Rainier Arms Ultramatch MOD2 6.5 Creedmoor Barrel 26in Polished 1-8 Twist 5/8x24 Silver Medium. Their goal is to mass produce them to bring them to market at the most competitive prices. They wanted the best balance between accuracy while keeping the weight down as much as possible. Specifications for Rainier Arms AR Ultramatch MOD2 6.5 Creedmoor Barrel: Manufacturer: Rainier Arms Color: Silver Fabric/Material: Stainless Steel Caliber: 6.5mm Creedmoor Barrel Profile: M4 Gas System Length: Rifle +2 Length Gas Block Journal Size-Diameter: .875 in Threads per Inch: 5/8x24 Barrel Twist Rate: 1-8 Flutes: Yes Gun Make: AR Platform Gun Model: AR-10 Condition: New Package Contents: Rainier Arms Ultramatch MOD2 6.5 Creedmoor Barrel What firearm models does the manufacturer say Rainier Arms AR Ultramatch MOD2 6.5 Creedmoor Barrel is compatible with? The manufacturer says that Rainier Arms AR Ultramatch MOD2 6.5 Creedmoor Barrel is compatible with AR-10Rainier Arms RAB-UM2-65CM-26-R2-FF-POL: Ultramatch MOD2 6.5 Creedmoor Barrel 26in Polished 1-8 Twist 5/8x24 Silver Medium