Sons of Liberty Gun Works M4-89 Upper 556 13.7″ Pinned NOX flash hider (16″ OAL)

Overview
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 M4-89. 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)
Twist Rates & Thread Pitches will match caliber. Match-grade firearms will have 416 Stainless Steel barrels.