[samatman]

Just to carry onwards with the use/mention distinction we're aggressively erasing here, you seem to question whether actual, real-life footguns exist.

They do! Here's a reference. https://en.wikipedia.org/wiki/Slamfire

Another common way to shoot yourself in the foot is a gun which will go off if you drop it. An example of a gun where early models were especially susceptible is the Lanchester: https://en.wikipedia.org/wiki/Lanchester_submachine_gun