"Jams" stopping the gun momentarily, 20-1 autos vs revolvers. Utter mechanical failures, that stopped the gun for a length of time, exceptionally rare in either gun. You can usually muscle another shot out of jammed revolver, unless something mechanical broke, or, a weak load is stuck between the barrle and forcing cone.
One that stands out, the colleted bushing on a series 70 Colt Govt Model broke off one of its fingers. I would have sworn that gun had been welded together with the slide halfway back. It took serious pounding with a wooden mallet to knock it free. Gouged the crap out of the barrel and inside the slide. Replaced it with a solid bushing.