The "best powder measure" thread got me to thinking and reading some previous posts and it brought up (to me) the question of how important is weight repeatability. I am just going by others opinions here and was wondering if anyone has seen or done an actual study of the weight vs. volume effecton accuracy?

interesting...

weight is density of material , in one gravity and STP, expressed in a set of terms of a mass

volume is the displacement of a mass of material, in one atmosphere, at stp,

both measurements of physical properties have MASS, Volume, Density....

if 1 cc of water, at stp in 1 gravity, weighs 1gram (it does) then the choice of measuring it in mass terms or volumetric terms, is abritrary.


I think your actual question is which is more repeatable, rather than which is better. If you have 100 grains of powder, it will displace X volume... and X volume will weigh 100 grains.

the trick is, in both, to have an accurate way to reproduce results. Since powder throwers DO introduce error, it is up to the individual to choose between THAT level of accuracy vs the inherent error built into a balance scale and its use.

Since electronic powder throwers have an even GREATER error (rounding) than balance scales, that is functionally thrown out the window. It is POSSIBLE to have a VERY VERY accurate electronic scale... and it both costs high $$$ and is VERY sensitive to dust and environment.

Myself, I have experienced ZERO change in accuracy or stand deviation if I weigh the loads or throw them... I do check every 5th or 10 thrown charge for weight.

So, in my opinion, throwing beats weighing, but one should always check the other measurement. AFter all, who weighs loads and then does not do a check for even volumes on the loading block.

the ammo making companies THROW charges.....


jeffe

density is the mass of a volume

As far as accuracy goes, case concentricity and bullet seating depth has more effect than small variances in powder weight.