Yankee Hill

Surface: Smooth - Length: 9.1 - Weight: 1.1 lbs. - Material: 4140 Chrome Moly Steel - Chamber: 300 AAC Blackout - Twist Rate: 1 in 8 - Chrome Lined: No - Finish: Melonite QPQ - M4 Feed Ramps: Yes - Muzzle Thread Pattern: 5/8-24 - Gas Port Location: Pistol - Exterior Diameter at Gas Port: 0.750 - This YHM barrel features a 300 AAC Blackout Chamber. Constructed of 4140 chrome moly steel with a threaded muzzle the barrel is Melonited for ultimate surface protection. The melonite coating provides a thinner surface than chrome-lining so bore friction is reduced for better accuracy. In addition melonite is harder than chrome-lining providing a longer wear life. - Our .300 BLK barrels are designed to perform with both subsonic (220 and 208 gr) and supersonic loads. The gas port has been tuned to lock the bolt open on the last round when using subsonic ammunition with a sound suppressor or supersonic ammo without a suppressor. The bolt may not lock back when using subsonic ammunition WITHOUT a sound suppressor installed. Please note that subsonic ammunition can be more prone to malfunction than supersonic ammunition. - The use of this barrel on an AR Pistol is legal but the use of this barrel on any AR15 rifle/carbine will qualify the firearm as an SBR and the firearm needs to be registered as such.