Faxon Firearms Duty Series AR-15 350 Legend 16in Upper Receiver Gunner Carbine Length 1-16 Twist 1/2x28 w/BCG Supressor Black. Built around our proven 16in Duty Series Gunner Barrel and tuned with a Faxon patented adjustable gas block this upper delivers smooth cycling and consistent functionideal for training defensive use and suppressed setups. Unlike a barreled upper this is a complete upper and ships ready to run with a Faxon Superfinished M16 Bolt Carrier Group (Nitride) and a MIL-SPEC charging handle. Up front a Faxon MuzzLok Plan B-compatible flash hider supports common Plan B mounting systems and makes this upper an excellent suppressor host. Specifications for Faxon Firearms Duty Series AR-15 350 Legend 16in Upper Receiver: Manufacturer: Faxon Firearms Caliber: .350 Legend Overall Length: 25.25 in Barrel Length: 16 in Barrel Profile: Gunner Barrel Twist Rate: 1-16 Firearms Threads Per Inch: 1/2x28 Color: Black Gun Model: AR-15 Fabric/Material: Stainless Steel Handguard Length: 15 in Gun Make: AR Platform Flutes: No Package Contents: Faxon Firearms Duty Series AR-15 350 Legend 16in Upper Receiver What firearm models does the manufacturer say Faxon Firearms Duty Series AR-15 350 Legend 16in Upper Receiver is compatible with? The manufacturer suggests that Faxon Firearms Duty Series AR-15 350 Legend 16in Upper Receiver is compatible with AR-15Faxon Firearms FX-URG-D350L16GA15-C-SR: Duty Series AR-15 350 Legend 16in Upper Receiver Gunner Carbine Length 1-16 Twist 1/2x28 w/BCG Supressor Black