With any .22 rimfire, shot placement would be absolutely crucial to guarantee an immediately fatal or disabling wound against a human attacker. Due to the need for a quick response under the duress of combat, the ability to concentrate on such precise shot placement is unlikely. Essentially, even though a hit with a .22 is better than a miss with a .44, you still want a lot more gun, as much as you can effectively handle, than the absolute bare minimum. At least I do.