Early model Sten guns had questionable reliability, mostly based on who built them. Probably got something to do with the haste at which they were being built. Later models, once the apparent threat of invasion (although, realistically speaking, there wasn't much of a one) the Sten gun became a much more reliable weapon. Like the Bren, versions of the Sten kicked around forever. Special versions, you might be interested to know, were supplied to US special forces in Vietnam.
The lasting problem was that if you dropped it whilst it was cocked, or even just placed it heavily on the ground, it would probably go off.
The StG, funnily enough, only gave Kalashnikov the idea - to use an intermediary round. The round used by the StG is what most influenced his design process. As for the weapon itself and it's operation, an AK pattern rifle is drastically different to that of the StG - even if they do look a little similar from the outside.










