Some new shooters ask why they can’t just practice to shoot a human sized target for self-defense work because that’s exactly what they would be shooting in real life.
The usual gun store answer would suggest that not every part of the human body is a good hit. They suggest that if you shoot the bad guy in head or heart your bullets will be effective in stopping the lethal threat. While any other hit on the human body might eventually kill them but barring a psychological stop due to pain or shock it might not stop the bad guy from continuing to harm you. While this is certainly true, it is only part of the story.
Under stress, movement (often both you and the threat) degrades accuracy. Now a bullet that hit the outer edge of your human sized target on the range is a complete miss in real life because the bad guy moved a few inches while you were pressing the trigger. A good idea is to train to use a smaller sized target to compensate for this. Of course it’s a good idea after learning the fundamentals to practice shooting moving targets.
During real gunfights you might shoot too fast making your accuracy degrade even more. This sometimes occurs when you are shooting what you believe is a proper speed for a given distance to target. As I’ve mentioned before we are not good at judging distance when calm and we certainly are not good when in fear for our lives. Often the threat is farther than you think due to depth perception problems that have occurred to you as a normal biological response to the proximity to death. Because you are farther away in effect you are shooting too fast causing the inaccuracy.
Taking these phenomenon into account would suggest a person needs to shoot a smaller group of bullets just to hit the already artificially reduced target we mentioned before.
It is difficult to put a number on what size target you should use. You will have to decide for yourself. A Delta Force retiree who teaches gun classes nationally was the only person to ever give me a guess, and he emphasized it was an educated guess. He said that Delta tracked all their training rounds and tried their best to track the accuracy made on the enemy they shot, when safe to do so. He gave me a guesstimate of a 30 percent reduction in accuracy from training to combat. I’m not a special forces person and suspect my reduction in accuracy will be much larger.
I try to reduce my target size a minimum of 50 percent of a skinny person’s body and head. This is why a circle of 6 inches as a torso target and a 3 inch circle for a head target makes so much sense to me.
The small size of these targets are determining your accuracy standards for training. They determine the speed you can shoot at any given distance. Take the time to learn the needed stringent accuracy standards to help make sure your accuracy is good enough after it deteriorates in a real life shooting.