The FN PS90: Initial thoughts, observations and range report

[Dragonfly]

I have been a fan of FN’s odd bullpups ever since I bought my first FS2000 in 2010. After a few years kicking around the idea of getting a PS90, sort of the FS2000’s little brother, I finally picked up this "used but in good condition" one this week. No better way to kick off Canada Day weekend last night with a shake-down visit to the range to try out a new gun.

But first—a little background. The full-auto version of the PS90, the P90, has been in production since 1990 (I can remember using the PS90 in the video game “Goldeneye” for the N64 in the late 1990s), but I was surprised to learn that the PS90 has only been available for sale since 2005. FN developed the 5.7X28mm ammunition specifically for use in the P90 and FiveSeven pistol (hmmm….might have to keep an eye open for one of them next). Speaking of the 5.7X28mm round—I was surprised by how small it is. Here’s one compared with a 5.56X45mm and a 7.62X51mm round:

The first thing I noticed about the rifle was how many features it shares with the FS2000, which was launched 11 years after the P90.

Even disassembled, you can see the similarities—the main components (barrel group, breech block assembly, stock, and removable trigger group.

Disassembly of the PS90 is surprisingly easy—the video below shows the process.


The trigger packs are quite similar too—here’s the PS90’s

and the FS2000’s:

The PS90 is blowback, while the FS2000 uses a gas-driven piston operation—here’s a close-up of the breechblock (the “moving parts group” as FN calls it)

Those protrusions on the breechblock fit into recesses in the chamber areas:

Instead of the FS2000’s forward ejection, the PS90 ejects straight down (with some vigor, I might add!) The ejection chute is directly below the chamber area.

It has a dust cover you can pop close to keep crap out—it’ll spring open as soon as the gun’s fired.

Operation of the PS90 is completely ambidextrous—the charging handle and mag release are identical on both sides. The charging handle is quite small, easy to work (that’s it, right above the second nut).

The safety is in the trigger guard, just below the trigger.

The magazine release is operated by pushing rearwards and lifting the mag out—it’s not super fast, although with an intended capacity of 50 rounds it was probably felt by the designers that rapid mag changes were a less-necessary feature.

The magazines are a really cool (and heartbreaking for Canadians) design. For a 50-round magazine they add very little to the bulk of the PS90, and nothing to the height. They work in a neat way, too.

Here’s an empty magazine. The PS90’s magazines feed from the rear, well behind the trigger. At first glance, the tendency is to put the round in backwards—that’s probably why there’s a handy diagram showing the correct orientation of the round just to the left of the mag’s mouth.

Here it is with one round inserted:

Now, when you add second and subsequent rounds the previously-inserted ones rotate to become perpendicular to the mag body. In this picture here with two rounds loaded you can see the bottom of the first round at the 6 0’clock position of the circular areas of the magazine.

One big, big drawback to the PS90 in Canada is that, although the SBR version is relatively easy to get (it’s legally categorized the same as a handgun) we’re limited to a measly five rounds in the magazine—here’s the magazine loaded to full Canadian-legal capacity of 10% of its intended use. This was the main reason I waited so long to pick one of these up. It’s enough to make a grown man cry.

Apparently (and I didn’t realize this until I was researching the purchase of this PS90) FN has made various versions of the PS90 with different sighting arrangements. The first version only had iron sights, while mine (the “Triple Rail”) has a mounting rail integral with the upper receiver. Current ones, I think, have a higher rail with integral iron sights. I think I’d prefer the lower-profile rail on mine.

 

[Dragonfly]

I had a chance Friday evening to take the PS90 out for a quick run through at 25m, 50m and 100m. Blackflies are done for the year but mosquitos were out in full force! After a few sighting-in rounds I tried two groups of five at 25m just to see how it’d work.

Not bad but not great. The trigger is very reminiscent of the FS2000 trigger—fairly long and heavy—but while the FS2000’s has noticeable feel just before the break (which allows you to “stage” your shots somewhat) the PS90’s trigger lacked it, and made it tougher.

I tried a few rounds at a faster pace—twelve rounds at the middle target and five at the lower right. The five round capacity is certainly a pain so I was loading one round from a magazine then inserting a five round magazine to at least have six rounds.

