Sons of Liberty Gun Works M4-L89 Upper Receiver Group, Upper Receiver, 5.56 NATO, P/w Pln B

Product Description

The Sons of Liberty M4-L89 5.56 upper receiver is a complete, ready-to-mount assembly designed for serious AR-15 builders. This precision-engineered upper features a 14.5″ 5.56 NATO barrel paired with a pinned and welded Plan B flash hider. As a result, it achieves a legal 16″ overall length without a separate muzzle device.

Furthermore, the M4-L89 includes a 13.75″ free-floating rail system. This rail provides excellent real estate for mounting optics, lights, and tactical accessories. The matte black finish resists corrosion and delivers a professional appearance. Quality and reliability are built into every component.

Complete Upper, Ready to Install

The M4-L89 URG arrives fully assembled and ready for installation on any mil-spec AR-15 lower receiver. However, you will need to supply a bolt carrier group and charging handle separately. These components are not included, so plan accordingly when ordering your build parts.

Additionally, the Sons of Liberty M4-L89 excels at multi-platform versatility. Builders can customize optics and accessories to match their exact mission. The precision barrel ensures reliable cycling and accurate shot placement for training or tactical use.

Built for Builders, Competitors, and Professionals

This upper receiver suits rifle builders, competitive shooters, and tactical professionals alike. The pinned and welded flash hider configuration meets legal requirements in most jurisdictions. Moreover, the free-floating rail system supports both close-quarters and precision long-range applications.

Finally, you’re investing in American-made quality from a manufacturer trusted by professionals nationwide. The Sons of Liberty M4-L89 will serve you reliably for years of shooting, training, and competition.

Ordering from Western Sport

Order online and it ships straight to your door. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.

Frequently Asked Questions

Q: Will the Sons of Liberty M4-L89 upper receiver fit my AR-15 lower receiver?

A: Yes, the M4-L89 URG is designed to fit any mil-spec AR-15 lower receiver. The upper assembly uses standard AR-15 dimensions and mounting interfaces. Installation requires only proper tools and basic assembly knowledge.

Q: What additional parts do I need to complete my M4-L89 build?

A: The M4-L89 upper receiver does not include a bolt carrier group or charging handle. You will need to purchase these components separately to complete your rifle. All other upper receiver functions arrive complete and ready for use.

Q: Can I legally transfer this upper receiver in Texas?

A: Yes, as a licensed FFL/SOT dealer in Texas, Western Sport can help facilitate your transfer and answer state-specific legal questions. The pinned and welded configuration meets federal and most state firearm length requirements. Send us a message to confirm your specific location and any local regulations.

Q: Is the Sons of Liberty M4-L89 suitable for precision shooting competitions?

A: Absolutely, the M4-L89 performs excellently in competitive shooting environments. The free-floating rail and quality barrel support accurate long-range shooting and training applications. Many competitive shooters favor Sons of Liberty Gun Works for reliability and precision.

Additional information