Rosco Manufacturing Bloodline .300 AAC Blackout Barrel 16 in Pistol Heavy 1-8 Twist 5/8x24 Thread Nitride Black. This is the shortest that Rosco Manufacturing will go to allow you the flexibility of a shorter Personal Defense Weapon (PDW) without sacrificing performance or ballistics. Rosco Manufacturing 300 Blackout barrels were created by using input from SOCOM end users and some of the original creators of this caliber. Every barrel was designed to optimize the original role for the 300 Blackout; to be suppressor friendly and accurate. It is Rosco Manufacturing goal to get you the performance that you seek out of these AR15 barrels when running sub-sonic ammo or supersonic ammo (depending on barrel length). Twist rates gas port diameters and lengths have all been taken into account when we set out to make these. Lets just say that Rosco Manufacturing dont like leaving things to chance. Specifications for Rosco Manufacturing Bloodline .300 AAC Blackout Barrel: Manufacturer: Rosco Manufacturing Color: Black Fabric/Material: 4150 CMV Material Caliber: .300 AAC Blackout Barrel Profile: Heavy Threads per Inch: 5/8x24 Barrel Material: 4150 Chrome Moly Vanadium Flutes: No Gun Make: AR Platform Gun Model: AR-15 Condition: New Gas Block Journal Size-Length: 0.75 in Gun Type: Rifle Country of Origin: USA Gas System: Pistol Length Features of Rosco Manufacturing Bloodline Barrel Heavy Profile .300 BLK Gas Block Size .750 Barrel Crown 11 Degree Package Contents: Rosco Manufacturing Bloodline Barrel Heavy Profile .300 BLK What firearm models does the manufacturer say Rosco Manufacturing Bloodline .300 AAC Blackout Barrel is compatible with? The manufacturer suggests that Rosco Manufacturing Bloodline .300 AAC Blackout Barrel is compatible with AR-15Rosco Manufacturing BL-16-HB-300BLK-8-P: Bloodline .300 AAC Blackout Barrel 16 in Pistol Heavy 1-8 Twist 5/8x24 Thread Nitride Black