How to Sling an FN P90 or PS90: The Complete Setup Guide
Slinging a P90 is one of those problems that seems like it should be simple and isn’t. The bullpup layout that makes the P90 so compact is the same thing that makes a normal rifle sling useless on it. This guide covers the whole thing: why it’s hard, what actually works, how to set it up single-point, how to convert it to two-point, and the questions P90 and PS90 owners ask most.
Short version: a standard rifle sling doesn’t work well on a P90 or PS90. A single-point harness built for the platform is the clean answer — and by adding one front rail attachment, that same harness converts to a full two-point. Here’s how.
Why is it so hard to put a sling on a P90?
Slinging a P90 is hard because it’s a bullpup — the action sits behind the trigger, so the gun has no conventional buttstock and no standard sling points where you’d expect them. A normal two-point rifle sling runs from the front of the handguard to the rear of a buttstock. The P90 has neither, so a standard sling has nothing correct to attach to.
Most people hit this the same way: they try to adapt a sling built for an AR or a hunting rifle, rig it to the wrong points, and end up with a setup that rides awkwardly, torques the gun, or slips off. The workarounds — zip ties, improvised loops, 550 cord through the factory eyelets — all add bulk and failure points, and cord through the eyelets can actually stop you from shedding the weapon fast in an emergency. The P90 needs a sling designed around its shape, not one forced onto it.
P90 vs PS90 — does the sling difference matter?
The P90 and PS90 share the same body and layout, so a sling built for one fits the other. The main difference is the barrel: the FN P90 is the original short-barrel version, while the FN PS90 is the civilian model with a longer 16-inch barrel to meet U.S. legal requirements. The receiver, grip, and stock geometry — the parts a sling attaches to — are identical.
So for slinging purposes, P90 and PS90 are interchangeable. If you own a PS90 (the common civilian version), a harness described for the “P90” fits your gun exactly the same way.
Single-point vs two-point on a P90 — which should you run?
A single-point setup is the natural fit for a P90, and it comes down to the gun’s size and balance. The P90 is short and centrally balanced, so a single-point harness lets it hang cleanly at your front, swing up fast, and transition between shoulders without fighting the sling. That suits the bullpup’s quick-handling nature.
A two-point sling shines when you want to distribute weight across your body and carry hands-free for long stretches — hiking, field use, long days. The good news for P90 owners is that you don’t have to pick one and live with it. The same harness should run both or at least, give you the ability to do so with only minor adjustments or additional attachments. Start single-point, and when you want two-point, you add one part up front. The next two sections walk through each.
How to mount a P90 sling (single-point, step by step)
Mounting a single-point harness on a P90 is a threading job, not a bolt-on. Here’s the process:
- Open the harness and find the front. The harness wraps the receiver area and routes the strap so the single-point connection sits where the gun balances.
- Thread the fabric through the stock area following the harness routing. This is the step shown in the video above — the fabric passes through the gun’s structure to anchor the sling without adapters.
- Set your dominant-hand orientation before you finish threading (see the lefty section below).
- Secure the hook and loop and pull it snug.
- Connect your single-point sling and check the hang. Let the gun hang, confirm it sits muzzle-down at a natural angle without torquing, then adjust length so it indexes to your shoulder fast without excess slack.
No tools, no drilling, no permanent modification — the harness uses the gun’s existing geometry.
How to run your P90 as a two-point
Here’s what most P90 guides miss: the single-point harness converts to a full two-point, and all it takes is a front attachment point. The P90 and PS90 don’t have a native front sling point — but they do have a front Picatinny rail, and that’s the key.
Add a Magpul RSA (a Picatinny rail sling attachment) to the front rail, and you’ve created the forward sling point the platform is missing. Then it’s simple: your convertible sling’s hook clips into the RSA up front, the harness anchors the rear, and you’re running a true two-point. Want single-point again? Unclip the front. That’s the whole conversion.
