CMMG

Barrel Sub-Assm, 12.5" MR 4140CM SBN, 300 BLK

Perfect for building your custom AR15 upper group. Comes with a properly installed M4 barrel extension. All barrel sub-assemblies are properly headspaced.

**All NFA rules apply** See linked CMMG Resource article for more information.

All CMMG products come with our Lifetime Quality Guarantee.