For marksmen, the pursuit of accuracy never ends but the defensive shooter is concerned about sufficiency. Most shootings occur within 6 feet but does that mean that accuracy need only be sufficient for a silhouette target at 2 yards? Not even close.
Stress has both physical and psychological consequences. The defender may lose confidence but he may also lose peripheral vision, all hearing, ability to distinguish colors, awareness of surroundings, and bladder and bowel control. In exchange for that misery, he may gain a temporary palsy, runaway heart rate, mental confusion, profuse sweating, and an uncooperative mouth. So training standards must dramatically exceed statistical shooting averages. On top of all this, people don’t expand during fights to silhouette size, they shrink, Bodies hunch and bunch, and bad guys stand behind other people or objects. A six foot tall man may only present a 3″ x 5 ” target. Further, statistical norms aren’t guarantees. There’s a whole lot of shootings going on at two car lengths or more, which is just a normal parking lot distance.
Since a four inch miss at five feet (and sixty percent of all close range police shots do miss) becomes a fifty foot error after crossing a parking lot, how much accuracy should a defender train to achieve?
Start with the general shooting standard in the front of The Perfect Pistol Shot. You can get that for free off the amazon.com book page.
Accuracy is a moral and legal responsibility, its not a matter of personal choice.