I've wanted a P90 since I was a teenager. Not because of Stargate SG-1, which is where most Western fans first saw it as the team's standard-issue weapon, but because of Gunslinger Girl. That anime put the odd, futuristic bullpup in front of me years before I knew anything about the real gun behind it.
Then my neighbor's dad bought a Tokyo Marui P90. Holding it as a kid sealed the deal, and I promised myself I'd own one someday.
Someday turned out to be March of this year. I didn't end up with the Tokyo Marui. I picked up the King Arms FN P90 AEG (M3) from Neknek's Airsoft Shop for PHP 13,000, and I don't regret it. The Dark Earth lower receiver feels sturdier in hand than the TM I grew up admiring.
Six months later, this King Arms P90 AEG review is less a first-impressions piece and more a service record. I chrono'd it stock and played it stock. Then I pushed it too hard, broke things, rebuilt the gearbox with better parts and 3D printed two new bodies for it along the way. If you're eyeing your first P90 or deciding whether this is a good base for a build, this one's for you.
The Gun Everyone Recognizes and Almost Nobody Issues
FN Herstal designed the real P90 as a personal defense weapon for troops who needed something compact without giving up too much range. It never became a mainstream service rifle. Its top-mounted magazine and bullpup shape made it instantly recognizable anyway, and that's exactly why airsofters want one. Nothing else on the field looks like it.
King Arms has made a P90 AEG for years. The company doesn't advertise it as Tokyo Marui compatible, but under the shell it follows the TM gearbox pattern. That matters more than anything on the outside. TM's pattern is the default for the airsoft aftermarket, so a gun that follows it can take the same pistons, motors and gears that fit thousands of other AEGs. A proprietary gearbox would lock you into one brand's parts catalog. This one doesn't.
King Arms P90 AEG at a Glance
Model: King Arms FN P90 AEG (M3)
Price paid: PHP 13,000 at Neknek's Airsoft Shop
Stock velocity: 380 FPS with 0.20g BBs (shop chrono on day of purchase)
Gearbox: Tokyo Marui-pattern P90 gearbox with a quick-access spring
Finish: Dark Earth lower receiver with a black upper
Tested: Six months of field use at The Nest: Alpadi, stock and upgraded
Out of the Box: 380 FPS and an Easy Spring Swap
When we chrono'd it at the shop on the day I bought it, it read 380 FPS with 0.20g BBs. That's hot for a stock AEG and more than enough for most outdoor games.
My home field, The Nest: Alpadi, caps standard rifles at 450 FPS. That left me 70 FPS of legal headroom, and that headroom is the whole reason I went chasing more power later. Your field's limit is probably different and CQB venues usually sit much lower, so chrono yours before assuming stock means field-legal.
The P90 also makes spring changes quick. Getting to the spring takes less work than on a lot of AEGs I've handled. It's a handy feature. It's also the feature that got me into trouble.
Six Months, One Broken Piston and a Cracked Gearbox
I wanted more FPS, so I dropped in a Guarder SP130 spring and changed nothing else. The stock piston body broke almost right away. That one's on me. A spring that much stronger than stock needs a piston built to take the extra load, and I skipped that step because the swap itself was so easy.
So I rebuilt it. In went a Slong reinforced piston body with a matching Slong piston head, an Element Hi-Torque motor, SHS 18:1 gears, a Slong reinforced anti-reversal latch and a metal nozzle with double O-rings. I also replaced the barrel with a Unicorn 6.03mm 267mm tightbore, used the hop bucking and nub that came with it, and installed a CNC aluminum ProWin hop chamber made for the P90.
The hop chamber came with a catch. Aluminum is less forgiving than the stock plastic, and my magazine lips started chipping. I used to slap mags in. Now I seat them gently. It's a small habit change, but you'll have to make it too if you go this route.
Next came a Perun MOSFET for the P90, which replaces the entire trigger assembly. The sharper trigger response and contact protection make it worth it, but it wasn't a clean drop-in. I had to remove a couple of screws near the main trigger to make room for it. They're cosmetic on this gun and don't hold anything together, so nothing was lost. From what I've seen online, the same MOSFET drops straight into a Tokyo Marui P90 with no extra work. It's a small reminder that a clone isn't identical to the gun it copies.
