BudsGunShop.com - What about ...?

Caliber
223 Remington/5.56 NATO
Barrel Length
10.3" see *******Daniel Defense manufactures the highest quality complete AR15 upper receivers on the market today. The M4 URG, MK18 comes complete with a bolt carrier group, charging handle, 10.3 inch Cold Hammer Forged Barrel, RIS II MK18 Rail System that is finished in Flat Dark Earth, and a Daniel Defense low profile gas block.
Type
Complete Gas Impingement
Series
Upper FDE
Sights
None, Optic Ready
******Caliber
223 Remington/5.56 NATO
Barrel Length
10.3"
Barrel Material
Chrome Moly Steel
Barrel Description
Cold Hammer Forged
Receiver Description
7075-T6 Aluminum

John, this upper has a 10.3" Chrome Moly Vanadium Steel Cold Hammer Forged Barrel with Government Profile, Mil-Spec Heavy Phosphate Coating & 1:7" twist rate. It is Chambered in 5.56 NATO.