The Atmed Manufacturing Co. produced a modified Hyde Model 35 submachine gun in the late 30's. It was tested at the Aberdeen Proving Grounds in September 1942. About 750 rounds were fired from 20-round magazines and it functioned poorly. The primers were pierced by the firing pin and the sear spring was too weak, causing the single-shot mode to give out 2 or 3 shots instead. When the pin was shortened by 0.009 inches the problems disappeared. It functioned especially well in mud and dust tests but it was considered not worth developing any further.