I was surprised by the recoil—it’s almost nothing of course but there is a certain “sharpness” to it, I’m thinking maybe from the cycling of the fairly heavy breechblock.

I tried ten rounds at 50m, standing. I was getting used to the trigger by now.

Finally, more for fun than anything else, I thought I’d try 5 rounds from the bench at 100m.

That’s a 3.25” group—I was really surprised! I can hardly shoot my FS2000 or CTAR that well. I was really impressed—with a 2MOA red shot and the first time shooting at 100m. I forgot to mention earlier than my PS90 had its original 16” barrel replaced by a custom 10.3” one by the previous owner (as well as the AAC Blackout flash hider).

The video below shows all the fun (and bugs)


So, what do I think? Well, it’s cool and fun to shoot for sure, and I like its quirky designs—although I am a sucker for oddball guns. It’s surprisingly accurate too. But those damn five round magazines…even if they were easier to swap it’d be more fun. As it is, it’s more of a fun curiosity than a gun that will get a lot of use. Still glad I picked it up, though—It’s a great little brother for my FS2000!

 

[Panzerschwein]

That is so sad that you are only allowed 5 rounds.

 

[grampajack]

I too remember the RCP90 from Goldeneye.

That's probably why I've always had a fondness for PS90s. I think it's one of the coolest guns ever made and 100 years from now will probably be a highly coveted collector's item. Unfortunately it fell flat on its face as a practical weapon, which is probably why FN finally did release it to the civilian market. I suspect they're about to wrap up production. They've discontinued all but one option (black w/ pic rail sight), as well as discontinued all accessories, and replacement parts haven't been shipping for several years now.

The trigger group was actually borrowed more or less directly from the Steyr AUG, which had been around since the 1970s and was by that time a proven design. It's a really handy setup in full auto, and makes infinitely more sense on the PS90 than on the AUG. It basically allows the user to keep it in full auto all the time, and still be able to make the occasional precise shot at long range if and when necessary. Makes perfect sense for an SMG that's going to be used primarily in full auto, especially since the P90 has a range of well over 100 yards.

Unfortunately the round was just too anemic to be practical. Even at point blank on a bare target there wasn't enough penetration to reliably get the job done. FN made two defensive cartridges for it, both of which would fail the FBI test miserably. The standard one is the SS198LF, and you're lucky if you get 8'' in bare gell; and the armor piercing variety is the SS190, and you're lucky to get 10'' in bare gel, though it is pretty much blind to soft armor. It's all the more tragic because the high velocity of the round does quite a bit of damage. If they could just squeeze a few more inches out of it then it would be a thing of beauty. I would be happy with 15'' in bare gel, as that's what your average 9mm HP is capable of.

I think part of what killed it is that the NATO solicitation for which it was developed required that it share ammunition with a pistol directly, necessitating that the round be safe in blowback operated weapons. Even then, however, the pressure is so high (~52k psi I think) that they have to coat it in lacquer to get reliable extraction, and even then extraction problems have not been unknown if the chambers aren't kept meticulously.

What would be truly spectacular is if FN would redesign it as a dedicated rifle/smg hybrid with no concern for being usable in a pistol. That would allow them to make it slightly more powerful, and also to increase the pressure limit. Then redesign the P90 to operate from a locked bolt, which would lighten it considerably, and of course get rid of that ridiculous ring sight system and simply go with a low pic rail. I think they could get adequate penetration without increasing the overall dimensions by very much, and probably get better wound ballistics in the process. You would still have the 50 round mag, the bottom ejection, the non existent recoil, etc. Actually, with a locked bolt, recoil would probably be reduced to literally nothing, allowing the user to get extremely tight groups in full auto. It would be the ultimate door kicker carbine for sure. But, alas, that will never be.

 

[Zerodefect]

Noone runs the stock sight. I have an Eotech on mine.

Making the round more powerful defeats the point of this rifle. Low recoil, low pen. Security, SS, indoor defense in busy areas, more range than a 9mm MP5, but less liability for stray rounds. We have AR's if we want power, and/or the FS2000.

