Following the adoption of the WF Bern MP41/44 by the Swiss military, SIG continued to develop its own submachine gun design in hopes of outside commercial and military sales. This is the MP48 pattern, which is a simplified blowback action, but using the same basic receiver geometry as the MK series from the 1930s. The receiver was cast or forged and left with a raw rough texture to reduce costs, and this pattern offered a wire collapsing stock in place of the traditional full wood stock. It also simplified the rear sight to a 4-range rotating set of notches instead of a tangent leaf. The barrel is only 200mm (8”) long, and uses essentially a K31 rifle front sight. The only significant sale of these was to Chile, and it was followed by the SIG 310 model which replaced it wooden furniture with polymer (although the was equally unsuccessful commercially).