The High Standard HDM is a semiautomatic pistol equipped with an integral sound suppressor. Based on the High Standard HD model target pistol, it was adopted by the Office of Strategic Services (OSS) during World War II. OSS head Bill Donovan demonstrated the pistol to President Franklin Delano Roosevelt inside the Oval Office. Because of legal concerns during wartime, full-metal-jacketed .22 LR rounds were developed for this pistol.