Perfect for building your custom AR15 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly headspaced.
- 16.1?
- Medium Taper Profile
- 4140 Chrome Moly
- Salt Bath Nitride Finish inside and out
- 1:7 Twist
- 5.56�45 NATO Chamber
- Threaded 1/2-28
- Midlength gas port
- .750? Gas Journal
