This is always a fun topic! After many years of NRA Bullseye using a Ruger Bull Barrel 22 semi-auto I am of the opinion that a good ten shot 22 caliber will work well for home defense. Very little recoil and ten little bullets into one small circle beats the heck out of the wild 40 caliber shots all over the house. If you can shoot it is lethal for protection. Your thoughts?