How about a personal favorite, getting grit stuck under the extractor star, causing the cylinder to bind?
They never should'a stopped making swords.
[like these...and they laughed when I asked for a bayonet lug..!]
....and of course, Squantos' personal favorite...borrowing a revolver from Eaker!
Not an expert, but ...
Look if you are afraid of a gun jamming - then have TWO guns! Geeze - you figure if your life depends on it...
Actually, although I do love my 10mm Glock, I will confess that my nighttime self-defense gun is a heavy-duty (Astra 960) .38 revolver. ($100) It is in perfect mechanical shape, and is a very good and accurate shooter. I keep it very clean, check it periodically for rust, etc. and keep a full speedloader and a box of bullets next to it. No grit under the extractor or timing problems with that gun!
If I need it, I am pretty confident it will go bang.
That's my ugly work gun. The other XX guns I have are for fun!