The M-28 or M-29 Davy Crockett Weapon System was the tactical nuclear recoilless smoothbore gun for firing the M388 nuclear projectile armed with the W54 nuclear warhead that was deployed by the United States during the Cold War. It was the first and at the time was the utmost important project assigned to the United States Army Weapon Command in Rock Island, IL. It was one of the smallest nuclear weapon systems ever built, with a yield of 20 tonnes of TNT (84 GJ).It is named after American folk hero, soldier, and congressman Davy Crockett.