Springfield Armory Springfield Armory Echelon Handgun Barrel 9mm Luger 4.0C 1/2x28 Threaded Black. 0C pistol with a factory threaded drop-in barrel. Available in 9mm this threaded barrel features a black Melonite coating for rust-resistance and lubricity. The barrel comes with an included thread protector when not in use. For use in any 4.0 barrel Echelon pistol configuration. Package Contents: Springfield Armory Echelon Handgun Barrel 9mm Luger 4.0C 1/2x28 Threaded Black Add muzzle devices to your Echelon 4.0C pistol with a factory threaded drop-in barrel. Available in 9mm this threaded barrel features a black Melonite coating for rust-resistance and lubricity. The barrel comes with an included thread protector when not in use. For use in any 4.0 barrel Echelon pistol configuration. EC0901TBC-KIT