The FN PS90 bullpup: It came from the 80’s


Perhaps one of the most recognizable firearms of the last half century is the FN PS90. It has appeared in countless films, video games, and other forms of media. The space-gun look of the PS90 sets it apart from most traditional firearms and makes it ideal for futuristic media.

The PS90 is a bullpup rifle, which is enough to differentiate it from most, but its curious design and borderline strange shape give it a uniqueness all its own.

The 5.7Ă—28 cartridge used in the rifle is another anomaly, becoming much more prevalent in the last couple of years. Originally it was an obscure cartridge destined almost exclusively for the top-mounted magazines of the PS90 or the civilian-free model, the P90, which uses a shorter barrel and an auto-sear pack.

For many years, there was nothing like the PS90. It has seen new competition arise in the last couple of years, but for compact high-capacity firepower, only a few could match the little FN.

The industry giant FN Herstal has been a dominant power in firearms since the late 1800s, so it should be no surprise that many firearm developments have come from their factories. Weapons from FN have likely been a part of countless military operations, law enforcement agencies, and of course, civilian shooting activities.

Having grown up with the PS90 constantly before me, I like many others, always dreamed of having one to hold and call my own. So when given the opportunity to spend some time with this diminutive little novelty, I of course, stepped forward.

PS90 Review

The construction of the PS90 is an interesting design, using a polymer clamshell to house the rifle’s metal parts.

The action is a blowback type, typically using strong springs and a heavy bolt carrier. There are two metal shafts that the bolt carrier and spring ride on, anchored at the butt of the rifle.

The front half of the rifle simply slides into the polymer housing and has a spring-loaded button to hold it in place.

One of the more obscure parts of the rifle is the magazine function; the fifty-round magazine sits on top of the receiver underneath the sight bridge. The magazine carries the cartridges perpendicular to the bore axis of the rifle.

As the cartridges are pushed to the rifle’s rear, they are twisted ninety degrees as they come out of the magazine, just in time to be caught by the forward-moving bolt carrier.

Spent cases are expelled through the bottom of the rifle, where a small dust door opens when firing the rifle.
The controls of the PS90 are also, of course, different than most. The small charging handles are located on both sides of the front of the receiver, making the gun perfectly ambidextrous.

The safety is located at the bottom of the trigger and rotates between fire and safe from either side of the trigger guard. The top-side magazine release buttons are pressed in an almost pinching motion as you lift the magazine up and pull it out to the rear.

As I mentioned, this makes the rifle completely suitable to be used by right or left-handed shooters, which is a great thing for service weapons that multiple people use.

The bullpup design of the PS90 makes it very short, and with the short-barreled version, it is even concealable. The fifty-round magazines give you very long strings of fire before needing to reload.

These great features make the PS90 a good option for military and law enforcement professionals. Civilians can and should enjoy these same benefits because this is America, dammit!


I was excited to get the P90 to the range to see how it shot. I was lucky enough to get the restricted model P90 instead of the civilian PS90 (semi-auto). This development would greatly increase the cost of reviewing the gun due to my inability to hold back a full send. The basics of the two rifle models are very similar, so the rest of the review would be relatively the same.

I sourced ammunition boxes from different sources, including American Eagle and FN. With the three fifty-round magazines and several hundred dollars worth of ammunition, I figured I could reasonably determine the function and manual of arms.

I’ve been lucky to shoot several different PWD-type weapons and other short-barreled rifles, so I had a baseline to evaluate the P90.

Short rifles like this are typically used for personal defense, assaulting forces, or something similar. These activities are likely to take place at short distances, so these rifles are usually topped with a reflex or red dot sight to take advantage of the rapid target acquisition they provide. This model came with a small red dot sight already installed, making my selection pretty easy.

After inspecting the rifle, I started the long process of stuffing the magazines with cartridges. The small 5.7 cartridges look similar to a tiny 5.56 cartridge, including a little bottleneck. I snapped one of the loaded magazines into the rifle and started with my shooting regimen.

