In this thread:
I described a shooting I was involved in. Note that I fired twice at the gunman, one round missed him and one round hit him dead center and exploded inside his heart.
No one knows which round stopped him, first or second, but another officer might not be alive today if I had only fired once and that was the one that missed.
As a shooter with vast experience in both the military and law enforcement, I always expected that if I shot at something, I would hit it..... all my training reinforced that thought. But real life situations have a dimension all their own that no training range can duplicate; I had just been shot at, bailed out of the house and saw the subject getting ready to shoot again. I am sure that adrenalin played a major role in the fact that one round did not hit him.
I am a firm believer in training and range work that is as close to 'real life' as it can be. I fire multiple round shot groups because I train that way. I also shoot the exact same ammo on the range that I carry with daily.... Speer Gold Dots. Sure it's more expensive, but because I shoot multiple round shot groups, I know exactly what the recoil of my weapon is like and how that effects the handling between one, two and even three rounds fired in very fast succession.
To illustrate this point: the next time you go to the range, mix your ammo as you load your magazine or revolver. By mix, I mean if you use a different range ammo just because it is cheaper, put both that and your carry load in without looking specifically to see which kind of round went in what order. Then squeeze off multiple round groups in quick order. Your target will tell the story. If you see a round or two way out of place, it will most likely be your better carry ammo because you were not as 'used to it' as you are the cheaper practice ammo.
Just something to think about, and I fully realize that other opinions may differ, as opinions are often based on personal experience.