How an MP 40 works

The MP 40 (Maschinenpistole 40) was a submachine gun chambered for the 9×19mm Parabellum cartridge. It was developed in Nazi Germany and used extensively by the Axis powers during the Second World War.

Designed in 1938 by Heinrich Vollmer with inspiration from its predecessor the MP 38, it was heavily used by infantrymen (particularly platoon and squad leaders), and by paratroopers, on the Eastern and Western Fronts. Its advanced and modern features made it a favorite among soldiers and popular in countries from various parts of the world after the war. It was often erroneously called "Schmeisser" by the Allies, despite Hugo Schmeisser's non-involvement in the weapon's design and production. From 1940 to 1945, an estimated 1.1 million were produced by Erma Werke.

https://en.wikipedia.org/wiki/MP_40

MP 40: full disassembly & assembly
https://www.youtube.com/watch?v=NlHj3nEg0v0

This video was made with the help of the game World of Guns: Gun Disassembly:
http://store.steampowered.com/app/262410/

Видео How an MP 40 works канала Si vis pacem , para bellum.