Quote Originally Posted by BehindBlueI's View Post
A .22 is better than nothing, will probably work, but isn't ideal. I must have missed the part where he said it was more lethal than a 9mm. Odd.
^This is my perspective on .22 for SD.

An additional reason I wouldn't use it--at all--is I have yet to see any of my semiauto .22 rifles or pistols that are anywhere near the minimum threshold of reliability I'd expect in a SD weapon. I think that .22lr rimfire in semiautos is just inherently unreliable and more likely to have failures to fire, failures to feed, etc.