An In-Depth Look at the FN PS90

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Editor's Note:  This article was originally posted to the site on Sunday, 16 March 2008 by Doc Random
 

Fabrique Nationale de Herstal, or National Factory of Herstal to those of us not well versed in the French language, is one of those multi-billion dollar firearms companies that the average shooter may have never even heard of. Commonly known as FN, the company has assets in the USA, and manufactures guns under the Browning (since the brand’s inception) and Winchester (since 1989) names. FN is headquartered in (the French part of) Belgium, just outside the city of Liege. Unlike quite a few other firearms companies in Europe, FN actually started out as a gun factory. Since its inception in 1889, the company has gone on to produce such all-time greats as the FN FAL, the P35 (Browning) Hi-Power, and the M240-series medium machine guns currently in use by the US military.
FN is one of those often overlooked major contributors to the advancement of firearms technology. The guns developed and marketed by the company have helped shape the face of modern warfare, while also making a significant contribution to the civilian small arms market. Even in today’s “gun-unfriendly” political climate, FN continues to keep its civilian customers as a core part of its business strategy. As such, the company regularly brings civilian versions of its most technologically advanced guns to market. Because of this, we all benefit from the reduced weight of new materials, the increased efficiency of modern cartridges, and the lower cost and higher reliability of new gun platforms. Yes, the hunter does benefit from all of these “scary” looking “assault” rifles. Instead of humping a 10-pound scoped delicate bolt gun through the desert, he/she can now tote a compact, 6-pound gun that is just as accurate (for practical purposes, of course) and will probably still work after being thrown off a cliff!
The FN PS90 is just one example of the many hot new items FN has offered to us in recent years.

A BIT OF P90/PS90 HISTORY

By the late 80’s, it became evident to many militaries and law enforcement agencies that pistol-caliber carbines were losing their effectiveness against adversaries equipped with the most modern lightweight body armor. While small rifles chambered in 9mm Luger allowed their users to minimize their “load out” weight and size envelopes, the guns left a lot to be desired in the performance department. Yes, you can use the same ammunition in your pistol as you can in your Heckler & Koch MP5 – but the rifle’s slightly longer barrel length and full automatic fire capability only gave moderate increases in effectiveness.
The FN P90 Personal Defense Weapon was developed in Herstal between 1986 and 1987. The gun was designed in conjunction with the 5.7x28mm cartridge, and a pistol (the FN FiveseveN) which fires the same ammunition came some years later. The primary design objective was essentially to introduce a modern replacement for the pistol-caliber carbine. This carbine would be just as lightweight, have select-fire capability, and deliver a high-velocity, lightweight round capable of doing a number on light body armor.
The gun that resulted was nothing short of…well… futuristic. It was created with the use of modern (for the 80’s, anyway) materials and design techniques. Largely made of polymer, the gun held a 50-round top loading magazine, was extremely compact, and even included an integrated reflex sight. Hello, end-of-20th century! It is quite the modern take on the venerable bullpup carbine design.
The most controversial part of the P90’s design is the ammunition it fires. To the well-informed, the 5.7x28mm cartridge is simply a cut-down 5.56x45 (.223 Remington) cartridge. The latter, used every day by hunters stalking tiny to medium-sized game (like prairie dogs and other varmints) is also NATO’s “go-to” cartridge for the individual soldier. US politicians heard about the armor piercing capabilities of the new cartridge and basically declared them “cop killer” bullets. What our esteemed members of congress declined to tell the American public was that MOST rifle bullets with high ballistic coefficients and moderate velocity will also pierce light body armor. I digress.
We won’t get into the effectiveness of the round in this article – but simply to establish a baseline for those unfamiliar with the 5.7x28, just think “it’s half of a .223”. The previous statement isn’t 100% true, but it’ll do for now. Some of the 5.7mm bullets used in commercially available loadings are merely lighter .224 bullets, and can also be loaded into .223 cartridges. The size and weight savings allowed FN to pack 50 rounds into a small magazine, and the 5.7’s lack of heavy case taper allowed them to design “stick” magazines instead of “banana” shaped ones.


The P90’s development represented a nice leap forward in the compact rifle market. And much to our delight, FN began selling a civilian-legal semiautomatic version in 2005. This rifle is appropriately named the PS90.

THE PS90 IN DETAIL

The PS90 differs from its submachine gun counterpart in two ways. First, the happy (full auto) switch and capability has been removed, and the barrel was lengthened to 16.1” in order to meet US regulations on minimum barrel length (16”) and minimum firearm length (26”). Other than that, the gun is pretty much the same as a P90. This is why we love FN.
I purchased my PS90 from John at countryboyartillery.com. He was able to order one of the guns that FN sold at a significantly reduced price from a national distributor. Compared to the going rate, I bought this gun for a song.

