Before this thread gets anymore silly, let's examine 2 prominent deliberate killings involving the .22 L.R. cartridge.... One was an assassination, the other a mob hit. Robert F. Kennedy Jr. was assassinated by Sirhan B. Sirhan on June 5, 1968, in the kitchen of the Ambassador Hotel in Los Angeles, California. He was shot 3 times in the head, as close as an inch away. He lived through a 3 hour and 40 minute surgery, only to die nearly 26 hours after the shooting.
The mob hit was on Sam Giancana in the basement of his Oak Park, Illinois home on June 19, 1975. A gunman entered Giancana's basement kitchen and shot him in the back of the head with a .22 L.R. pistol of unknown type, as he was frying sausage and peppers. After Giancana fell to the floor, the gunman turned him over and shot him six more times in the face and neck. He died at the scene, never moving.
These 2 deliberate killings prove that while the .22 L.R. cartridge can be, and is in fact lethal, it is a horrible choice to use to try and stop someone who is attempting to do you harm. In Kennedy's case, he lived a full day before succumbing to 3 shots in the head at extremely close range.
In the case of Giancana, a .22 L.R. was used because of the noise factor. The mob doesn't like to attract attention when they're whacking someone. Still it took 1 shot to the back of the head, again at very close range, and 6 more shots to the head and face before the gunman was convinced the job was done.
And also remember that Robert F. Kennedy was a small framed, very thin man. And Sam Giancana was 67 years old, and had heart trouble. Not the hardest guys to kill in the first place.
So translating this into a self defense scenario, I really can't think of a worse cartridge to use for that purpose. Except for perhaps a .25 Automatic. There is no "good" .22 L.R. self defense cartridge, anymore than there is a good low fat grade of Prime Rib.