The SOLGW M4-89 is Sons of Liberty Gun Works' flagship 5.56mm carbine, built to exceed mil-spec with enhanced bolt carrier group, SOLGW-enhanced lower parts kit, and proprietary muzzle device. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2012, USA Weight: 64 oz Overall length: 33" Status: Active Intended use: Tactical