In 1989, NATO issued a solicitation to firearms manufacturers for a new Personal Defense Weapon (PDW) to enter service by 2000. The weapon needed to be lightweight and compact yet capable of firing a cartridge that would defeat body armor, which was appearing on the modern battlefield.

fnh2.gifFull-size battle rifles would be cumbersome or unnecessary for rear echelon troops, armor personnel working in tight quarters, officers, etc. For these troops, a small gun firing a round more powerful than a pistol caliber that could be easily slung out of the way was needed. It was the same reasoning that caused our military to develop the M-1 carbine prior to the start of World War II. But the result to NATO’s request bears little resemblance to our old M-1.

Gun Details
In 1990, Fabrique Nationale de Herstal (FNH) introduced their submachine gun (SMG), the P90. Constructed primarily of polymers and alloys for weight savings and utilizing a bullpup design to make the weapon as short as possible, the new design had a number of innovative features in addition to its futuristic looks.

The P90 utilizes a 50-round magazine that adds little bulk to the gun. Users will find that the gun is completely ambidextrous and capable of semi- and full-automatic fire. Chambered for the then-new 5.7x28mm cartridge, the P90 was capable of penetrating body armor with little recoil or muzzle lift. The P90 was lighter and more accurate than most of the SMGs, which were chambered for less powerful pistol rounds. 

In 2004, FNH introduced a companion pistol, the Five-seveN, chambered for the same 5.7x28mm cartridge. Like the P90, the gun utilizes a polymer and alloy construction and possesses a 20-round magazine capacity. Its extreme lightweight and low felt recoil, half as much a 9mm gun, makes it an ideal sidearm for the troop equipped with a P90.

FNH knew that there was substantial non-military interest in the P90, and in 2005, they introduced the PS90, a semi-automatic version of the select fire P90 SMG. Fitted with a 16-inch barrel the gun is completely legal for civilian ownership. I received a sample of the PS90 TR (Triple Rail) carbine that possesses Mil-Std-1913 Picatinny rail so that the user can easily change optics depending on the mission. 

Side rails offer the user the ability to attach accessories like a light and laser. Like the P90, the PS90 is completely ambidextrous and blowback in operation. I also received a sample of the Five-seveN pistol to evaluate alongside the PS90. But before we get started on the guns it is important to understand the cartridge that they both fire.

5.7x28mm Details
Developed by FNH, the bottleneck 5.7x28mm cartridge uses a 28- to 40-grain, depending on the load, bullet of .224 of an inch diameter. Fired at a hyper-velocity, the round has a propensity to tumble when it hits the target, creating a wound the length of the bullet rather than just its diameter. This makes it unlikely for the tissue to collapse upon itself. 

Individual rounds of 5.7x28mm weigh about half of what a 9mm bullet weighs. FNH claims that felt recoil is also about half of what the 9mm is in both the carbine and pistol and after firing both guns, I’d have to say is just about right. A special polymer coating is applied to the brass cases for easier extraction because of the higher chamber pressures and the lack of case taper. Because both guns are blowback in operation this is especially important. This coating also helps the rounds feed more smoothly through the carbine’s and pistol’s magazine.

Perhaps the most innovative feature of the PS90 is its magazine. Constructed from a translucent polymer it sits flat on top of the receiver, under the optics rail. Unlike other weapons, the magazine is not an appendage that adds to its bulk or dimensions. I received a 30-round magazine with the PS90 but 50-round magazines are also available. Additionally, FNH makes a 10-round magazine for those states that restrict the magazine capacity. 

To load the magazine, slide the round under the magazine lips until it locks into position. Loading another round on top flips the cartridge below 90 degrees and moves it into the box’s storage area where the rounds are held under spring pressure in a staggered, double column. Shooters can take a quick glance to see just how many rounds they have left in the translucent polymer magazine. 

FNH’s design is ambidextrous and that is a huge selling point for military and law enforcement issue. Cocking handles, used for charging the chamber, are on both sides of the carbine. The safety is a disk that sits under the trigger and can be easily manipulated by the shooter’s trigger finger. It’s unlike anything I’ve experienced before, but I liked it. It clicks positively into the safe and fire positions and after some practice can be fast to get into action.

Ergonomics played a huge part in the design of the P90 and subsequent PS90. You’ll note that it has what could best be described as a thumbhole stock. Rather than place a vertical foregrip on the gun, FNH used a rounded area for the support hand. Just in front of that area is a bumper that keeps the offhand from going far forward. 

Not a big deal on the PS90 with its 16-inch barrel, but it could prevent some real embarrassment on the SMG should the shooter find his hand in front of the muzzle. While the ergonomics are shooter-friendly, the rounded portions of the fore-end are not conducive to bench rest shooting. Despite this I think that you’ll agree that the PS90 possesses plenty of practical accuracy.

