The original design of this weapon was the idea of a French engineer, Louis Bonnet de Camillis, whose financier licensed it to Erma in 1956. Erma's prototype was known as the MP56 but only ten were made due to Erma's limited industrial capacity at the time. The rights to the design were then sold to Mauser, who produced their own version called the MP57. Efforts to market the weapon, both in Germany and abroad, were unsuccessful and only 25 were made before production ceased.
DesignEditStemming from the exact same design, the MP57 was operationally identical to Erma's MP56; it was a basic blowback-operated submachine gun that used a "wrap-around" bolt. The only major improvement Mauser made to the design was the inclusion of a fire selector. The MP57 featured a folding wireframe stock and a foregrip that hinged under the barrel. It fed from MP40 magazines.