The snappy blast of the 5.7 was quite evident, mainly when it was only a few inches away from your face. The gun cycled its action rapidly, discharging pretty forcefully the spent cartridges straight down onto the shooting bench below me.

I could feel the short travel of the bolt carrier sliding back and forth in the rifle. Other than that, the recoil was very mild and easy to control. Shooting the rifle at twenty-five yards, it seemed quite easy to keep shots on target.

Transitioning between targets was fast, and the rifle tucked neatly into my shoulder pocket, making it easy to keep on target. The short rifle has almost no room to pivot under recoil, the butt tightly tucked into the shoulder, and the muzzle in front of your support hand doesn’t give it much room to jump around.

The longer barrel of the PS90 might make it even more controllable and provide higher velocity from the same ammunition.

The trigger in the P90 was just as I anticipated. Many bullpups utilize a linkage to operate the sear remotely, and the P90/PS90 is definitely one of those. You can feel the sliding linkage and delayed sensation when pulling the trigger.

To be fair, this isn’t a sniper rifle, so having a flexible trigger pull isn’t a deal breaker for me. For the kind of shooting this rifle was destined for, I think the trigger is perfectly suitable, but it may take some getting used to.

The strange grip design of the rifle also didn’t strike me as ideal. It certainly allows you to control the rifle, though.

I’d like to think there was some kind of “engineer” explanation that would somehow justify why it feels like holding two cups of tea with a trigger in one of them, but I don’t think I’ll ever get that answer. Continue reading here…


  • Extremely maneuverable & compact
  • High capacity magazines for fewer reloads
  • Distinguished service record
  • High-velocity ammunition superior to sub-guns
  • Spacegun
  • Awkward grip angles
  • Traditional bullpup trigger
  • Strange controls take getting used to
  • Ammo goes way too fast


The P90/PS90 functioned flawlessly during my testing process. Before firing the gun, I took it apart to inspect and clean it, giving it just a few squirts of lube before reassembly. The design of the rifle is surprisingly simple, considering what it accomplishes in such a small chassis.

Another one of the interesting design aspects of the full-auto version P90 is the trigger function for automatic fire. When the trigger is pressed enough to fire a shot, you can simply release the trigger for an audible reset, and a second shot can then be fired.

Without switching any selector or switch, you can simply pull harder to get an automatic rate of fire. Essentially you pull the trigger through the semi-auto feature and into the full-auto feature with the trigger fully depressed. An interesting design, for sure.


The P90/PS90 is made to be a personal defense weapon, so we aren’t really looking for one-inch groups at a hundred yards.

But even with its bullpup trigger and a modest red dot sight, it wasn’t hard to keep the rifle on soda can-sized targets at 25 yards.

That may not sound like a ringing endorsement, but I wasn’t expecting impressive accuracy with this short-barreled machine gun.


The overall feel of the P90/PS90 was a little odd for me.

I’m sure that, like most things, it simply takes a moment to get used to, but I think it could be summed up with a comment I overheard myself say to another inquisitive shooter at the range; I think the gun is overrated, if I was going to spend the money it takes to get this rifle, particularly if you plan on going the NFA route, your money would be better spent on something else.

While there is nothing wrong with the rifle, and it works flawlessly as designed, I feel like there are better options.

The P90/PS90 does have a couple of things that are undeniably strong points that could make it the only logical choice for certain applications. If you need long strings of fire with no reloads, or if you absolutely need maximum concealment with rifle firepower, then the P90/PS90 is certainly a contender.



The P90/PS90 utilizes completely ambidextrous controls. And it ejects spent cases through a down-chute behind the trigger-hand grip, so the rifle can be comfortably shot without inhibition regardless of right or left-handed shooters.

Dual charging handles on either side of the rifle are done simply and are subtle enough to be almost missed if you don’t know they are there. The rotating disc of the safety takes a second to get used to, but it does allow for simple operation using either trigger finger.


fn ps90 magazines

The magazines used in the P90/PS90 are one of the more interesting parts of the rifle. The cartridges are stacked perpendicular to the bore line; a turntable at the base of each magazine pushes the cartridge down while rotating it ninety degrees as it comes down. It is an incredibly innovative way to stack a large amount of ammunition in the rifle without reducing its portability.

