BSW was the name of Simson from 1936-1939. The Simson's were forced to emigrate from Germany for religious reasons. The German government took the factory in 1936 renaming it Berliner Suhler Waffen (hence BSW) and again renamed it Gustloff Werke in 1939. So it's a German gun with Swedish steel. I would venture that the majority of steel production in those years might not have had the consumer as its primary customer, ergo Sandvik.