Andrew recommends listening/viewing all the podcasts involving Mr. Miles.
3 and 5 shot groups are almost meaningless. A 20 shot group is a bare minimum to start drawing conclusions, and a statistician would ask for 30, 50, or even 100 data points. But the Hornady boys have done some extensive testing. See podcasts 50 and 52 for discussion of group sizes.
Brass prep is hardly worthwhile. Inside neck deburring has been shown to be a benefit. Flash hole deburring if it removes a big burr could be a benefit. Weighing and sorting brass or bullets is not beneficial. Try to get brass and bullets from the same lot.
Ladder tests to determine "nodes" actually fall apart when 20 point groups get used. With larger groups, you just get a linear relationship -- more powder gives more velocity. So pick a good powder and bullet, drop 1 grain from the max load and try it. Maybe try several candidate powders this way. Start with a 10 shot group and then shoot a 20 shot group to confirm the results, then load all your ammo for the season.
Miles says he seats with a .035 jump to the lands. Seating close can yield erratic results as fouling builds and some bullets touch and some don't. The main goal is to produce ammo that fits the magazine.
Quality barrels make a big difference. There are at least 10 quality barrel makers --
Bartlein, Shilen, Krieger, Benchmark, ...
MDT magazines were also mentioned for ARC, which implies
that their AICS magazines may also be good.
Rifle actions by Nucleu (American Rifle Company) and Impact (Impact Precision shooting) were mentioned -- I see prices from $1100 and up for Impact.
Tom's Computer Info / tom@mmto.org