The FN PS90, shown with an aftermarket triple rail

The FN PS90, shown with an aftermarket triple rail

First Impressions

The 16.1 inch barrel adds a small amount of weight to the overall package, but the total is still only 6 lbs, 9 oz. The overall length is 26.25”, which is plenty compact for most uses. This is one futuristic-looking rifle, and the fact that it ejects spent cases downward makes the rifle completely ambidextrous.

The 5.7x28mm Round

From left to right: 22LR, 22Mag, 5.7x28mm, 223 Remington, 9mm, 40S&W, 45ACP

From left to right: 22LR, 22Mag, 5.7x28mm, 223 Remington, 9mm, 40S&W, 45ACP

 

A lot of time has been spent comparing the 5.7x28mm round to its parent cartridge, the .223 Remington. Considering the intended use of the round is a replacement for the 9mm in certain situations, it would be best to look at the cartridge in relation to its pistol brethren.
The average 115(?) grain 9mm round weighs approximately 12 grams. The 230 grain 45ACP comes in at a whopping 20.9 grams! The 27 grain 195 weighs in at a svelte 6.1 grams. In layman’s terms, 50 5.7x28mm cartridges weigh about 85% of what a loaded 30-round magazine for an MP5 would weigh! This is a significant increase in firepower with a weight advantage. It doesn’t get any better than that.

The 5.7x28mm weighs approximately half of the round it is designed to replace in the PDW role

The 5.7x28mm weighs approximately half of the round it is designed to replace in the PDW role

Magazines

Three different magazine capacities are available for the PS90. 10-round mags are available for states that limit magazine capacity. 30-rounders are the standard non-restricted magazine capacity, and ship with all the newer civilian-legal PS90s. I don’t know why this is, but I would suspect that it has something to do with staying on the right side of public perception. The original 50-round P90 magazines are also available, and fit the PS90 with no modifications. 30-rounders can be converted to hold 50 cartridges, but the 10-round magazines are fused so as to prevent modification.

50-round PS90 magazines shown with Hornady-tipped SS197 ammo. Notice the first round is at a 90 degree angle to the others in the magazines

50-round PS90 magazines shown with Hornady-tipped SS197 ammo. Notice the first round is at a 90 degree angle to the others in the magazines

The magazines are made of smoke-colored plastic, and are translucent enough to see how many rounds are left. Loading the magazines is easy. The rounds are inserted into the magazine similar to the way one would load any traditional box magazine. As the rounds are added, they rotate 90 degrees and orient themselves in a double stack configuration inside the “box” of the magazine.

SS195 (white box) and SS197 (blue box) ammunition are shown here

SS195 (white box) and SS197 (blue box) ammunition are shown here

To insert a loaded magazine onto the gun, simply slip the “bottom” of the magazine under the rifle’s sight, and drop the open end down into the top of the rifle.

The PS90's magazines simply 'drop in'

The PS90's magazines simply 'drop in'

The magazine release is under the index finger

The magazine release is under the index finger

A look into the magazine well from above

A look into the magazine well from above

Field Stripping

When I first saw the 10 screws holding the housing together, I thought “cleaning this thing is going to be a pain”. Luckily, I could not have been more wrong. The PS90 field strips into its 4 main groups (Barrel, Moving Parts, Hammer, and Housing) in fewer than 2 minutes with no tools required! The procedure goes as follows:

First, press the Barrel Release button. Slide the barrel off the gun.

With the barrel removed, you can now slide the Moving Parts Group off the gun.

The Moving Parts Group contains the bolt and the recoil assembly

The Moving Parts Group contains the bolt and the recoil assembly

Removal of the Moving Parts Group unlocks the Butt Plate. From there, you slide the Butt Plate up…

Sliding the buttplate off the gun reveals the Hammer Group inside the buttstock

Sliding the buttplate off the gun reveals the Hammer Group inside the buttstock

And then, simply remove the Hammer Group. You are now done!

Left - Notice the round indentation on the buttplate cover - the Moving parts Group actually fits into it, holding it stationary. Right - The Hammer group is largely made of polymer

Left - Notice the round indentation on the buttplate cover - the Moving parts Group actually fits into it, holding it stationary.

Right - The Hammer group is largely made of polymer

Sights

The stock reflex sight leaves quite a bit to be desired

The stock reflex sight leaves quite a bit to be desired


My rifle came equipped with the stock reflex-type sight. It’s basically a “dot in a circle” type sight with no magnification and an integrated tritium vial for low light sighting. The reviews I’ve read on this sight indicated that it was barely adequate, so I decided to install an aftermarket tri-rail so I can use other optics. FN also ships the PS90 with its own triple-rail Picatinny-style interface, but that model happened to be significantly more expensive at the time of purchase.
I purchased a T-marked rail interface for the PS90. It was significantly cheaper than using the factory parts.

