Sondergerat SG104 "Munchhausen"

The Sondergerat SG104, nicknamed Munchhausen, was a German prototype recoilless gun of 355.6 millimeter, or fourteen-inch, caliber, designed from 1939 by Rheinmetall-Borsig on government orders to let aircraft attack the thinner deck armor of enemy warships. The gun was meant to be carried by a bomber diving steeply, between fifty and eighty degrees from horizontal, and fired at altitudes between six thousand and two thousand meters, and ground tests suggested the design would recoil very little. Flight trials beginning in September 1940 on a Dornier Do 217 instead found that the backblast of the weapon seriously damaged the test aircraft, and after further unsuccessful attempts through 1941 the project was abandoned in favor of air-to-ground rocket weapons.