Perfect for building your custom AR-15 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly headspaced.

Features and Specifications:
Manufacturer Number: 55D9C0A
14.5"
M4 Profile
4150 Chrome Moly Vanadium
Chrome Lined
Maganese Phosphate Coated
1:7 Twist
5.56×45 NATO Chamber
Threaded 1/2-28
Carbine length gas port
.750" Gas Journal

Installing this product will subject it to NFA laws and doing so without a license is a felony possession of a Class III firearm. Check your local laws.