CMC Triggers 10.5in AR15 Barrel 5.56 Nato 1/7 41V50 CRMOV Black. 56 NATO ammo. With a Carbine length gas system" M4 feed ramps for reliability" a 1:7" twist rate" 1/2"x28 thread pattern to fit standard AR-15 muzzle devices" 11 degree match crown for increased accuracy and a bottom dimple is added for easy install and alignment of gas blocks. Specifications for CMC Triggers 10.5in AR15 Barrel 5.56 Nato 1/7 41V50 CRMOV: Manufacturer: CMC Triggers Color: Black Finish: Nitride Black Caliber: 5.56x45mm NATO Barrel Length: 10.5 in Barrel Twist Rate: 1-7 Gun Make: AR Platform Gun Model: AR-15 Case Finish: Nitride Handle Color: Black Blade Finish: Nitride Threads per Inch: 1/2x28 Features of CMC Triggers AR-15 Barrel 556 NATO 17 Twist Carbine Length Gas System 10.5 Long Government Profile Threaded 1/2x28 Nitride Finish Black: Carbine length gas system Package Contents: CMC Triggers 10.5in AR15 Barrel 5.56 Nato 1/7 41V50 CRMOV What firearm models does the manufacturer say CMC Triggers 10.5in AR15 Barrel 5.56 Nato 1/7 41V50 CRMOV is compatible with? The manufacturer suggests that CMC Triggers 10.5in AR15 Barrel 5.56 Nato 1/7 41V50 CRMOV is compatible with AR-15CMC Triggers CMC-BBL-556-002: 10.5in AR15 Barrel 5.56 Nato 1/7 41V50 CRMOV Black