Ballistic Advantage BABL300002F: BA Hanson Profile barrels feature a shoulderless design, symmetrically limiting barrel \"whip\" and allowing the barrel to quickly return to its home position. This is extremely beneficial for follow up shots at a high rate of fire or full auto fire. Lightweight feel without the lightweight limitations, it is truly ideal for how an AR-15 is designed to perform. This 8.3\" Performance Series barrel is machined from 4150 Chrome Moly Vanadium steel with a QPQ corrosion resistant (melonite) finish. It features a FailZero nickel boron coated M4 feed ramp extension and is HP and MPI tested. It features Ballistic Adavantage\'s proprietary BA Hanson profile and includes a pinned lo-pro gas block. Note: Hanson barrels are not designed to work with aftermarket piston kits.