Faxon Firearms Duty Barrel AR Platform AR-10 .308 WIN 13.9in Big Gunner Mid Length 1-10 Twist 5/8-24 Thread Black. 308 continue our fantastic barrel-making with a bit more punch. We've updated our previous Medium-Taper profile taking into account customer feedback optimizing the barrel to meet the Gunner brand's high standards. The .308 Big Gunner profile barrels are the big-brother to our famous 5.56 Gunner barrels. The Big Gunners feature a medium-taper behind the gas block. Specifications for Faxon Firearms Duty .308 WIN Barrel: Manufacturer: Faxon Firearms Color: Black Finish: Nitride Fabric/Material: 4150 CMV Steel Caliber: .308 Winchester Barrel Length: 13.9 in Barrel Profile: Gunner Gas System Length: Mid Length Gas Block Journal Size-Diameter: .750 in Threads per Inch: 5/8x24 Barrel Twist Rate: 1-10 Gun Make: AR Platform Gun Model: AR-10 Weight: 2.13 lb Package Contents: Faxon Firearms Duty .308 WIN Barrel What firearm models does the manufacturer say Faxon Firearms Duty .308 WIN Barrel is compatible with? The manufacturer suggests that Faxon Firearms Duty .308 WIN Barrel is compatible with AR-10Faxon Firearms 10A810M139NGQ: Duty Barrel AR Platform AR-10 .308 WIN 13.9in Big Gunner Mid Length 1-10 Twist 5/8-24 Thread Black