Vey informative. Are those mean radius numbers must be under ideal or theoretical conditions? What about windage, air density variations, etc?
Actual test conditions at arsenals or other test facilities. Aberdeen is MD has some serious enclosed test facilities. Even some commercial bullet/ammunition manufacturers have underground tunnels in excess of 300m.
Not sure one can determine “theoretical MR”, as by definition is average distance from the center of a group-it is actually quite easy to determine- fire a group, then use a square to draw lines perpendicular to the outside impacts, then measure and the X and Y values of all the impacts to determine center of the group, then from tis point, measure to each bullet hole and average, that is the mean radius of the group. Of course, a three shot group touted by the gun rags tells you nothing statistically. The government uses groups of 100 or more... I use not less than 10 shot groups for the sake of time and barrel life: seems statisticians state 8 shots is the minimum to tell you anything reliable.
There is a smart phone app called RangeBuddy that allows you to photograph your group, determine a distance measure on the target for comparison, then mark the shots with icons, it will then determine MR, MOA, offset from aim point etc for free....