A few years ago my cousin was the victim of a home invasion. The invader was mentally disturbed and kicked my cousins front door in in the middle of the night. The invader seriously injured my cousin before my cousin got loose and retrieved his 22 pistol from his night stand. One shot to the invaders head stopped the problem and the invader was removed in a body bag.

22 might not be the #1 choice but it will do in an emergency.