Where you mount the RSA on the front rail is your call — position it around your optic and open rail space for whatever’s most comfortable. Running a red dot? Set the RSA clear of the sight. This is the same way an RSA adds a front sling point to any rifle with a Picatinny rail, so the skill and the part carry over to the rest of your guns.
If you run a convertible sling like the Bondo — which switches between two-point and single-point in seconds on its own — the P90 becomes a fully convertible platform: harness + RSA + convertible sling, and you flip between configurations on the fly.
Setting up a P90 sling for a left-handed shooter
A good P90 harness is ambidextrous, but a left-handed shooter should mirror the buckle placement to the opposite side. The harness works for both hands, but the direction you thread the fabric and where the buckle sits will differ.
A right-handed shooter runs the default buckle placement. A left-handed shooter wants it mirrored — the opposite side — which makes threading the fabric through the stock easier and lines the sling up for a left-side carry. If you’re a lefty, set the dominant-hand option to left before you thread it, and the whole setup mirrors cleanly.
Does a P90 sling fit airsoft P90 replicas?
Yes — a harness built for the real FN P90/PS90 fits most airsoft P90 replicas. Airsoft makers build their P90 replicas to closely match the real gun’s external dimensions, so a harness that threads through the real P90’s structure fits the replicas the same way. It’s a popular upgrade for airsoft players stuck with flimsy included straps — same clean single-point (or two-point) setup on a field gun.
What to look for in a P90 sling
A P90 sling should be built from heavy-duty 1-inch nylon webbing, sewn for the load, with hardware that keeps bulk down on a gun prized for being compact. The one we build at Tactical Gear Lines is made in the USA from 1-inch nylon, hand-sewn in our Boise, Idaho shop, ambidextrous, fits airsoft replicas, and is backed by a lifetime warranty. It ships single-point and converts to two-point with an RSA — you can even order it bundled with the RSA so it’s two-point ready out of the box.
Checks every box on that list. Our P90 Sling Harness is 1-inch USA-made nylon, hand-sewn in Idaho, ambidextrous, and lifetime-warrantied — single-point out of the box, two-point ready with a Magpul RSA. Grab the Harness + Sling + RSA kit and you’re two-point ready on day one.
Frequently asked questions:
Can you put a sling on a P90?
Yes, but not with a standard rifle sling. The P90’s bullpup layout has no conventional sling points, so it needs a single-point harness built to thread through the gun’s structure. It mounts with no tools and converts to a two-point by adding a front rail attachment.
What sling fits an FN PS90?
A sling built for the FN P90 fits the PS90 — same body, same stock geometry, only the barrel length differs. A single-point P90 harness is the standard answer, and it runs as a two-point by adding a Magpul RSA on the front rail.
Is a single-point or two-point sling better for a P90?
Single-point is the natural fit because the P90 is short and centrally balanced. But you don’t have to choose — with a harness at the rear and a front rail attachment, the same setup runs two-point and converts back anytime.
Can you run a P90 as a two-point sling?
Yes. Add a Magpul RSA to the front Picatinny rail for a front point, run the harness at the rear, and clip a convertible sling between them. Full two-point, converts back to single-point by unclipping the front.
Does a P90 sling fit airsoft replicas?
Yes — most airsoft P90 replicas match the real gun’s dimensions, so a harness for the FN P90/PS90 fits them too.
How do you set it up for a lefty?
Mirror the buckle placement to the opposite side and set the dominant-hand option to left before threading, so the sling lines up for a left-side carry.
What is a P90 sling harness made of?
Heavy-duty 1-inch nylon, sewn for the load. Ours is made in the USA, hand-sewn in Boise, Idaho, and backed by a lifetime warranty.
Ready to sling your P90 the right way? The P90 Sling Harness is built specifically for the FN P90 and PS90 — single-point out of the box, two-point ready with a Magpul RSA, ambidextrous, made in the USA, and it fits most airsoft P90 replicas too. Order it on its own or as a Harness + Sling + RSA kit, and reach out if you want a custom fit.