Loading black powder, a couple /10's don't change the loads like smokeless does.
I use my old Redding for just busting the bowling pin hanging at 200 yards and even at the gong shoots when I have to reload at those matches when I run out of shells. This old powder drop has served me well since the maybe late 50's and it's well worn. It will drop very consistent within 2/10's if used properly.
But when I load for a match I will drop it in a pan and weigh the drop and I will sprinkle some like a pinch of salt with my fingers or take a pinch out of the pan :D it's like the blanky thing this little guy uses for security :D
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As far as the burn rate question.
Black has a burn rate it's just very fast and this is why they rate it as an explosive. The smaller and thinner the you spread it the slower it burns like a fuse. You pile it or confine it, it will blow. The larger the granulation the slower that burn rate
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