Powder charge increments <.5 grains
This is as much about arithmetic as shooting.
6.4.5 THE ASTOUNDING POWDER MEASURE TEST! demonstrates that, depending on the measure and the powder, powder charges vary about .1 grain.
In a .1 grain increment world, a charge of, for example, 22.7 grains, is a statement that there is SOME difference between 22.7 grains, 22.6 grains, and 22.8 grains. (More precisely, the “domain” of 22.7 is from 22.65 + a smidgen to 22.75 – a smidgen.)
If there is, it would require very large sample sizes to be confident of the difference.
In a .5 grain increment world, a powder charge of 22.5 grains is a statement that there is SOME difference between 22.0, 22.5, and 23.0 grains. (More precisely, the “domain” of 22.5 is from 22.25 + a smidgen to 22.75 – a smidgen.)
If there is, it would require small sample sizes to be confident of the difference.
The 22.7 charge is an arithmetic statement that’s close to impossible to prove.
It may be reasonable, and is easy, to throw charges in increments of .25 grains. I set the measure to throw two charges that together weigh 44.5 grains, so one charge weighs 22.25 grains. I haven’t detected a reliable difference in accuracy yet but remain hopeful.
Threshold: Any reasonable powder measure and scale-beam balance-will throw acceptable charges. My experience with electronic scales has reinforced my good opinion of about any beam balance.
