Sons of Liberty Gun Works M4-L89 5.56 NATO Barreled Upper Receiver - 13.9" - SilencerCo ASR

The Sons of Liberty Gun Works M4-L89 Upper Receiver is built for users who demand durability, balance, and maximum mounting space. It features a 13.9" V2 barrel paired with the 13.75" L89 M-LOK handguard and comes equipped with a SilencerCo ASR muzzle device. This setup provides a solid foundation for both suppressed and unsuppressed use.

The 13.75" L89 handguard includes a titanium barrel nut, seven-sides of M-LOK slots for versatile accessory placement, two integrated QD sling sockets, and open cooling slots beneath the top rail to promote airflow. The compact profile of the handguard gives users as much usable space as possible for attachments without adding unnecessary weight.

Note: Bolt carrier group and charging handle are not included.

Features:

• 13.9" 5.56 NATO V2 barrel
• 13.75" L89 7-sided M-LOK handguard
• Integrated steel limited-rotation QD sling sockets
• Open cooling slots under 12 o’clock rail for heat dissipation
• SilencerCo ASR muzzle device installed
• Forged upper receiver
• Tuned gas system for use with or without suppressors
• Designed for use with low-profile gas blocks (not compatible with FSBs)
• BCG and charging handle not included

The V2 barrel features increased chamber support and a redesigned profile that moves material rearward to better balance the rifle when outfitted with lights, lasers, or suppressors. This shift in weight distribution also increases barrel stiffness to reduce point-of-impact shift. The gas system is tuned to function reliably with suppressed and unsuppressed setups, and the shortened gas journal is optimized for low-profile gas blocks only.