 During World War I, the Germans experimented with machine pistols by converting both 7.63mm Mauser and 9 mm Parabellum semi-automatic C96 pistols to full-auto.In the late 1920s, Spanish gunmakers introduced select fire copies of the C96 with 20 round detachable magazines.In the early 1930s, Mauser engineers followed suit, and introduced the Model 1932 or Model 712 "Schnellfeuer" variant, which included 20 round detachable magazine and a select fire mechanism allowing fully automatic fire at a rate of 1000 rounds/minute.