Faxon Firearms Match Series AR-15 6.5 Grendel 16in Upper Receiver Gunner Mid Length 1-8 Twist 5/8x24 w/BCG Supressor Black. 5 Grendel barrel is built for shooters demanding lightweight handling sub-MOA accuracy and reliable mid-length performance. The Gunner profile combines the strength of the Government contour with the agility of a Pencil profileperfect for precision and field use alike. Machined from 416R stainless steel with 5R button rifling and treated inside and out with salt bath Nitride this barrel balances long-term durability with match-grade precision. A Nickel Tefloncoated M4 extension ensures smooth feeding corrosion resistance and a tight receiver fit for improved accuracy. Specifications for Faxon Firearms Match Series AR-15 6.5 Grendel 16in Upper Receiver: Manufacturer: Faxon Firearms Caliber: 6.5mm Grendel Overall Length: 25.25 in Barrel Length: 16 in Barrel Profile: Gunner Barrel Twist Rate: 1-8 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 6.5 Grendel 16in Upper Receiver What firearm models does the manufacturer say Faxon Firearms Match Series AR-15 6.5 Grendel 16in Upper Receiver is compatible with? The manufacturer says that Faxon Firearms Match Series AR-15 6.5 Grendel 16in Upper Receiver is compatible with AR-15Faxon Firearms FX-URG-M65G16GA15-C-SR: Match Series AR-15 6.5 Grendel 16in Upper Receiver Gunner Mid Length 1-8 Twist 5/8x24 w/BCG Supressor Black