Battle Arms Development 13" Workhorse MLOK Free-Float Rail - Black

The Battle Arms Development 13" Workhorse MLOK free-float rail brings lightweight modularity to your AR platform without unnecessary bulk. Built for shooters who want to mount optics, lights, and accessories exactly where they need them—no more, no less—this handguard gives you M-LOK slots at the 3, 6, and 9 o'clock positions so you can configure your rifle to your specs. The top remains a full 1913 MIL-SPEC Picatinny rail (notch-cut to save weight and match modern upper receivers), so your scope or red dot mounts securely where it belongs.

At 13 inches, this rail suits mid-length to longer-barreled builds where you want real estate for mounting without overhanging your muzzle. The skeletonized design—aluminum removed where it serves no structural purpose—keeps your rifle nimble without compromising strength. Free-floating design isolates the barrel from the handguard, which can help with accuracy consistency by removing variables that can shift zero.

Built from 6061 T6 aluminum and finished in Type 3 black hardcoat anodize, the Workhorse is tough enough for hard use and professional enough for a duty rifle. Installation is straightforward: the barrel nut torques to 30–45 ft-lbs, and M-LOK screws are set at 10–15 in-lbs. If you're building a lightweight carbine or upgrading a rifle that needs a cleaner, more capable handguard, this rail delivers the functionality serious shooters expect.

Key Features

• M-LOK compatible mounting at 3, 6, and 9 o'clock positions for lights, grips, and accessories
• 1913 MIL-SPEC Picatinny rail at 12 o'clock for optics and top-mounted gear
• Free-float design isolates barrel for consistent accuracy
• Skeletonized construction reduces weight where stiffness isn't critical
• 6061 T6 aluminum with Type 3 black hardcoat anodize for durability
• Available in multiple lengths (4", 6.7", 9.5", 13", and 15") to fit your build

Specifications

Frequently Asked Questions

What AR platforms is the 13" Workhorse rail compatible with?

The Workhorse is designed for MIL-SPEC AR carbines and modern uppers. The internal diameter is 1.36", and the free-float design mounts via a standard barrel nut. Verify that your upper receiver and barrel nut are MIL-SPEC compatible before installation.

Can I mount an optic on this handguard?

Yes. The Workhorse features a full 1913 MIL-SPEC Picatinny rail along the top (12 o'clock), so any standard Picatinny optic mount or scope ring will work. The notch-cut design fits modern uppers while saving weight.

What accessories can I attach with M-LOK?

The M-LOK slots at the 3, 6, and 9 o'clock positions accept standard M-LOK-compatible gear—light mounts, sling attachments, vertical or angled grips, panels, and other modular accessories. You configure it to match your mission.

Is this rail a free-float design, and what does that mean?

Yes, it's a free-float rail, meaning the barrel is isolated from the handguard. This removes potential friction or pressure on the barrel, which can improve shot-to-shot consistency by reducing variables that might shift your zero.