Re: Is +/- .3 close enough for stick powders?
I think it depends on the case capacity. For a .223, it could be very significant, for a .338LM, less so.
I use the Dillon 550 and its measure. I set the charge a little heavy; enough to ensure that <span style="font-style: italic">every</span> charge will be at least on or over. I then dump the charge into a scale, pinch some out, and finger trickle some back until the charge hits my desired value. The remainder of the pinch goes back into the top of the hopper, and the corrected charge is returned to the case using a drop tube.
That's for bolt gun match loads. For semi's, especially non-match loads, I will run ten sample cases, weigh the collected charges, and correct the measure until the average individual charge weight is right.
I then run the press in progressive mode. Honestly, it can take some time to set the measure up just right; but I do it for safety, as well as accuracy, reasons. If I didn't want to be at least that close to ideal, I'd really not have a good motivation to handload.
But I also make a serious effort to load with a consistent rhythm and operate each stroke with as close to identical force as possible, to reduce operator-induced charge weight fluctuations.
In truth, I mostly make my ammo to meet match requirements.
I spent a lot of time using ball powder, W748 to be specific, as an effort to deal with alleged stick powder metering problems with my Dillon measures. The loads just wouldn't hold accuracy across real world conditions. I have since reduced my powder selection to Varget, H-4350, and H-4831SC. Using my above methods, their metering works as well as I'd ever need.
Greg