SIG MP41

SIG MP-41 Neuhausen Submachine Gun - also referred to as just SIG MP-41 - is a Swiss submachine gun designed by Schweizerische Industrie Gesellschaft in 1941. It was one of submachine gun candidates for Swiss Army during World War II, but was not chosen. Instead, the Furrer MP41/44 was adopted, mainly due to Colonel Adolf Furrer's influence in the Swiss Army at the time.
The MP41 is an extremely rare firearm, with only about 200 samples ever produced.
History.
At the onset of World War II, Switzerland had declared neutrality in the fast escalating conflict. The prospect of potential invasion by Nazi Germany was a real possibility and in preparation for such scenario, the "Kriegs Technisch Amt", sent out an ordnance survey to Swiss Army in May 1940. Upon reviewing the results, the outfit found that the Swiss Army had less than 500 submachine guns at their disposal and the matter needed to be rectified urgently.
The Swiss army commissioned SIG and W+F Bern, then the two of the largest domestic small arms produces in Switzerland, to create new submachine gun prototypes for the Army. 
For Swiss Army, SIG developed the MP-41, which as an evolution of the SIG's prior MKMO submachine gun platform.
Like the MKMO, the MP-41 retained the swiveling magazine housing that folded horizontally into a groove in the fore-end. A prototype of without this feature was also designed.
Tests.
In 1941, the submachine gun trials were hold and SIG submitted a batch of 50 units for testing. SIG's competitor was the 
W+F's Furrer MP41/44. The submachine gun trials were derailed by Colonel Adolf Furrer's influence and due to his actions, the Swiss Army ended up choosing the Furrer MP41/44 over SIG MP41. SIG attempted to market the MP41 abroad, but were blocked from doing so by Switzerland's neutrality laws. 
Only 200 MP41s were produced before the design was abandoned.