Kak Xm177 Fh Clone Correct 1/2X28

The Kak Industry XM177 FH Clone Correct 1/2x28 is a retro-spec muzzle device built for shooters who want authentic XM177 moderator aesthetics on modern AR-15 builds. With an integrated grenade ring and extended profile, this 1/2x28 threaded device captures the distinctive look of the Vietnam-era XM-177 line while serving real practical purposes—it can extend a 12.5" barrel to legal rifle length when pin and welded, and it pairs seamlessly with a crush washer hidden inside the grenade ring counter bore so nothing shows once installed.

If you're building a clone-correct rifle (whether a Colt 639, 649, 619, 620, or dedicated XM177/177E1/177E2 platform), this Kak muzzle device gives you the historically accurate silhouette without added complexity or loose parts. The heat-treated phosphate coating handles the elements and use, and the design philosophy keeps the build simple—no extra hardware to manage or track.

This is a straightforward choice for builders and collectors who care about correct specs: whether you're restoring a vintage rifle concept or building a purpose-built clone rifle that looks and functions period-correct, the XM177 FH delivers that aesthetic with genuine utility.

Key Features

• Integrated grenade ring for authentic XM-177 moderator appearance
• Crush washer counter bore hides fastener hardware once installed
• Heat-treated phosphate coating for durability
• 1/2x28 thread pattern for common AR-15 platforms
• Extended profile extends 12.5" barrel to legal rifle length when pin and welded
• Clone-correct design for XM177, 177E1, 177E2, and Colt 639/649/619/620 builds

Specifications

Frequently Asked Questions

Is this muzzle device legal on a short-barrel rifle?

When pin and welded to a 12.5" barrel, this device's extended length brings the overall rifle to legal non-NFA length. However, pin-and-weld legality and barrel length rules vary by jurisdiction—check your local and federal firearms regulations before modifying your barrel.

What thread pitch do I need?

This muzzle device is 1/2x28 threaded, the standard pattern for most AR-15 platforms. Verify your barrel's thread pitch before purchase.

Does this include a crush washer?

The crush washer is not included with the muzzle device. However, the design includes a counter bore in the grenade ring that houses a crush washer, so once installed the fastener remains hidden.

What makes this "clone correct"?

The integrated grenade ring and extended profile replicate the appearance and geometry of the original XM-177 moderator, making it purpose-built for historically accurate builds of Colt 639, 649, 619, 620 and XM177-series rifles.