FN P-90

Light, fast and deadly, FN’s high-tech subgun is the first firearm designed to take on the environment of the 21st century.

Before we begin our feature on FN’s high-tech P-90 submachinegun, let us be crystal clear: None of the products being shown are available to civilians or even individual police officers. They may only be purchased by legitimate law enforcement entities. The BATF has ruled  that the 5.7x28mm cartridge is “non-sporting” and cannot be sold outside of law enforcement agencies.


In addition to the already common restrictions on machine guns, the companion piece — the Five-seveN pistol — is only available with a 20-round magazine, so it cannot be sold on the civilian market. Those are the facts of life. No matter how cold it is, neither you nor I can privately own a P-90.

Now for a little history. FN began development of a new weapon system about ten years ago with the idea of providing weapons for the 21st-century battlefield. The most significant change in infantry combat was the prediction that individual soldier would be protected by body armor and bullet-resistant helmets.

While the average foot soldier is armed with an assault rifle firing the 5.56 NATO cartridge, support troops who are customarily armed with 9mm handguns or submachineguns firing the NATO cartridge would be at a severe disadvantage and possibly unable to neutralize a threat wearing protective clothing.

It’s not difficult to see a direct parallel between the military and new police situations. Law enforcement confronts suspects wearing body armor with increasing regularity.

Most rifle cartridges, such as the 5.56 NATO (.223) will handily defeat body armor, but they also present a potential hazard of over-penetration. FN’s system is based upon a new cartridge, the 5.7x28mm, which is specifically designed for tissue penetration in the range of 10″ to 12″.

The 5.7x28mm bullet becomes unstable as it penetrates tissue but still possesses enough power to defeat soft armor up to level IIIA. The ball can accomplish this because of its great two-part core.
The forward third of the bullet’s core is steel, and the back segment is aluminum. It is covered by a copper plated steel jacket. Weight is 31 grains. The shift of the center of gravity forward contributes to the instability. The rifling twist of 1:9 is more than adequate to stabilize the bullet at the nominal velocity of about 2,300 fps.
In A Class By Itself
The P-90 looks very different from any other gun. It took a moment to identify what each thing was and what it did. This is especially true of the stock since it places the weak hand only inches away from the muzzle. The ergonomic shape of the stock serves to make it very easy to hold correctly, though, and you never really notice how close your fingers are to the muzzle.

The design of the stock is highly ergonomic and ambidextrous, so it doesn’t take long at all to become intimately close with the gun. Controls are few but conveniently located.

The safety/fire selector is located at the rear of the trigger guard where your trigger finger can easily push it while moving toward the trigger. There are three positions: safe, single, and full auto.

The trigger pull is almost two-stage. A short pull will deliver a single shot, even on full auto; pull it a little further to rock and roll. With only a little experience I found it easy to fire three- or four- shot bursts on demand.

The P-90 is only about 20″ long, yet it has a 9.8″ barrel. This is possible due to the bullpup construction which places the operating mechanism behind your hands.

The P-90’s breach is just below your cheek, but the magazine efficiently blocks any gas or gunk from reaching you. Unlike many blowback weapons, there is entirely no gas or unburned powder to smack you in the face.

The empties are ejected straight down. Gravity is our friend. The case falls free of its weight, and even though it’s odd to feel brass bouncing off your shoes or belt buckle, it’s nice not to have it bouncing off your nose. A bare midriff would be a bad idea.

Tiny And Terrible
We were able to compare the penetration of the 5.7x28mm round when fired into bare, 10 percent gelatin, the same gelatin covered by FBI standard “heavy clothing,” and gelatin protected by a test panel of level IIA soft body armor.

The bottleneck cartridge case is tiny. There is nothing in the American cartridge library that is comparable. The rim diameter is only 0.305,” and even though it carries a full .224″ diameter bullet, it is dwarfed by the better-known .223 cartridge.

The 5.7x28mm case is highly efficient. A powder charge of 6.5 gas. Using a very small-grained ball powder propels the 31 gr. Bullet at a measured 2,329 fps from the P-90’s 9.8″ barrel.