 

[Dragonfly]

The trigger group was actually borrowed more or less directly from the Steyr AUG, which had been around since the 1970s and was by that time a proven design. It's a really handy setup in full auto, and makes infinitely more sense on the PS90 than on the AUG. It basically allows the user to keep it in full auto all the time, and still be able to make the occasional precise shot at long range if and when necessary. Makes perfect sense for an SMG that's going to be used primarily in full auto, especially since the P90 has a range of well over 100 yards.

Thanks for posting that picture--I've never seen an AUG trigger pack before.

 

[chicharrones]

Nice collection, Dragonfly.

I don't own either the PS90 or the FN2000, but my regular shootin' buddy does own them and he allows me plenty of trigger time on both. Out of the two, I like the PS90 the best. The FN2000 just feels unnaturally portly to me, but that's likely due to me growing up with non-bullpup rifles.

The PS90 on the other hand, fits me better. Plus, we can have full magazines of ammo down here in Tejas. Of course, we get the longer barrel, but 50 rounds in the magazine sure is reassuring in what my shootin' buddy calls his "room broom".

 

[grampajack]

Noone runs the stock sight. I have an Eotech on mine.

Making the round more powerful defeats the point of this rifle. Low recoil, low pen. Security, SS, indoor defense in busy areas, more range than a 9mm MP5, but less liability for stray rounds. We have AR's if we want power, and/or the FS2000.

That was never a selling point for the P90, and in fact the reason why it's few users have mostly dropped it. 10'' in bare gel with FMJ isn't overpentration by any definition. I'm not saying make it go through steel armor, just get it to where it can pass the FBI test. And again, if it operated from a locked bolt the recoil would be reduced even if it were made slightly more powerful. The bullet would still be 28-34gr, it would just be going slightly faster. As it is, what little recoil you feel with the P90 is from its massive bolt.

There are still plenty of advantages of the P90 over an AR or FS2000. The overall length, girth, capacity, etc. The weight of ammunition is also a plus, and by switching to a locked bolt you could make the gun itself much lighter than it is. Due to the extreme pressure, the bolt is close to half the weight of the gun to contain it. It's pretty crazy to have a direct blowback cycling a rifle pressure round. Besides, to make a carbine anywhere near the length of the P90 we're talking about a 7'' barrel, and by that time you're dealing with 5.7mm level ballistics anyways, so it's a major case of diminishing returns.

 

[tcj]

If someone gave me cheap ammo for it I would definitely have the P90 - shot a rental several times @ the range and it is a great rifle. BUT ammo is not cheap and I no longer enjoy reloading bottleneck cartridges regardless of caliber - too much on the hands.

 

[barnbwt]

Problem with pure gel penetration is mass. To get 15" you need a much, much harder bullet driven even faster that *really* won't work from the handgun barrel (see 4.6x30) and is even more prone to icepick wounds in soft targets, or a higher sectional density with either more needlelike bullets (see 4.6 again) that are prone to barrel erosion & pressure spikes (no blowback) or heavier bullets like the 40gr SS198 which drops velocity below barrier blind speeds unless pressures are crazy high & require fancy/expensive locking systems (see 4.6x30) and increases recoil rapidly (to something more like Hornet or 22 Spitfire). The 5.7 was brilliant since it met the very difficult design request with a fairly simple & inexpensive solution. For the self defense scenario, military or civilian, it is quite close to ideal. Probably close enough, in fact, to warrant no further significant development of the cartridge (the platforms and bullets can of course still benefit from modern advances in ergonomics and projectile engineering)

I personally like the Spitfire concept, but recognize the added size and power it carries makes a true intermediate round like 5.56 in an SBR a more logical choice. As an alternative to 9mm, a 1/8" shorter but slightly wider (32acp case head) 5.7 round loaded similar to the x28 *could*, but probably wouldn't, be nicer as a pistol/carbine solution.

TCB

 

[Zerodefect]

That was never a selling point for the P90, and in fact the reason why it's few users have mostly dropped it. 10'' in bare gel with FMJ isn't overpentration by any definition. I'm not saying make it go through steel armor, just get it to where it can pass the FBI test. And again, if it operated from a locked bolt the recoil would be reduced even if it were made slightly more powerful. The bullet would still be 28-34gr, it would just be going slightly faster. As it is, what little recoil you feel with the P90 is from its massive bolt.

