Magpul M-LOK Polymer RAIL (5 SLOTS)

Product Description

The Magpul M-LOK Polymer Rail 5 Slot (MAG590) is a polymer rail section that attaches to M-LOK compatible handguards and forends to create a Picatinny rail surface. It allows you to mount accessories that require Picatinny attachment.

This rail gives you flexibility to position lights, vertical grips, bipods, and other 1913 Picatinny accessories exactly where you need them. The five-slot length provides enough real estate for most common add-ons without adding unnecessary bulk.

Polymer construction keeps weight down compared to aluminum rail sections. The M-LOK system lets you add rails only where you need them rather than surrounding the entire handguard with unused rail surface.

Key Facts

• Model: MAG590
• Brand: Magpul
• Length: 5 slots of Picatinny rail
• Attachment: M-LOK mounting system

How M-LOK Rail Sections Work

M-LOK is a direct-attach system that uses slots machined into the handguard. Rail sections like the MAG590 use T-nuts that slide into those slots and are tightened from above. This creates a secure mount without surrounding the entire handguard in rail.

The advantage is weight savings and ergonomics. You install rail sections only where you plan to mount accessories, leaving the rest of the handguard smooth. When you remove an accessory, you can remove the rail section too.

What This Rail Section Fits

The Magpul M-LOK Polymer Rail 5 Slot attaches to any handguard or forend with M-LOK slots. It does not fit KeyMod slots or traditional screw-and-nut accessory mounting systems.

Verify that your handguard has M-LOK slots before ordering. Most modern AR-15 handguards and many shotgun forends now use M-LOK. If you are unsure about compatibility with your specific setup, send us a message and we will walk you through it.

Choosing Between Polymer and Aluminum Rail Sections

Polymer rail sections like the MAG590 weigh less than aluminum versions and cost less. They handle the mounting loads of lights, lasers, and grips without issue.

Aluminum rail sections are typically chosen when the accessory generates significant heat, such as a laser that runs continuously, or when the rail will see hard impacts. For most shooters mounting common accessories, polymer performs well and keeps the rifle lighter.

Ordering from Western Sport

Order online and it ships straight to your door. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.

Frequently Asked Questions

Q: Does the Magpul M-LOK Polymer Rail 5 Slot fit KeyMod handguards?

A: No, the MAG590 is designed specifically for M-LOK slots and will not attach to KeyMod mounting systems. M-LOK and KeyMod use different slot shapes and hardware, so rail sections are not interchangeable between the two systems.

Q: How many Picatinny slots does this rail section provide?

A: The Magpul MAG590 provides five slots of Picatinny rail space. That is enough length for most lights, laser modules, hand stops, or short vertical grips.

Q: Can I mount a bipod on the Magpul M-LOK Polymer Rail 5 Slot?

A: Yes, as long as the bipod has a Picatinny clamp or mount and fits within the five-slot length. Most Harris-style bipods and similar models will attach securely to this rail section.

Q: Will this rail hold up under the weight of a weapon light?

A: Yes, polymer M-LOK rail sections handle the mounting load and recoil forces from weapon lights, laser aiming modules, and similar accessories without issue. The M-LOK attachment system and polymer construction are both designed for this use.

Q: How do I install the Magpul MAG590 on my handguard?

A: The rail section uses T-nuts that slide into the M-LOK slots from the side or end of the handguard. Once positioned, you tighten the screws from the top of the rail using a hex key. Magpul publishes torque specifications for their M-LOK hardware; send us a message if you need installation assistance.

Q: Does Magpul offer a warranty on the M-LOK Polymer Rail?

A: Magpul stands behind their products, but for specific warranty terms and coverage details on the MAG590, send us a message and we will provide current information or connect you with Magpul directly.

Additional information