At this time FN is the sole source of ammunition, but an agreement has been reached between FN and Winchester to load the cartridge in this country. Sources report that initial production will be done using components supplied by FN but that Winchester is expected to conduct additional research with an eye toward further development.

The small size of the case makes it possible to get lots of them in a magazine, but the P-90 magazine deserves compliments for more than just its 50 rounds. When you see it, the first thing that may seem odd is that the rounds lie transversely to the bore and feed down. This is contrary to almost everything we’re used to but accounts for much of the gun’s reliability and ease of operation.

The heart of the magazine is the follower who actually works like a turntable. As you load the rounds, the follower turns them 90 degrees, so they lie at right angles to the bore. The magazine is a very simple mechanism with three molded parts and the spring, yet it is easy to load and completely reliable.

You would think putting 50 rounds in any magazine would become a chore somewhere along the way. Not so with this one. It takes little more effort to load the 50th series than it does the first.

Serious Fun
Shooting the P-90 is both impressive and fun. It is surely a serious weapon, but it’s hard to shoot it without a grin. Over the course of two separate sessions, I fired hundreds of rounds through the gun without a malfunction and witnessed a lengthy meeting where a large group of people shot two P-90s. Once more, I saw no stoppages.

Even though the P-90 shoots at rapid 900 rounds per minute (it takes 3.3 seconds to fire a full 50 round magazine) it is imminently controllable. Some of this is due to the mechanics and design, but even more to the nature of the cartridge.

A fully loaded gun weighs just 6.6 lbs. and generates 0.5 ft./lb. Of free recoil energy. By comparison, a 9mm weapon of the same weight would produce about 2.5 ft./lbs. Now neither of these recoil levels are punishing — or even worrisome — but it certainly would seem to confirm the ease of shooting I experienced. Accuracy is not a problem in any case.

A full 50-round burst was easily kept inside 8″ at about 20 yards. At 50 yards, single headshots on an IPSC target were no problem, and at 100 yards five-shot groups were inside 6″. I bet the little cartridge will shoot a lot better than that, but the sights on the P-90 are just not designed for precision shooting.

The sights are more than accurate enough for the gun’s primary mission; the reflex sight’s engraved reticle — a circle with posts at the bottom and either side — is easy to see and fast to acquire. It is illuminated by a tritium element for the night or low light shooting. An optional Picatinny rail is available in place of the reflex sight, and there is also a model with an integral laser.

Mechanically, the P-90 is simplicity personified. It is a straight blowback design with a bolt that rides on a pair of steel rods. It is guided very securely within the frame, which is another reason for the gun’s high degree of reliability.
Field stripping couldn’t be easier. With the magazine removed you’ll see a large metal button; push it and the top section slides forward. The bolt assembly will fall out in your hand, and it’s done.

The top half contains the barrel and sight. Cleaning is easy. The trigger mechanism is located behind the butt plate and can be removed for cleaning if desired, although it is not part of routine field stripping.

One observation was that the little gun is remarkably clean even after hundreds of rounds. Obviously, some of this is due to the ammo, but it is also a credit to the design that does not require very much lubrication to run well. Much of the crud that builds up in automatic weapons is due to too much lubrication. The P-40’s combination of steel and polymer parts just doesn’t need a lot of oil.

New Age Gun
As we enter the 21st century, the face of law enforcement weaponry is bound to change. I can’t begin to predict whether the 5.7x28mm round is going to be the answer to a cop’s prayer, but I do know that it is time to seriously examine the options which are made available by today’s technology.

The P-90 and its companion pistol, the Five-seveN, offer some potential advantages for law enforcement. The P-90 could easily replace a more massive weapon in the armory of individual units, and it’s not too much of a reach to think of street cops armed with the Five-seveN.

It will take a real shift in attitude for something like this to become widely popular. After all, the last 25 years have been devoted to developing hollowpoint bullets that expand reliably, and we’d have to abandon that in favor of a shot that doesn’t expand at all. We’d also have to accept that less penetration may be better than more.

So the news of this story is that a challenge to conventional wisdom is out there. Both the cartridge and the guns that shoot it are very interesting and make good sense in both theory and testing. This deserves careful evaluation by the professional law enforcement community.

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