One should understand our “teachers” on firearm accuracy are nothing more than shills for the firearms industry. We all read these articles which are nothing but advertising, and over the decades, the writers have gotten better in the mis use of statistics to hide the inherent accuracy of the item under test, and to prevent comparisons between tests in previous articles. Gunwriters don't want to exhaustively test the weapons they are given, for a number of reasons. The first is time and materials. Gunwriters are given a flat fee for their articles, DPris said it was $400. I think he took that down because I could not find that later. It is obvious, the less the influencer shoots, the more money they get to keep. Shooting takes time, the less time at the range the more time on the recliner, etc. Based on the compensation rate DPris stated, I think it is probable that articles are in fact a loss leader for many writers, and that they are only doing it for promotion of “their brand”. Book sales and celebrity endorsement are probably the big money makers for these guys. It is obvious the in print guys are not interested in shooting enough ammunition to establish the inherent accuracy of the thing, one reason is, because the inherent accuracy of the thing may not meet the communities' expectations. And that would upset an advertiser.
You do know, magazines don’t make their money on subscriptions. This is the business model since the 1880 and the Lady’s Home Journal. The subscription is more or less, earnest money. The subscriber has some skin in the game. The magazine makes its profits from advertisers. A magazine will absolutely do nothing to upset an advertiser.
The accuracy analysis we read in firearms “evaluations” is statistical pseudoscience. Gunwriters post the smallest group size out of three shots, and then claim an “average” group size. Notice they are no longer posting the largest group. Averages are not good measures of consistency. Averaging makes the group size appear smaller. The extreme spread of is the size of the largest group. You hit or miss based on the extreme spread of the group, not some average.
Perhaps the best measure of accuracy and consistency is the mean radius figure used by the Department of Defense. However, I don’t think in terms of mean radius. This year I was looking over the shoulder of a Smallbore National Champ as he showed us the results of 22lr lot testing at Laupa. The composite group sizes, on the best lots, were statistics on 40 shots. The number this guy was pointing at was extreme radius. That is the furthest any bullet was from center. That is a good number. As a point of discussion, I will use the diameter of the A23 target X ring. The A23 is a 50 yard target and the diameter of the X ring is .39 inches. The diameter of the ten ring is .89 inches. Any shot more than 0,445 inches from center is going to be a nine. Obviously that would be bad if the inherent accuracy of your ammunition will not hold the ten ring. If no rounds exceed 0.195, (half the X ring) then it is possible, if you do your part, to shoot a 50-5X on all four 50 yard bulls, resulting in a perfect score of 200-20X. That would be good.
There is an excellent article at the end of the Oct 2014 Shooting Sports USA on group size and accuracy:
http://www.nxtbook.com/nxtbooks/nra/ssusa_201410/ This foundational article was written by small bore prone competitors who wanted to shoot perfect scores. In small bore prone a Match is a 40 shot event of two twenty shot targets. The typical 1600 round Smallbore bore prone tournament is 160 rounds fired for record, divided up into four 40 round Matches. Therefore the referenced article assumes that a 40 round group is the baseline.
As anyone can see in table six, at least at 100 yards, a five shot group is 59% of the size of a 40 shot group, a 10 shot 74%, and a twenty shot 88%. A three shot group is below contempt.
This is another good article on the limitations of five shot groups
Accuracy Testing: Shortcomings Of The Five-Shot Group
by Brad Miller, Ph.D. - Wednesday, September 25, 2019
https://www.ssusa.org/articles/2019/9/25/accuracy-testing-shortcomings-of-the-five-shot-group
one that addresses statistics for accuracy.
Shot Group Statistics for Small Arms Applications
https://apps.dtic.mil/sti/pdfs/AD1034885.pdf
you may have to go to the main DTIC web site and then find it, as Government web sites are consistently changing and churning.