There are still plenty of advantages of the P90 over an AR or FS2000. The overall length, girth, capacity, etc. The weight of ammunition is also a plus, and by switching to a locked bolt you could make the gun itself much lighter than it is. Due to the extreme pressure, the bolt is close to half the weight of the gun to contain it. It's pretty crazy to have a direct blowback cycling a rifle pressure round. Besides, to make a carbine anywhere near the length of the P90 we're talking about a 7'' barrel, and by that time you're dealing with 5.7mm level ballistics anyways, so it's a major case of diminishing returns.

Sure it was.

It was designed to replace the 9mm HK Mp5, be able to pierce a UN blue helmet at 200 meters (lol), and stop quickly in normal walls, at least much quicker than 9mm.

The 5.7 round was never going to burn through gel. And this is a text book case of when ballistic gel fails us. That weak round drops a pig just fine. Not my 1st choice, but if it'll drop a 300#+ pig, it'll drop me easy.

And it's easy enough to reload if you really, absolutely need to hit that 12-14" pen number in gel.

 

[grampajack]

Problem with pure gel penetration is mass. To get 15" you need a much, much harder bullet driven even faster that *really* won't work from the handgun barrel (see 4.6x30) and is even more prone to icepick wounds in soft targets, or a higher sectional density with either more needlelike bullets (see 4.6 again) that are prone to barrel erosion & pressure spikes (no blowback) or heavier bullets like the 40gr SS198 which drops velocity below barrier blind speeds unless pressures are crazy high & require fancy/expensive locking systems (see 4.6x30) and increases recoil rapidly (to something more like Hornet or 22 Spitfire). The 5.7 was brilliant since it met the very difficult design request with a fairly simple & inexpensive solution. For the self defense scenario, military or civilian, it is quite close to ideal. Probably close enough, in fact, to warrant no further significant development of the cartridge (the platforms and bullets can of course still benefit from modern advances in ergonomics and projectile engineering)

I personally like the Spitfire concept, but recognize the added size and power it carries makes a true intermediate round like 5.56 in an SBR a more logical choice. As an alternative to 9mm, a 1/8" shorter but slightly wider (32acp case head) 5.7 round loaded similar to the x28 *could*, but probably wouldn't, be nicer as a pistol/carbine solution.

TCB

Handloaders can get 12-13'' out of it using custom powders, and pass the FBI test with flying colors. The only problem is that the pressure is so on the edge that you hear about bulged cases and non compatibility between the P90 and FiveSeven. If going up to 62kpsi were an option it would be no problem getting 12-15'' in gel with the standard SS190 pill. People spend so much time thinking up reasons why something isn't possible that they forget to look and see if anyone has actually tried it.

Sure it was.

It was designed to replace the 9mm HK Mp5, be able to pierce a UN blue helmet at 200 meters (lol), and stop quickly in normal walls, at least much quicker than 9mm.

The 5.7 round was never going to burn through gel. And this is a text book case of when ballistic gel fails us. That weak round drops a pig just fine. Not my 1st choice, but if it'll drop a 300#+ pig, it'll drop me easy.

And it's easy enough to reload if you really, absolutely need to hit that 12-14" pen number in gel.

That was never a requirement of the design, just what came naturally as a consequence of the limitations of having to make it cross compatible with a pistol. Its original intent was for mechanized units, engineers, signal, etc. The objective was to give them as much firepower as possible in a compact package. Only after it was deemed too weak for those purposes did it pick up some users in law enforcement who may or may not have been drawn to it by its low penetration. But those users, whatever their initial reason for adopting it (probably just because it was the latest and greatest at the time), dropped it because it was too weak, namely the Secret Service. There's simply no situation where failing the FBI bare gel test is a good thing for anyone.

 

[Danoobie]

I got the PCC. The Five-seveN is very light, easy to draw, and downright enjoyable to carry, for a full size pistol.
I'm finding the PS90 to be a little slippery, but it shoots well. I'm waiting for them to come out with a better sight
system, that's a lower profile. Of course, it's nice when you can use the full capacity mags the gun was made for.
IMO, the FN PDS PCC combo would be a great deal, if it were priced better..

