Why is the standard deviation of group size a fraction of average group size?
Well, first off, because it is. The standard deviation of any distribution is a fraction of the mean. What I’m proposing here is that the standard deviation of group size is a CONSTANT fraction of the mean, and that that fraction varies with n. Then for any n = number of shots in the groups, the distributions are scale models of each other, varying with group size. I’m a little uncomfortable with this, because, as an example, the standard deviation of bullet weights seems fairly independent of mean bullet weight. Four hundred grain bullets vary +/- half a grain; sixty-grain bullets vary +/- half a grain. My weighing experiences tell me that the standard deviations of cast bullet weights is independent of bullet weight. However, for close average group sizes, it doesn’t matter. Then there’s the fact that the data are remarkably similar. My experience with Economic and gun-related data is that data bounces around furiously. This doesn’t. Looking at the rightmost column on each table show
