Not necessarily. Practically speaking, there are so many factors that come into play, especially at distance, that you shouldn't take the 100y groups at face value and assume its going to hold true at all distances. You could have a rifle that, mechanically speaking, its capable of shooting 1/4moa at 1k, but the combination of rifle, ammo, environmentals (aka WIND), and shooter make it a realistic 1/2 moa. Also, some loads in rifles need to "settle" and you may see an instance where a certain load/rifle combo prints a 1 inch group at 100 yards, 1 inch at 200, and 1.5 inch at 300, 2ich at 400, etc... So at 100 yards, you are able to hold roughly a 1MOA circle, but as the round stabilizes you end up with being able to hold 1/2 MOA circles at further distances. Also, I'm well aware of MOA and MIL being an angular measurement. That said, its common to measure targets and group sizes based upon said angular measure as it shows precision or size relative to distance.