Sons of Liberty Gun Works M4 L89 AR-15 Pinned and Welded Upper Receiver Assembly 5.56x45mm NATO 14.5" Barrel with Plan B Mount

These Sons of Liberty Gun Works L89 Upper Receiver Groups are built using a forged upper. These uppers have V2 Button rifled barrels, V2 4140 gas block, and offered in a variety of length and muzzle device options. L89 rails have 7-sided MLOK, and integral QD's for maximum available MLOK utilization. FeaturesButton Rifled BarrelM-LOK Rail