 The gun was rarely used in service, and its existence was kept secret until three years after the Armistice; in 1921 the Allied Control Commission finally became aware of the Gast gun when a cache of 25 of the guns, ammunition, and designs was found near Königsberg.Gast himself had applied for a US Patent in 1920, which was issued in 1923.A Gast gun was evaluated by the US Army and found to be reliable and mechanically practical.