Geissele Automatics Super Modular Rail MK14 13.50" M-LOK Black Aluminum for AR Platform with Barrel Nut - 05573B

The Geissele Automatics Super Modular Rail MK14 is a 13.50-inch free-float handguard built for AR platform rifles where modularity and shooter ergonomics matter. This slim-profile rail system is purpose-built for operators who run rail covers and vertical grips while maintaining a thumb-over-the-bore support hand position—a setup that demands a handguard that doesn't fight your grip. The MK14 delivers the mounting real estate you need without the bulk, letting you build the accessory configuration your mission demands.

The rail layout is thoughtfully engineered: M-LOK slots run the full length of the handguard at the 3, 6, and 9 o'clock positions, giving you plenty of options for lights, lasers, panels, and bipods. The top features an uninterrupted Picatinny rail running end-to-end—ideal for optics offsets or forward-mounted accessories. Geissele also integrated QD pushbutton sling swivel sockets at the 1 and 11 o'clock positions at the rear, so you can attach a quality sling without needing rail real estate. The free-float barrel nut—proprietary to Geissele and included with the handguard—is 2.25 inches long, providing ample bearing surface for rigid, straight barrel anchoring and improved accuracy consistency.

Built from 6061 T6 machined aluminum and finished in Type III hardcoat anodize, the MK14 is lightweight and durable enough for serious use. The black anodize provides a professional appearance while resisting wear. Installation is straightforward thanks to Geissele's engineered fit, though you'll need to source your own gas block if your build requires one.

Key Features

• Free-float barrel nut system for consistent accuracy and rigid mounting
• M-LOK mounting slots at 3, 6, and 9 o'clock positions for flexible accessory configuration
• Full-length top Picatinny rail for optics offsets and forward-mounted gear
• QD sling swivel sockets pre-installed at 1 and 11 o'clock (rear)
• Slim cross-section compatible with rail covers and vertical grips
• 6061 T6 machined aluminum with Type III hardcoat anodize finish
• Lightweight, modular design for custom builds and reconfiguration

Specifications

Frequently Asked Questions

Is this handguard compatible with my AR-15?

Yes, the MK14 is designed for AR platform rifles. It uses Geissele's proprietary free-float barrel nut system, which is included with the handguard.

What mounting systems does the MK14 use?

The MK14 features M-LOK slots running at the 3, 6, and 9 o'clock positions along the full length of the handguard, plus an uninterrupted Picatinny rail on top. QD sling swivel sockets are pre-installed at the 1 and 11 o'clock positions at the rear.

Do I need to buy a barrel nut separately?

No. The proprietary free-float barrel nut is included with the handguard, and it's engineered specifically for secure, rigid mounting to Geissele specifications.

What's included in the box?

The MK14 comes with the handguard and the proprietary barrel nut. A gas block and barrel nut wrench are not included and should be sourced separately if needed for your build.