Geissele Chrome Lined Heavy Profile Barrel 5.56 NATO 14.5 inch .750in Gas Journal. Our barrels are High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI). The accuracy and reliability of Geissele CHF barrels makes them an ideal choice for a hard use duty weapon precision tuned competition gun and everything in between. Specifications for Geissele Chrome Lined 5.56 NATO Heavy Profile Barrel: Manufacturer: Geissele Caliber: 5.56x45mm NATO Barrel Length: 14.5 in Gas Block Journal Size-Diameter: .750 in Package Contents: Geissele Chrome Lined 5.56 NATO Heavy Profile Barrel Geissele 05-3281: Chrome Lined Heavy Profile Barrel 5.56 NATO 14.5 inch .750in Gas Journal