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.
- 9″ 300BLK (Carbine Gas System with A2 muzzle device & Brace)
- 10.5″ 300BLK (Carbine Gas System with A2 muzzle device & Brace)
- 16″ 300BLK (Carbine Gas System with A2 muzzle device & B5 Stock)
- 10.5″ 5.56 (Carbine Gas System with A2 muzzle device & Brace)
- 11.5″ 5.56 (Carbine Gas System with A2 muzzle device & Brace)
- 13.7″ 5.56 (Midlength Gas System with P/W Nox & B5 Stock)
- 13.7″ 5.56 (Midlength Gas System with P/W Nox & B5 Stock)
- 14.5″ 5.56 (Midlength Gas System with A2 muzzle device & B5 Stock)
- 16″ 5.56 (Midlength Gas System with A2 muzzle device & B5 Stock)
- 16″ Match 223 Wylde (Midlength Gas System with NOX & B5 Stock)
- 18″ Match 223 Wylde (Midlength Gas System with NOX & B5 Stock)
- 13.9″ Match 6.5 Grendel (Carbine Gas System with NOX & B5 Stock)
- 18″ Match 6.5 Grendel (Carbine Gas System with NOX & B5 Stock)
- 18″ Match 6MM ARC (Midlength Gas System with NOX & B5 Stock)