CMMG 300BLK 12.5" Pistol Nitride 4140 Barrel .750 Gas Diameter
Perfect for building your custom AR15 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly headspaced.
NOTE: CMMG now uses +0.002" Head Space gauges which is the new industry standard. Customers trying to use standard gauges will find they do not check correctly.
12.5"Medium Taper Profile4140 Chrome MolySalt Bath Nitride Finish inside and out1:7 Twist300 AAC Blackout ChamberThreaded 5/8-24Pistol length gas port.750" Gas Journal