Originally Posted by jvon
A scale accurate to one hundredth of a grain , by itself is not the magical ingredient, how ever when you stack all the tolerances, ie case weight, case volume, bullet weight& bearing surface, pointing bullets to increase balistic coefficient, neck turning cases to insure consistent neck pressure etc. when you shoot at a thousand yds I know you won't believe but 1 or 2 granules of powder will show itself! At 100 to 500 yds you will never notice. One good example is trimming meplats and repointing the bullet. In my f class gun 7 WSM at 1000 yds a reprinted berger180 hybrid will impact 10" higher than an out of the box. This is because of the increased BC. The vertical is no big deal, but with that increase in BC the wind factor is reduced which is a big help at 1000yds.
I've never seen a situation with long range competition stuff that such attention to detail is needed. As brand new unprepped cases holding powder charges with a 2/10ths grain spread can shoot bullets right out of the box into 15-shot groups at 1000 yards measuring under 5 inches (equal to or better than all the high dollar benchrest systems) from a low cost target rifle with a standard chamber, I consider all that micro-management of such details a total waste of time. But it does make the doers feel good and have confidence in their reloads.
Even loading a few thousand new cases with metered 3/10ths grain charge weight spread and bullet runout up to near .004" shooting 20 shots inside 3 inches at 600 yards in several rifles with different bore, groove and chamber dimensions; all without all that frivolous stuff done.
In my own tests, there's more spread across primer's output in a given lot of them than a charge difference of only one kernel (granule) of powder causes as far as muzzle velocity is concerned. So does a 10% change in case neck grip on bullets and few folks measure that at all.
The above aside, if you and yours do no worse than 4.5 inches at 1000, then maybe you're onto something.