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Joined: 21 May 2015 Posts: 128

Is there any comparison chart of the relative bulk densities of various powders?

Joined: 26 Apr 2010 Posts: 3177 Location: NCWa

Yes there is, but I can't think of where I saw it . I'll rummage around and may post it later today, or Skeettx will since he's more organized than I.

Guys -- Get out a powder bushing chart from one of the reloader manufacturers -- the MEC bushing chart comes to hand quickly in my shop, and you can get it on-line, too. Going through that you will be able to infer the relative densities of most of the shotshell powders you will encounter.

To calculate the absolute quantitative densities, if you actually need them, you will need to have one or more of the powders in question, a good scale, and a reloader, with powder bushings -- only a few bushings are necessary. First measure the dimensions of the bushing and calculate the volume of the "hole". Then throw a few charges with that bushing and weigh them -- then average them. You will likely find the reloader manufacturer's bushing chart is conservative - i.e. the busing will throw less than what is on the chart. Divide that average powder weight by the volume you calculated and you have the weight per volume -- the absolute weight density. This would be at our local gravity, of course - not that of the moon or Mars, etc. - but hey, we aren't shooting there. Do that for a few bushings and a few powders if you like, and then go back to the bushing chart and extrapolate the densities of other powders, based on the relative densities derived from the chart.

Question -- I suppose this is about load fit in a given hull. Why would you need to do any of the above when it can be seen from a powder bushing chart and available load recipes all the info needed to decide if a certain powder would make a load fit a little better.

Joined: 04 Mar 2019 Posts: 1837 Location: Central ND

I agree with Tony. Unless this is about something other than if a certain load will fit?

Powder bushing charts work. I have used them for this purpose myself.