In 1930, the Austrian police accepted the S1-100 as the
Steyr MP30, chambered for then standard Austrian
9×23mm Steyr pistol rounds. With the 1938
Anschluss between Germany and Austria, the German Army acquired most of the available MP30s and MP34s. A number were then re-barrelled to chamber 9×19 ammunition and issued to German troops as the
MP34(ö) –
Maschinenpistole 34 österreichisch (literally "Machine-pistol 34, Austrian"). in
9×25mm Mauser caliber. In
Yugoslavia, both the
Partisans and the
Chetniks used captured Solothurn MP34s carried by German and Croatian troops. Portugal bought in small quantities the
.45 ACP version and was adopted as
Pistola-metralhadora 11,43mm m/935. Portugal also purchased small quantities of the S1-100 in
7.65x21mm Luger calibre in 1938, and the weapon was adopted as the
Pistola-metralhadora 7,65 mm m/938 Steyer submachine gun. In 1941 and 1942, larger numbers of 9mm MP34 guns were delivered to Portugal by Germany. In Portuguese service, the 9mm MP34 was known as the
Pistola-metralhadora 9 mm m/942 Steyer. Many m/942 guns carry a Portuguese crest just forward of the safety mechanism in combination with
Waffenamt (WaA) markings. The m/942 remained in service with Portuguese Army into the 1950s, and was used until the 1970s by paramilitary and security forces in Portugal's overseas African colonies during the
Portuguese Colonial Wars. The
PAVN use this gun in the Vietnam war. ==Users==