The point of this thread was to help members understand that MOA is angular and is not simply a synonym for “inches.” I do not assume that everyone is incorrect. I am certain there are some people who understand MOA, but have slips of the tongue. However, I commonly observe people talking about MOA without any understanding of its angular nature; they incorrectly believe that MOA is a word that the shooting community uses to say how many inches wide their group was.
I did not say that “Angles become invalid at extreme ranges.” I said that “The PRACTICALITY of MOA becomes invalidated when we work at extremes...” The practical aspect of MOA being that if my rifle shot a 1” group of three shots at 100 yards (1 MOA), I can expect that rifle to shoot a 2” three shot group at 200 yards (1 MOA). Whether that perfect 2” group actually happens does depend on other factors (environment, human, etc), but I can reasonably expect a 2” group at 200 yards. Any variation is due to variables (rifle barrel temperature, a slight change in humidity, wind, etc) whose effects become more pronounced at distance. This example is a practical and reasonable application of MOA if I’m shooting a .308. Where MOA’s practicality becomes invalid is at the extremes... at a point, due to the inherent ballistics of that .308, that bullet will stop moving so to expect to achieve any group beyond that range is impractical and, therefore, the PRACTICALITY of MOA is invalid.
And yes, I completely understand that there are environmental, ballistic, and other factors that will become more noticeable to groupings the further the target is from the rifle. This is where theory meets reality. The theory and what happens if your rifle were to shoot bullets not impacted by ballistic coefficients, environmental factors, and shooter capabilities is that the rifle will shoot a certain MOA at all ranges. I am confident that we all understand that reality often does not precisely reflect the theoretical.
The bottom line is that to clearly convey performance and to speak precisely, distance to target, number of shots in the group, and the spread of the group need to be told.