LBE Unlimited Cold Hammer Forged AR-15 13.7in Barrel 556NATO 1-7 Twist Black. The durability" reliability and excellent build quality of these parts will ensure years of service you can count on. LBE Unlimited AR barrels are a cold hammer forged" melonite finished" offering that will suit your next build or existing AR platform with the performance you expect. This LBE barrel features a 1:7 twist barrel" pistol length gas system" an over all length of 7.5" and finished with 1/2X28 muzzle threading. Specifications for LBE Unlimited Cold Hammer Forged 556NATO Barrel: Manufacturer: LBE Unlimited Color: Black Finish: Melonite Black Caliber: 5.56x45mm NATO Barrel Twist Rate: 1-7 Gun Make: AR Platform Gun Model: AR-15 Additional Features: Barrel Case Finish: Melonite Handle Color: Black Features of LBE Unlimited Cold Hammer Forged Barrel 556NATO: Cold Hammer Forged Package Contents: LBE Unlimited Cold Hammer Forged 556NATO Barrel What firearm models does the manufacturer say LBE Unlimited Cold Hammer Forged 556NATO Barrel is compatible with? The manufacturer suggests that LBE Unlimited Cold Hammer Forged 556NATO Barrel is compatible with AR-15