 

[grampajack]

I got the PCC. The Five-seveN is very light, easy to draw, and downright enjoyable to carry, for a full size pistol.
I'm finding the PS90 to be a little slippery, but it shoots well. I'm waiting for them to come out with a better sight
system, that's a lower profile. Of course, it's nice when you can use the full capacity mags the gun was made for.
IMO, the FN PDS PCC combo would be a great deal, if it were priced better..

What are you using? I got one of the newer ring sights and it's perfect for me. It was way overpriced, but I couldn't be happier with it.

 

[browningguy]

If someone gave me cheap ammo for it I would definitely have the P90 - shot a rental several times @ the range and it is a great rifle. BUT ammo is not cheap and I no longer enjoy reloading bottleneck cartridges regardless of caliber - too much on the hands.

I've been able to buy ammo for $16-17 a box of 50 over the past couple of months, that's not very expensive in my book.

 

[Dragonfly]

I've been able to buy ammo for $16-17 a box of 50 over the past couple of months, that's not very expensive in my book.

It's less expensive here than .223.

 

[grampajack]

Yea, I can usually get it from PSA for 16-17 a box. That's really not too horrible considering how uncommon it is. I mean, just look at the price of .380 and .32 ACP!

 

[Zerodefect]

Straight from the horses mouth what the P90 was meant for:


Note the double wall, where the rounds don't make it through too the second wall.

 

[grampajack]

Straight from the horses mouth what the P90 was meant for:


Note the double wall, where the rounds don't make it through too the second wall.

That doesn't mean they intentionally designed it to only penetrate 10'' in bare gel, or that that's a good thing. That's also FN's own advertising, not the parameters they were following for the NATO solicitation. As far as I know, the parameters of the solicitation didn't say anything about limiting penetration in any way.

And nothing changes the fact that the P90 was an abysmal failure for the sole reason that it failed to meet conventional minimum standards for stopping power due to its low penetration. Were it not for that, I have no doubt that it would have been a raging success. It's a wonderful weapon, and everyone who has ever used one loves it, but you just can't get around the fact that it's too underpowered. The MP7, designed for the same solicitation, failed for the same reason. The parameters laid out by NATO were simply not achievable, at least not while meeting basic penetration requirements.

 

[MTMilitiaman]

Wonderful concept and I love FN for bringing it to the civilian market in some form, but not sure the platform has much of a future in the US. SBRing it is much more difficult here and it makes no sense as anything else. The cartridge is neutered in commercial market to the point where some .22 WMR loads come really close to matching them. And then there is the .22 TCM, which offers better performance from more common platforms. I'd still love a 17S and respect FN for giving the US market a try with the PS90, but I don't see it being a raging success here.

 

[wally]

That is so sad that you are only allowed 5 rounds.

I was jealous that you could have what would be a $200 tax NFA short barreled rifle here, until I learned that you are stuck with using only 5 round mags. Designed to hold 50, loading them ain't so bad when you can shoot a whole box in one loading, but needing to load it ten times to shoot a box of ammo sure makes me rather have standard capacity mags and live with the longer 16" barrel.

I'm sure a criminal or terrorist couldn't figure out how to remove the pop rivets and load 50 rounds for their evil

 

[grampajack]

I'm sure a criminal or terrorist couldn't figure out how to remove the pop rivets and load 50 rounds for their evil

But that would be illegal, and we all know that criminals always obey the law!

 

[Dragonfly]

At least riveted mags are legal...it'd be worse if five round factory mags were mandated, which would mean a lot of rifles wouldn't be allowed at all.

 

[muzzleblast...]

Thank you for your excellent review of the PS90.

 

[Danoobie]

What are you using? I got one of the newer ring sights and it's perfect for me. It was way overpriced, but I couldn't be happier with it.

The PS90 I got has the rail, with iron sights in the mount, and a holo sight on the rail. Which gives the whole
package an unnecessarily high profile, IMHO. I DNK if they make this sight system confusing, on purpose,
but I surely wish I knew, before I bought the gun, what I know now.