Faxon Firearms Match Series AR-15 6mm ARC 16in Upper Receiver Gunner Mid Length 1-7.5 Twist 5/8x24 w/BCG Black. 56 Complete Upper is a duty-grade ready-to-run upper receiver group designed for reliability balance and consistent performance. Built around Faxons proven 16in Duty Series Gunner Barrel and paired with a smooth mid-length gas system this upper is an excellent choice for training defensive use and general-purpose AR-15 builds. This is a complete upper meaning it ships with a Faxon Superfinished M16 Bolt Carrier Group (Nitride) and a MIL-SPEC charging handleso you can mate it to a compatible AR-15 lower and get running quickly. This model uses a standard A2 flash hider and a Faxon low-profile fixed gas block (non-adjustable). Specifications for Faxon Firearms Match Series AR-15 6mm ARC 16in Upper Receiver: Manufacturer: Faxon Firearms Caliber: 6mm ARC Overall Length: 25.25 in Barrel Length: 16 in Barrel Profile: Gunner Barrel Twist Rate: 1-7.5 Firearms Threads Per Inch: 5/8x24 Color: Black Gun Model: AR-15 Fabric/Material: Stainless Steel Handguard Length: 15 in Gun Make: AR Platform Flutes: No Package Contents: Faxon Firearms Match Series AR-15 6mm ARC 16in Upper Receiver What firearm models does the manufacturer say Faxon Firearms Match Series AR-15 6mm ARC 16in Upper Receiver is compatible with? The manufacturer suggests that Faxon Firearms Match Series AR-15 6mm ARC 16in Upper Receiver is compatible with AR-15Faxon Firearms FX-URG-M6A16GA15-C: Match Series AR-15 6mm ARC 16in Upper Receiver Gunner Mid Length 1-7.5 Twist 5/8x24 w/BCG Black