Even after all that, the SP130 kept winning. It burned out the motor and left hairline cracks in the gearbox shell. I swapped in an SHS Hi-Torque motor, ordered a replacement gearbox directly from King Arms and dropped down to a Guarder SP120. I'm done chasing FPS. Looking back, it was a rookie move.
No single part let me down here. The mistake was pushing the spring past what everything else in the gearbox could handle.
The gearbox wasn't the only part I had to reorder. I also broke the muzzle threading on the original upper receiver and bought a replacement directly from King Arms. The one that arrived carries limited edition markings, a tribute to the GIGN and its 1994 rescue of the passengers on hijacked Air France Flight 8969. I didn't ask for it, but it turned a repair into a small upgrade.
Two New Bodies Off the 3D Printer
The P90 also plays nicely with my other hobby, 3D printing. So much of its look comes from the upper and lower shells that you can change its entire identity without touching the gearbox.
I printed a shorter upper receiver to turn it into a compact SMG.
Later I went the other way and printed a longer upper that turns it into a DMR-style carbine.
Neither build changes performance. They're cosmetic shells over the same internals, and that's the appeal. If you own a printer, few AEGs give you this much room to play.
King Arms P90 AEG Price in the Philippines: What PHP 13,000 Buys You
At PHP 13,000, the King Arms P90 sits in the middle of the local AEG market. It costs more than true entry-level replicas and less than premium builds with proprietary electronics or full-metal everything. What you're paying for is a P90 shell that few brands bother making, with TM-pattern internals underneath.
That second part is the real value, and King Arms never says it out loud. You find it when you open the gearbox and realize nearly every upgrade part at your local shop will fit. Of everything I bought for my rebuild, only the Perun MOSFET needed extra work to install.
A Quiet Clone, Not a Marketed One
Here's where buyers should adjust their expectations. "TM clone" describes the shape of the gearbox. It says nothing about the quality of the parts inside it. Plenty of AEGs in this price range ship a correctly shaped gearbox full of parts rated for stock use and little else, and the King Arms P90 is one of them.
To be fair, King Arms never promises otherwise. There's no compatibility badge on the box and no upgrade-ready claim on the product page, so the company can't be blamed for a standard it never advertised. What it does own is what ships inside. The stock piston and gearbox shell are fine at 380 FPS. They aren't built for a big step up, and anyone planning one should budget for reinforced parts from day one.
King Arms P90 AEG Pros and Cons
Pro: TM-pattern internals mean affordable, widely available upgrade parts with no brand lock-in.
Pro: The P90 shape is rare at this price and still turns heads on the field.
Pro: The Dark Earth lower receiver feels sturdier than the Tokyo Marui version's.
Pro: 380 FPS with 0.20g BBs straight out of the box.
Pro: Quick spring changes make it easy to tune.
Pro: King Arms sells replacement parts directly, from gearbox shells to complete upper receivers.
Pro: The shell design makes 3D-printed conversions easy without touching the gearbox.
Con: The stock piston body can't handle a big spring upgrade. Mine broke on the first try.
Con: The gearbox shell can crack under a much stronger spring if the rest of the build isn't reinforced to match.
Con: Installing a Perun MOSFET means removing a couple of cosmetic screws, unlike the reported drop-in fit on the Tokyo Marui P90.
Con: An aluminum hop chamber upgrade wears down magazine lips faster than the stock plastic one.
Verdict: Is the King Arms P90 AEG Worth It?
If you want a P90, buy this one. Then do the opposite of what I did.
Keep it stock until something breaks or until you notice a specific weakness. Then fix that weakness and nothing else. Upgrading everything at once just because the parts are cheap and available is how I ended up with a cracked gearbox.
Want more range, better accuracy or the option to shoot heavier BBs? Start with the hop bucking. Want more FPS and accuracy from the barrel? A tightbore helps, but only if the bore is smooth as well as tight. Unicorn earns its reputation there. Cheaper tightbores, even ones rated at 6.01mm, can hurt accuracy if the inner surface is rough, so don't shop by the number alone. Losing efficiency or getting inconsistent shots? An aluminum nozzle and hop chamber will improve air seal. Just be gentle with your mags afterward.
What you shouldn't do is jump straight to a stronger spring. It stresses every part behind it at once, and in my case it took out a piston, a motor and a gearbox shell. Would I buy the King Arms P90 again? Without hesitation. Would I upgrade it the same way? Not a chance.