Perfect for building your custom AR15 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly head spaced.
Features :
Features :
- 1:7 Twist 4140 Chrome Moly
- 1/2X28 thread pitch
- Heavy taper profile
- "Midlength gas port .936" gas block Journal" 5.56 Nato chamber"