Got to agree with Ichiban.
The reason the military went to 9MM had nothing to do with it's effectiveness and everything to do with politics.
The choice was made, against the advice of every one who actually had to use them, for purposes of interchangeability with the other, European, NATO members who think .32 and .380 are practical service rounds.
Look at the history, the military originally dumped the .38 because it did not do the job on Filipino rebels.
How is a 9MM, approximately the same bullet, at about the same speed, going to be any better ?
That is why over the last 11 years of actual combat use all military branches have been switching back to .45 as much as possible.
On the .22, great little round, inexpensive and fun to shoot.
For self defense it's better than nothing.
Yes people die from .22's, but the objective of SD is to stop the attack, what good is it to you if your attacker bleeds out 15 minutes after beating you to death ?