Modern ammunition made a major change in the mid-1980s as a result of a number of bad shootings. There is no doubt that a good load with enough power should help do the job. But I have seen a case where a felon took 19 rounds of .45 and still managed to fight on until he died. I've seen suspect shot in the head who have walked into an emergency room to complain about a head ache that would not go away. Unless someone gets a central nervous system hit...they are likely to be dangerous for some time. Some guys don't get the memo they are dead...and still hurt or kill people. For example the famous Miami shootout of 1980 with the FBI...one suspect took a .38 to his brain stem. He was all but dead when he killed to more agents. Eighty percent of people shot with a pistol round...survive it. And if you have to shoot it...twice is a good start. Handguns are a bad choice for personal protection...but at the same time easier and more practical to conceal or carry. The last officer at my department to be killed was shot with a .25. A lousy round. It was a hot summer night and he took his vest off before he was called to a scene. We found him at sunrise. He fell into a grassy area...flash light down...the suspect was a few feet to his right...and dead. Anyway. Whatever the nice people here do...get all the training you can...from someone who knows what they are doing.