Originally Posted by cyphertext
He isn't asking about .22lr (long rifle), he is asking about .22 long. Different bullet, and no, probably won't work in a semi-auto pistol. It may feed ok, but typically the .22 long won't cycle a semi auto.
This pic shows the difference between .22 short, .22 long, and .22lr.
Great illustration. I can see there is a lot less powder in the .22long vs 22LR. So, even if the gun will autofeed, it may not have enough ummmphf to cycle the slide.