Rainier Arms Ultramatch MOD2 .223 Wylde MK12 SPR Barrel 18in Nitride 1-7.5 Twist 1/2x28 Black Medium. They are able to reach our goal by sourcing a very high end barrel blank at an affordable price. They start off using a high precision match blank in 1:7.5 twist machine it to the highest quality you have a barrel that is the best value hands down in the industry. Specifications for Rainier Arms AR Ultramatch MOD2 .223 Wylde MK12 SPR Barrel: Manufacturer: Rainier Arms Color: Black Fabric/Material: Stainless Steel Caliber: .223 Wylde Barrel Length: 18 in Barrel Profile: M4 Gas System Length: Rifle Length Gas Block Journal Size-Diameter: .750 in Threads per Inch: 1/2x28 Barrel Twist Rate: 1-7.5 Flutes: No Gun Make: AR Platform Gun Model: AR-15 Weight: 2 lb Condition: New Package Contents: Rainier Arms Ultramatch MOD2 .223 Wylde MK12 SPR Barrel What firearm models does the manufacturer say Rainier Arms AR Ultramatch MOD2 .223 Wylde MK12 SPR Barrel is compatible with? The manufacturer suggests that Rainier Arms AR Ultramatch MOD2 .223 Wylde MK12 SPR Barrel is compatible with AR-15Rainier Arms RAB-UM2-223-18-R-MK12-NF-BLK: Ultramatch MOD2 .223 Wylde MK12 SPR Barrel 18in Nitride 1-7.5 Twist 1/2x28 Black Medium