CMMG Multi Role Contour Barrel Sub-Assembly .300 AAC Blackout 12.50"

Ideal for crafting your personalized AR-15 upper assembly, this product features a meticulously installed M4 barrel extension, ensuring optimal performance and reliability. Each barrel sub-assembly is expertly head spaced to guarantee precision and safety, providing you with a solid foundation for your custom build.Multi-role profile4140 chromium molybdenum steelInternal and external surfaces feature a salt bath nitride finishTwist rate - 1:7Chamber for .300 AAC BlackoutThreaded 5/8-243/4 inches gas journal