The problem that most readers have with using a 22 long rifle bullet is not so much as the stopping power of this caliber against the perp but more of a reliability factor. Most every one knows that the rimfire is a very deadly round for its size, but there are to many failure to fire with rimfire bullets. If you are already under extreme duress because someone has broken into your house and you are awaken suddenly, or someone has attacked you without provocation, do YOU want your first chance that you get to shoot your weapon in self defense to have a failure to fire because the rimfire casing did not discharge? Now you have to clear your weapon and fire again while someone is slicing and dicing you best case scenario, or someone is shooting at you. You now shoot this individual with a caliber that is a deadly caliber but in the meantime it could take several minutes for the person to bleed out if your shot happens to hit an artery. A cns shot is the only shot that may stop him on his tracks. I'm retired military and have seen in Africa, and the middle east that some of the guys that are high on drugs you can empty a magazine whether it's 5.56, 7.62, or 45 cal, or 9mm into them and they still keep coming. You must decide what is best for you and how capable you are in defending your self. Your better off shooting a 22lr if you are accurate with that pistol and hitting the perp with the 22 than using a 454 casull and missing the perp because of recoil. The pucker factor is something most people never experience or expect and it is not easy to control you can actually miss from two feet away. Unless your are cool under this conditions regardless of the training you will never be as prepared as you think you might be.