weighing multiple charges vs one

[cletus9mm]

i've read in more than one place that it's "better", "more accurate" to weigh 4+ charges and then take the average of those "x" amount of charges and base your throws off of that number. can someone please explain to me why this may be the case. thanks in advance.

[Ronnie j]

I think you have to both, I weight a 10 count average and then make sure a get 3 or 4 indivual that are the withiin a tenth then load.

Edited November 6, 2010 by Ronnie j

[planenut]

If the scale has a .1 grain error and you are measuring 4.2 grains, you may be getting 4.1 to 4.3 and could be in error .1 either way.

If the scale has a .1 grain error and you are measuring 16.8 grains, you may be getting 15.8 t0 17.8 and could be in error .1 BUT... that would only be 1/4 the error at 4.2 grains. (.025 x 4 cases equal the .1 grain)

I don't know if that made sense to you or not? Measuring 10 cases at 42 grains would get you down to .01 error.

This is all assuming your powder drop is dropping equally each time..

Edited November 6, 2010 by planenut

[bbbean]

i've read in more than one place that it's "better", "more accurate" to weigh 4+ charges and then take the average of those "x" amount of charges and base your throws off of that number. can someone please explain to me why this may be the case. thanks in advance.

Basic stats - the larger the sample, the more accurate the measure.

[MARKAVELI]

once you have your decaping,belling,seating and crimping dies you gotta make sure your powder charge is at the charge you want,once you got it set at the charge you want throw 10 charges onto your scale then you will have a better idea of how +/- you are and might need to adjust. at times your powder charge will be +/- about a tenth. and also the powders you are using will have an affect, as well as how sturdy bolted down your bench and or your press is also you wonna have brass in all your stations if you are loading progressively so the multiple charges can give you an average of your powder charges! sorry for the run on, good luck!

[njl]

There could be a bit of variation in the powder charges you're dispensing. Taking the avg of several tells you your avg powder charge as opposed to weighing one and assuming the rest are going to be the same.

Even before I completely lost faith in my Lyman digital scale, I strongly suspected it read low at the low end. With a good scale, that shouldn't be an issue though.

[Les Snyder]

if you don't have a set of calibration masses, try factory bullets ... use a selection... as already said the larger the sample the better

a friend placed his powder scale on the styrofoam box it came in, and static charge really messed with the pan... it really varied due to relative humidity

[G-ManBart]

Most scales only weigh to .1gr, so you might think you're at 5.0gr, when you're really at 4.96gr or 5.04gr. That's enough difference to see on the chronograph (in most situations). If you average ten charges, you'll be able to see 49.6 versus 50.4 pretty easily. R,