The MP-60 was Erma's third attempt to meet the specifications set by the Bundeswehr for a service submachine gun. It was designed in the spring of 1960 and it was unlike their previous MP-58 and MP-59 submachines guns which had been rejected by the Bundeswehr. The body was largely comprised of stamped metal and the Vollmer return spring assembly seen in the previous weapons was replaced by twin carrying springs that passed through the bolt to the front end of the body. The magazine was that of a Carl Gustav submachine gun. Twenty prototype MP-60 submachine guns were submitted to Bundeswehr trials in September 1960, and in the following 8 weeks another twenty were built. All forty of these weapons were hand-built, but the short time gap between the two batches made improvements for the seco