How Many Groups to Measure Accuracy?

[MarkL]

Thanks, Denton, that's good to know.

Do you have any thoughts on using the Averge Group Radius method? My gut feel is that it would take fewer groups/shots to get a result that is fairly close to the "long term average".

For those that are unfamiliar with AGR, you average the X and Y coordinates of each hole to find the group's center, then average the distance of each hole from that. Therefore, it takes ALL the holes into account, whereas the standard Extreme Spread method only takes the worst two into account.