In 2003 Smith Enterprise Inc. created its version of the M14 Enhanced Battle Rifle known as the MK14 Mod 0, type SEI. The rifle used a medium heavy weight 18.0" barrel and was used as a basis to create the US Navy's Mark 14 Mod 0 with Springfield Armory, Inc. being tasked to supply the necessary machinery in cooperation with the Naval Surface Warfare Center Crane Division. SEI builds an improved M14 gas cylinder as a component of their specialized rifles and a part for the military to upgrade older rifles. The gas cylinder is assigned the NATO Stock Number: NSN 1005-00-790-8766.