Sons of Liberty Gun Works M4-L89 5.56mm 13.7" Bbl Mid Gas L89 Rail P&W HUXWRX XL Mt Liberty Fighting Bbl & Mil-Spec Upper Receiver U-M4L89-556-137-HUX

The Sons of Liberty Gun Works M4-L89 Barreled Upper is a duty-ready, non-NFA upper assembly optimized for shooters utilizing the Huxwrx Flow-series suppressors. It features a 13.7-inch Liberty Fighting Barrel with a Pin and Welded (P& W) Huxwrx XL Flash Hider, which brings the permanent overall length to the legal 16-inch requirement for standard rifles. The foundation of this build is the L89 Drivelock handguard, featuring a titanium barrel nut and a high-strength locking interface to ensure that rail-mounted lasers and optics maintain a precise zero under thermal stress or hard use. This configuration utilizes a mid-length gas system, providing a balanced and reliable recoil impulse that is particularly effective when shooting suppressed. Sons of Liberty Gun Works M4-L89 5.56mm 13.7" Bbl Mid Gas L89 Rail P& W HUXWRX XL Mt Liberty Fighting Bbl & Mil-Spec Upper Receiver U-M4L89-556-137-HUX