Daniel Defense 10.3" 5.56 Government CHF Barrel

Daniel Defense's standalone 10.3" Government Carbine barrel is the factory barrel spec builders use when recreating the MK18 upper piece by piece. The CMV (Chrome Moly Vanadium) bore is cold hammer forged, chrome lined for service life, and finished with mil-spec heavy phosphate on the exterior to resist corrosion. The M4 feed ramps are cut directly into the barrel extension to keep feeding reliable through common 55 to 77 grain 5.56 NATO ammunition.

The 1:7 twist stabilizes the common 5.56 NATO projectile range. The .750 inch gas journal accepts a low profile gas block, and Daniel Defense ships the barrel in two SKUs: 07-077-16176-018 is the bare barrel for builders pinning their own gas block, and 07-077-06128 includes the matched 4140 steel pinned low profile gas block for builders who want a turnkey solution. Both versions use a carbine length gas system that matches the 10.3" barrel and 9.55" RIS II handguard layout.

Practical notes for clone builders: the threaded muzzle is 1/2x28 for a SureFire SOCOM 3-prong or A2 birdcage. If you are building toward a clone-correct MK18 Mod 1, this is the Daniel Defense 10.3 inch barrel path without buying a complete upper. If you are running an MK18-style 10.3" build with a different rail, you still get the same barrel quality the complete upper is built around.