Great job on the HOA; I went out to Thibodaux this past week and Guy stomped my back side (10% of match) and Jeff also nudged me (2 Match Points). I am a bit rusty, but I attribute the whooping to the excellent progress made by these other folks. . . .come on, I take a couple of months off and when I come back everyone is shooting like GMs! Good on them, no doubt!
I have experienced the same thing regarding the 0.1 - 0.2 grain variation in .223. I always thought I was crazy, but I have witnessed that at the range of 200 yards, the variation does not cause much vertical stringing (though I am seeing a 30 fps standard deviation in my loads). I suspect that if we push that range out to 600 yards, we would see more pronounced evidence.
I tried to improve the dillon 550 powder measure by adding the micrometer and polishing all the surfaces and I am pretty happy that it is throwing Varget with about .2 grain range on 223. I just started messing around with 308, and the variation there seems to be larger.
I am beginning to think that it is an uncertainty in terms of percentage. When reloading 9mm with 4.1 grains of N320, a 1% variation is less that 0.1 grain, not even noticeable on my scales. When messing with 223, 1% is around .2 grains. By the time you get up to 308 and are putting 45 grains in, if you are varying 1%, you are off by nearly half a grain.
That is why I am interested in improving my drops some.
On your being anal, don't sweat it, I am the same way (engineer); everything on my desk is at right angles all the time!