The aftermarket triple rail is T-marked

The aftermarket triple rail is T-marked

The rail system installs on the same mounting points as the stock reflex sight. The switch did not go off smoothly, though… as always; you get what you pay for. The aftermarket rail required a bit of work with a file to align with the screw holes.

The hole in the rail needed opening up to match the hole pattern of the PS90

The hole in the rail needed opening up to match the hole pattern of the PS90

Once the new rail was fit, I tried out a Chinese-made 3-9x40mm riflescope, and a BSA red dot sight. Both fit fine with a little adjustment.

Carry Cases

A cool gun deserves its own ride to the range, right? So, I picked up an Uncle Mike’s 33” tactical case. The case is about the right size for the PS90, but not for the magazines. Due to their length, they did not fit in the sleeves on the outside of the case.

The gun fits fine..but the magazines are too long!

The gun fits fine..but the magazines are too long!

Mil-Force.com sells a 2-mag pouch that is designed to be worn on a belt. It has leg ties to keep it from flopping around, and also has a quick-release. I found that the pouch fit nicely inside the Uncle Mike’s case with room to spare.

Now, it’s off to the range with my new toy

Now, it’s off to the range with my new toy

ON THE FIRING RANGE

My first trip to the range was merely a “get the feel of the gun” trip. I brought 100 rounds each of SS195 (lead free FMJ) and SS197 (sporting, blue tip) to try out.
I also brought along a Ruger Mini-14 Ranch Rifle and a Galil Golani Sport for comparison. Both of the .223 rifles were shot at 50 yards using the standard irons.

The Mini-14 gave minute-of-man accuracy at 50 yards with irons

The Mini-14 gave minute-of-man accuracy at 50 yards with irons

The Galil rifle is quite fun to shoot

The Galil rifle is quite fun to shoot

Next, I mounted my Chinese-made Norinco scope on the PS90, and attempted to get the gun on paper at 50 yards. This was easier said than done – my groups were “off the paper” low, so I pulled the target back to 25 yards just to find the paper. After “walking” the groups up to the center of the paper, I moved the target back to the 50-yard mark. As a side note, the rear of the aftermarket tri-rail was quite low, and I almost maxed out my adjustment on the scope to bring the rounds on target. A shim would’ve been nice to have in this situation.

Notice the groups 'walking up' the center of the target as I zeroed the scope

Notice the groups 'walking up' the center of the target as I zeroed the scope

While firing through my ammo stash, I noticed that the PS90’s recoil characteristics were both lighter and “crisper” than the pair of .223 rifles. The plastic trigger had a good feel, with what I would call a medium-weight pull and a crisp release. The spent cases exit the weapon at the bottom, just forward of the “buttstock” section of the rifle. This is a boon for both reloaders and left-handed people.

The PS90's cases eject into the black shellcatcher bag. Really nice...

The PS90's cases eject into the black shellcatcher bag. Really nice...

Once I got my rounds centered on the target at 50 yards, I continued to fire off the remainder of the 200 rounds I brought with me. The next 50 rounds were fired both seated and standing. All went without a hitch, and with very good accuracy given the rate of fire.

The group in the center at 50 yards is indicative of the PS90's ease of 'getting off a decent shot' without trying too hard

The group in the center at 50 yards is indicative of the PS90's ease of 'getting off a decent shot' without trying too hard

The final 100+ rounds were fired at a fairly rapid rate, just to get a feel for the gun’s characteristics in a combat or (extreme) defensive situation. After this string, I was actually able to put my hand on the barrel! The 5.7x28mm rounds in the PS90 impart much less heat than the 223 rounds in the Mini-14 or the Galil. In fact, I could probably fry bacon on a Mini-14 barrel after 60 rounds. The PS90 stays cool, and the shot placement stays consistent.

SUMMARY

Overall, I am very happy with my purchase of this rifle… particularly since I heard the price went up more than $300 since I bought it! I am left handed, and have wanted a left-hand or ambidextrous rifle for quite some time. The PS90 is an excellent choice.

As a parting shot, I’d like to note that the controversy over the 5.7x28mm round seems misguided. Different rounds have different compromises. This particular round lets you carry 150 high-energy rounds in 3 magazines, with the same total weight as 75 rounds of 9mm. The only tradeoff is a bit of lost effectiveness vs. the heavier .223 round. That’s a compromise I’d be glad to make.