At Sons of Liberty Gun Works, we believe in Quality Mil-Spec or better parts. We believe there is no substitute for quality and that your gun should be built right the first time, ready for hard use right out of the box. We believe a quality Bolt Carrier Group and a quality, accurate, and long-lasting barrel are the heart of a Combat Grade weapon. We believe in properly tuned weapons using the correct gas system length and quality buffer system components such as the Vltor A5 system and Sprinco Tactical Buffer Springs. We believe in our products and we back them up with a Lifetime Warranty. Our weapons are meant to be used hard and go in harm’s way, they won’t let you down.

All rifles are test fired twice in the shop to ensure proper function.

The M4-89 is one of the premier fighting rifles we offer. It houses a combat grade barrel, A5 buffer system, Liberty Fighting Trigger, and B5 furniture. At Sons of Liberty Gun Works, we always tell our customers that it’s not what a rifle company tells you, it’s what they don’t tell you. Below you will find the complete specifications of the M4-789. We have built our guns to run through years of hard use, and we have nothing to hide.

• Barrel: Sons of Liberty Gun Works 4150CoMOV 1:7 MPI HPT Barrel
• Barrel Steel: 4150 CrMoV (Chrome Moly Vanadium per MIL-B-11595E)
• Twist Rate: 1/7 Twist Six Groove
• Thread Pitch: 1/2-28 Threaded Muzzle
• Gas Block: .750″ Gas Block Journal with appropriately sized gas port
• Barrel Finish: QPQ Corrosion Resistant Finish
• Barrel Extension: QPQ coated M4 Feed Ramp Extension
• High Pressure (proof) Tested (HPT)
• Magnetic Particle Inspected (MPI)