PS90 Range Time
Initially, I had a Trijicon TriPower reflex sight on the gun and fired a number of 50-yard groups. I was so impressed with the accuracy that I ran home and grabbed a Trijicon Accupoint 1.25-4x scope and cranked the magnification up all of the way. Both of the ammunitions that I had produced 5-shot groups of less than an inch. 

While that might be just average for a service-size gun, keep in mind that this lightweight carbine was designed as a PDW and for a gun with its dimensions and proportions, I think that’s phenomenal accuracy. The carbine trigger pull broke at 7.25 pounds. The PS90’s barrel uses a 1-in-9-inch twist barrel to stabilize the lightweight bullets. Its 16-inch barrel features 14.8 inches of rifling and terminates in an integral birdcage flash hider.

To gauge whether there is a substantial advantage to firing the 5.7x28mm PS90 compared to an AR carbine chambered for the 5.56mm round I set up a steel target at a distance of 30 yards. I used a PACT electronic timer to measure the time between shots as I hammered the target first with the PS90 with a TriPower sight attached and then with my 16-inch AR-15, equipped with a Trijicon Reflex sight. 

My splits, or time between shots, with the AR-15 carbine averaged right around 0.50 of a second. Switching to the PS90 my splits dropped to 0.44 of a second. There was noticeably less disruption with my aiming point when firing the 5.7x28mm cartridge. The PS90 equipped with the TriPower reflex sight and a loaded magazine weighed about a 1.5 pounds less than my AR-15 carbine outfitted with the reflex sight and loaded 30-round magazine.

Recently, I shot the FNH SCAR (Special Forces Combat Assault Rifle) Heavy in .308 and SCAR Light in 5.56mm. It only took two rounds in the full auto mode for the .308 to recoil off a silhouette target at about 20 yards. With the 5.56mm SCAR Light I was able to place about three rounds on the target before recoiling off my mark. However, with a true full-auto P90 I was able to empty 30 rounds into the chest of the target. Sure, you sacrifice power by shooting the 5.7x28mm, but the tiny cartridge allows you to place more rounds on target faster.

Five-SeveN Range Time
Weighing just 1.6 pounds, loaded with a 20-round magazine, the FN Five-seveN pistol fires the same 5.7x28mm cartridge that the PS90 does. Like the carbine, the pistol is constructed from polymers and alloys for lightweight and corrosion resistance. Like most modern duty guns the Five-seveN has an accessory rail at the bottom of the dust rail for attaching lights and or lasers. It’s a formidable weapon and makes a nice companion to the PS90 carbine.

Though the pistol’s grip feels somewhat blocky it does not impress me as being terribly oversized. It’s comfortable to hang onto and possesses molded checkering and horizontal grooves to provide a secure shooting grip.

Should you feel that the Five-seveN’s 20-round magazine is somewhat lacking in firepower you can purchase extension kits that are easily installed and increase the magazine capacity to 30 rounds. The Five-seveN’s manual safety levers are located in positions that will be new to most American shooters. 

Levers are located on both sides of the receiver, just above the trigger and can be engaged with the trigger finger or thumb of the support hand. I was more comfortable flipping the safety down with my left thumb as it rested naturally over the safety with a two-hand hold. The magazine release is also reversible.

My Five-seveN sample has a surprisingly crisp trigger that breaks with 5.25 pounds of pressure. This trigger, good sights and light recoil made the Five-seveN one of my favorite guns to benchrest for accuracy. Throughout my testing I do not believe that I ever fired a 5-shot group over 2 inches. In fact, my best groups ran between 1.5 inches and 1.25 inches for five shots at 25 yards. Unfortunately, I only had two different loads to test the gun with but they fired equally well.

To test the Five-seveN in rapid-fire mode I fired double taps at my steel targets at a range of about 12 yards. What I found was that I could hit the 12×18-inch targets twice with an average time between shots of 0.44 of a second. For comparison’s sake I had brought along a steel-framed 1911 .45ACP and my times were about the same. Remember that the Five-seveN is much lighter in weight and also uses a blowback action. While I realize that I was comparing apples to oranges with this exercise, it demonstrated to me that the Five-seveN is a very controllable pistol and possesses light recoil.

Final Notes
While you may not find the PS90 carbine and Five-seveN pistol to be the answer to every tactical scenario you will find them to be accurate and unerringly reliable. Their designs are ergonomically friendly, ambidextrous and lightweight. As for the 5.7x28mm cartridge, you’ll have to be the one that decides if it will provide you with the power required for your needs.

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