LonelyMachines brings up a really good point: the reason .22 is less reliable than .25 isn't just that it's a rimmed cartridge instead of a semi-rimmed one, but because the priming method is more prone to failure. I seem to recall from somewhere that the Swiss Vetterli had dual firing pins for that very reason. I can't see that peculiarity being replicated in this day and age for anything other than the neato factor ("dude, what's up with your brass?"), but now I want a .22 pistol with dual firing pins.
Interesting food for thought. Yet another reason that, for serious social work, rimfire technology is more dead than Dillinger.
(Oh, and completely as an aside, in this age of doom and gloom, it's nice to read something optimistic for a change.)