The German military began looking for a new submachine gun design in secret in the mid 1930s. There is basically no surviving documentation, but the main contenders appear to have featured: Hugo Schmeisser's MK-36,II and Erma's EMP-36. Today we are taking a look at one of two known examples of the Erma design at the VHU in Prague. Designed by Heinrich Vollmer, this is a plain blowback open bolt system chambered for 9x19mm. It is massively more complicated than such a simple design has any right to be, though. Elements like the tiny set screw holding together the recoil spring assembly and the detachable bolt face are, frankly, nutty to include in a prospective military design.

However, Vollmer's design had a number of external design features that were deemed very desirably by the German military. The pistol grip and very compact underfolding stock were both admirable, and the muzzle rest system was also of interest (ablating in a simplified form). Ultimately, the result of testing of the Erma and Schmeisser prototypes was a combination of their features into a hybrid design. The Erma provided the external form factor, and the Schmeisser contributed the internal mechanics for the MP38 and in turn MP40.

Many thanks to the VHU - the Czech Military History Institute - for giving me access to this fantastic prototype to film for you. The Army Museum Žižkov is a part of the Institute, and they have a 3-story museum full of cool exhibits open to the public in Prague.If you have a chance to visit, it's definitely worth the time! You can find all of their details (including their aviation and armor museums) here:

https://www.vhu.cz/en/english-summary/