I got a pretty good powder measure, some kind of RCBS .Using stick type powder I never trust it. Nothing to do with the powder measure but rather the way the kernals fall into the powder hopper. You can fill the hopper and then bump it a couple time and make the weight change. Not for me, I weight every load with stick powder. Ball powder measure's much better and once I get the thing set I throw 10 loads and weight them. They need to come out real close to ten time's one charge or I don't just throw them. Flake powder is in it's own world. Only reason to weight it is to set the measure! I don't weight handgun loads other than to set the powder measure.
There is a lot of math being presented by folks probably better at it than me, but I have an observation/question on Don's post above that I'll throw out for thought:
If the issue is that variations (by weight) in the dispensing of powder charges is or may be a problem, I can't see how dispensing ten charges into a single batch, then weighing the whole thing, can in any way give confidence that there are not big variations by weight in each charge thrown. It would seem that this approach would actually mask that problem. If the measure was to vary by +/- two grains on every thrown (an extreme example of course) and you threw 10 charges, you could get a perfect "ten times" the desired target weight when you weighed them all due to the large sample size. If you weighed 20 charges in bulk and divided by 20 your measure would look even more perfect.
I may have misunderstood what Don meant. Maybe this is just how he checks to make sure he has his measure adjusted correctly, before he starts dispensing, in which case I would agree, that's a nice easy way to check it. But it would seem the worst way to check for variation.
Like him, I typically weigh all my stick powder charges (I have the time), but will throw spherical powders straight into the cases when loading a lot of them. I get everything dialed in and have at it. Every tenth charge, I drop it in the pan and check it on the scale, just to make sure nothing has "slipped."
Cheers,
Rex
