movie, and coincidentally, the P90 was popularized quite a bit by its frequent appearances in the Stargate SG-1 TV series. Of course, the PS90 doesn’t just look unique; it contains all sorts of interesting innovations that set it apart. First of all, the magazine itself is a neat patented design that is made out of clear polymer, so you can always see how many rounds are left in it (safety note: the last few rounds aren’t visible as they enter the chamber).


This unique magazine sits on top of the rifle and feeds two sideways rows of ammunition into a circular feed ramp that then rotates each cartridge 90 degrees to put it in line with the chamber. It sounds very complicated and unreliable, but it is in fact pretty simple and the PS90 is extremely reliable, by all accounts. I’ve fired thousands of rounds through the PS90 without any issues of any sort, and that mirrors the experiences of other PS90 owners, as well as the experiences of military and police groups that use the automatic P90 submachine gun.

Another unique feature of the PS90 is the stock arrangement, wherein both of the shooter’s hands hold onto thumbholes in the stock (the big round trigger guard doubles as a foregrip for the shooter’s weak hand). It’s an unusual arrangement but I think it feels very natural. Just like on the P90, everything on the PS90 is completely ambidextrous; it has an ambidextrous safety/fire selector, charging handle, magazine release, etc. Empty cases also eject straight downwards through a chute in the bottom of the stock, so the shooter doesn’t have to worry about anyone being hit with flying brass casings.


As stated earlier, the PS90 fires the 5.7x28mm cartridge designed by FN, which is a small bottlenecked centerfire round that looks like a shortened .223 Remington rifle cartridge. In fact, the bullet diameter is identical to that of a .223 Remington, but the shortened case length allows the 5.7x28mm to also be used in a pistol (namely, the Five-seveN).

As for terminal ballistics with the 5.7x28mm, there is a lot of info out there regarding lethal use of the 5.7x28mm in various shootings, and lots of hunters use the cartridge for hunting hogs and other wild animals, with good results. So we can conclude that the round is an effective option for either self defense or hunting (within limits). FN defines the PS90’s effective range as being about 200 yards, but that might be a bit optimistic, because the round sheds its energy very quickly. The upside to this is that a 5.7x28mm bullet is less likely to cause collateral damage to a bystander in the distance.


Another benefit of the 5.7x28mm is that it has light recoil. I would describe the recoil impulse as being a bit less than that of a 9mm, but definitely more than that of a .22 Long Rifle. It’s very easy to shoot the PS90 quickly and accurately. This also means the gun has tremendous appeal for new shooters or anyone who can’t handle recoil very well (e.g. small women and elderly people). When fired from the PS90, the 5.7x28mm is also relatively quiet (compared to a typical rifle) and has no noticeable muzzle flash, so that’s another plus. Due to the high velocity (2,100 to 3,050 ft/s), bullet drop is limited and that makes it a pretty flat shooter as well.

Picatinny accessory side rails are available for the PS90, and there are all kinds of accessories you can add, including tactical lights, lasers, slings, and brass catchers (all of which I’ve used on the PS90 at one point or another). The PS90 brass catcher offered by FN is a must-have; at $50, it is wildly overpriced (which is typical for FN accessories), but it works pretty well, collecting about 100 5.7×28 cases before it needs to be dumped. If you do plenty of shooting and collect your cases to sell or reload, a brass catcher will pay for itself in no time.


One potential con with the PS90 is the long 16-inch barrel. This is necessitated by U.S. Federal law, which requires civilian rifle barrels to be at least 16 inches long unless registered as NFA weapons. A standard military P90 submachine gun has a barrel length of 10.3 inches and an overall length of only 19.7 inches, which is probably comparable to the screen size on your LCD monitor!

The slightly longer PS90 carbine version can’t match that, but it’s still pretty compact even with the extended barrel, coming in at 26.3 inches overall; and the good news is that the barrel can be chopped down to the original 10.3-inch length if you opt to go through the SBR registration process with the ATF (which is what many PS90 owners have done). The other good news is that, even if you keep the longer barrel on your PS90, it has a higher muzzle velocity than the standard P90 barrel by about 100 to 150 feet per second, which translates into a bit more range and power. The PS90 will definitely blow up a pop bottle or watermelon.




A minor con with the PS90 is the poor trigger pull, which is pretty heavy and clunky, and that’s to be expected with a “bullpup” configuration, wherein the chamber is located at the back of the weapon to reduce wasted space. In the meantime, a lot of modern polymer materials are used in the construction of the gun, which is not all that unusual nowadays. However, the P90 was one of FN’s first weapon designs to incorporate polymer materials, and the weight reduction in this case is particularly impressive.

A fully loaded PS90 weighs only 7.5 pounds, which is similar to what an AR15 rifle weighs empty. A spare loaded magazine for the PS90 weighs about a pound. At the same time, the PS90 carries an impressive amount of ammunition (50 rounds) and the magazine is 100% flush fit. This is, again, due to its unique magazine design and bullpup configuration.

All in all, the FN PS90 is one of a kind. Even today, two decades after the P90’s creation, the weapon is completely unique; and over the years, it’s proven itself to be an effective fighting tool, being used in its original format by hundreds of agencies in over 40 countries.


• Cons:
o Poor trigger pull
o Gun/ammo is expensive
• Pros:
o Lightweight
o Compact
o Ambidextrous
o Easy to disassemble
o Accurate
o Low recoil
o Flat shooting
o Reliable
o Good sights
o Penetrates SBA (depending on ammo)
o Large magazine capacity


Admittedly, the PS90 is a bit on the expensive side and the ammo can be hard to locate sometimes, but you get what you pay for. This is an exceptional firearm with too many innovations to even describe here. The result is a compact, effective rifle that anyone can shoot very accurately with little or no experience. Whether you’re looking for a good hunting rifle for hogs or coyotes, or a user-friendly home defense rifle, or just something fun to play around with at the range, the FN PS90 is definitely an option you should consider.


Manufacturer: FN Herstal (Belgium)
Cartridge: 5.7x28mm
Action: Straight blowback
Overall Length: 26.3 in
Barrel Length: 16 in
Height: 8.3 in
Width: 2.2 in
Weight: 7.5 lb (loaded)
Magazine Capacity: 50 rounds (10 and 30 round magazines also offered)
Muzzle Velocity: 2,100 to 3,050 ft/s (depending on load)
Effective Range: 200 yards

These are specifications for the PS90 rifle. For specifications on the P90 submachine gun, visit the FNH USA product page.

For more photos of the PS90, visit our photo gallery.



David is a Missouri native and a long-time writer, photographer, and gun enthusiast. He is a member of the National Rifle Association, the Second Amendment Foundation, and other gun rights organizations, and works to preserve Americans’ right to keep and bear arms.