That's not a front sight on the Liberator, it's actually a "Nostril Flange" to hold the barrel in place when you stick it up the nose of an unsuspecting German sentry.
Yes, but when one reads first-hand accounts from the NW Europe campaign the theme of jamming Stens recurs often ; not something one tends to find often in German or US memoirs.....
Actually, you find quite a few anecdotes about allied soldiers dismissing the MP-40 as being jam prone after firing it by gripping the mag, with later commentary (from others) that gripping an MP-40 by the magazine will create jams by altering the feed angle as the gun rocks from firing. The German soldier was taught to grip it by the sleeve into which the magazine is inserted, to avoid just that problem. I don't know if the Sten has the same peculiarity or not, but our own George Patton commented in another thread about the poor magazine design of the Sten which feeds the rounds from its double column into a single column as it enters the action. This increases the amount of friction which the magazine spring has to overcome, and contributes to malfunctions. The later Sterling (which is just a gussied up Sten), has a more typical double column magazine and much fewer problems.
...and of course, if the firer doesn't grip the Sten by the magazine, it increases the chance of a stray finger being inserted in the ejection slot.....
I heard a story from a Resisitant who mentioned a man being killed by his own Sten. The man was cleaning it, It fell on the floor and it started shooting until the last round. The man was hit on the legs , fell and was killed beofre he had a chance to stop the damned thing. This may be rather rare, but the reputation it gave to the gun made it quite scary for its users .
This guy is demonstrating the proper grip. In war movies they always grab the mag and swing it laterally to mow down Germans like wheat before a scythe. I suspect, held properly and fired in short bursts, the user probably had relatively few complaints, and more fingers.