Here's an article from Guns & Ammo about this:
Practical Handgun Accuracy
Here's an excerpt from page 2 of the above link:
"The best approximation I can reach is an old standard that goes back to my practical shooting days. Back then we used it for minimum gun accuracy; now I am relatively comfortable with the concept as a definition of suitable shooter skill. We call it minute-of-handgun accuracy, or one inch for every 10 yards of range—that is, five inches at 50 yards or 21⁄2 inches at 25 yards, etc. If you can step up and produce a three- or five-shot group or, better yet, consistently hit a target that size, you will stand in pretty good company."
Practical Handgun Accuracy
Here's an excerpt from page 2 of the above link:
"The best approximation I can reach is an old standard that goes back to my practical shooting days. Back then we used it for minimum gun accuracy; now I am relatively comfortable with the concept as a definition of suitable shooter skill. We call it minute-of-handgun accuracy, or one inch for every 10 yards of range—that is, five inches at 50 yards or 21⁄2 inches at 25 yards, etc. If you can step up and produce a three- or five-shot group or, better yet, consistently hit a target that size, you will stand in pretty good company."
