How to measure group size

by B.B. Pelletier

I’ve covered this material before, but it was long ago, and we’ve grown in readership lately. New shooters read about group sizes and assume there’s an accurate and foolproof way of measuring them. That’s simply not the case. The great barrel maker Harry Pope once spent half an hour with a magnifying glass and a caliper to measure the size of a group; and in the end, he revised its published size by about 1/64 of an inch! So, if a world-class marksman (he held several world records) and barrel maker has trouble doing it, what hope is there for the rest of us? I’ll address that question at the end of this report. read more