Never fired a sten but remember someone saying a foot on the webbing helped to stop it becoming an anti aircraft weapon.
When I worked for the plod I did manage to get a few rounds down a range with an MP5, lovely although I did get my one and only misfire. Thought due to the cost saving practise of using reloads for range work. Didn't tell the Sgt I had most than just a little background and he was impressed that I got all rounds in the circle, so was I, had been some 12 years after I had used a Mk4.