Magazine changes are a little unorthodox compared to what most of us are used to. The magazines are inserted in the rifle by putting the blind end forward under the sight-bridge, then hinging it down, snapping the turntable into the top of the receiver.

The magazine release buttons are on both sides of the round turntable at the rear of the magazine, when they are pinched together the magazine is easily lifted and removed from the rifle.

While these mag changes might sound a little more intense than you’d like, particularly under life-threatening circumstances, the fact that the mags hold fifty rounds means you will spend more time shooting and less time reloading.

fn ps90


The curious magazine design definitely made FN engineers have to reconsider the sight mounting options for the P90/PS90. They came up with a bridge that goes over the top of the magazine, which also conveniently doubles as a more rigid metal structure to protect the polycarbonate magazines.

Whether you use some short radiused iron sights or a red dot type sight, they can be mounted to the Picatinny rail atop the bridge.


I spent a good portion of the afternoon burning through boxes of ammunition and the rest of my time loading magazines. Most of my time was spent shooting at twenty-five and fifty yards, which seemed appropriate for this little rifle.

Many targets transitioning, mag changes, and reloads were quite helpful in getting more proficient with the P/90/PS90.

I have to admit it is a fun little rifle to shoot. The near-recoilless shooting makes it fun to run quickly across a course of fire. Various targets, including clays and paper, were all easily used for running drills with this gun.

Most of the shooting was done from the standing position, or from a standing supported by leaning against a corner or something similar.

The compact size of the P90/PS90 made it easy to maneuver around the range, and corners and such were easy to negotiate. I also noticed that such a short firearm could also be a little bit more dangerous.

I would have really preferred to pull the muzzle brake to install a suppressor, not just for the noise but to have something else protecting the muzzle. Guns that are this small can get dangerously close to hands and fingers when opening doors and other operations.

If you shoot a shorty like this, watch your hands and muzzle.

The downward ejection of spent cases was a pleasant change from what many of us are used to. The brass is thrown at a pretty good speed, though, so don’t count on finding them all at your feet. The dust door that covers the ejection bay is supposed to snap shut, though the model I was using seemed to have a problem staying snapped in the closed position.

fn ps90 trigger


Both the American Eagle FMJ and the FN branded ammunition functioned great.

Most people would want to use expanding bullets instead of FMJ ammunition, especially for defense purposes. I have heard that some folks have experienced issues with inexpensive 5.7Ă—28 ammo, but I did not have that experience.



The P90/PS90 functioned without any malfunctions during testing


I didn’t care for the grip design of the PS90; your experience may differ


The PS90 rifles don’t have a lot of customization as far as I can tell, other than sights. Even the muzzle device wasn’t changeable.


As I mentioned from the beginning, the PS90 is iconic in its looks, but looks aren’t everything

VALUE (6/10)

I gave the PS90 a low score simply because there are more affordable firearms that do nearly the same job.


I guess you could say overall, I was just a bit let down by the P90/PS90. Kind of like with the Steyr AUG. As an eighties kid, you grew up thinking these were the coolest guns ever. But in real life, you pick them up, and they seem to be sort of a novelty.

Like I said, there are some specific situations where the PS90 could stand alone with no competition. But I think the scenario where I need long strings of fire with a slow rifle cartridge at close range from a gun I could hide under my coat just doesn’t seem reasonable.

I suppose if you’re in the Secret Service or something, there may be a good purpose, but for the average gun enthusiast, I think it’s more of a conversation piece, like 50 BMGs, Desert Eagles, and any of the Mac pistols.

Something you could pull out to impress company, but not something you’d shoot a lot regularly. It does fascinate me that to this day, the PS90 still looks as space-gunny as anything else, a gun before its time, perhaps.


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