This 5.56 chambered 11.5 inch Government Profile Modern Series Barrel from Ballistic Advantage is machined from 4150 Chrome Moly Vanadium steel with a QPQ Corrosion Resistant Finish and QPQ coated M4 feed ramp extension. All Ballistic Advantage barrels are guaranteed to give sub Minute of Angle (MOA) accuracy with match-grade ammunition. They define sub-MOA as a group size of 1 inch or under at 100 yards with a 3 shot magazine fed group, or 5 shot single-loaded group factory ammo. Made from 4150 Chrome Moly Vanadium with a QPQ Corrosion Resistant finish Chambered in 5.56 NATO M4 Feed Ramp Extension 11.5? long 1/2x28 thread 1-7" twist rate 20.5oz Government profile Carbine length gas system SKU: BABL556023M