CMMG 55DC70A Barrel Sub-Assembly 5.56x45mm NATO 16.10" Black Nitride Finish 4140 Chromoly Steel Material Midlength with Medium Taper Profile for AR-15
https://www.tandktactical.com/shop/815835016153-cmmg-55dc70a-barrel-sub-assembly-5-56x45mm-nato-16-10-black-nitride-finish-4140-chromoly-steel-material-midlength-with-medium-taper-profile-for-ar-15-536
https://www.tandktactical.com/web/image/product.template/536/image_1920?unique=a454736
CMMG's Barrel Sub-Assembly is ideal for building your custom AR-15 upper group. It comes with properly installed M4 barrel extension.
