I need a Favor: Black Powder - WEIGHT in grains v. volume

[AreWeNotMen?]

Yes, I know using volumetric grains (is that even defined?) is what has "always" been used, but since mine will not arrive for another week or so...and because I come from a long history of reloading smokeless powder, I would like some real world, hands-on information/data (NOT some "formula" found on the web). My request may "go against the grain", or seem downright blasphemous, but if someone can help out, I'd appreciate it.

Here's my request - IF you have Pyrodex P and/or Goex FFFg (new manufacture if possible...not sure if it differs from older lots) powder, and you have an accurate powder scale, would you please use your traditional volumetric powder measure to dump 15g, 20g, and 25g volumes respectively of Pyrodex P and/or Goex FFFg onto your scale and let me know the weights of each in grains? So if you have both powders, I'm looking for six data points.

Thank you!

[ar15barrels]

I am not going to weigh the small charges you are asking for 6 times, but I have some older Goex FFFg and Pyrodex P.
I set my volumetric measure to 120gr and got the following actual weights:
Goex FFFg 124.3grains
Pyrodex P 88.8grains
From those actual measurements, you can back calculate what you want.

You can realistically use FFFg direct weight and you will be 3.5% underloaded compared to volumetric measure.
This difference is because FFFg packs closer together than the larger powders that the volumetric measures are calibrated to.

Volume to actual weight for Pyrodex P calculates at 74% with my numbers so 20gr volumetric of Pyrodex P will weigh 14.8gr on your grain scale.
Now that these numbers are posted on the web, you can ignore them and wait for your actual volumetric measure to arrive and just use it instead.

[AreWeNotMen?]

That's helpful...I can do math.

[Sandspider500]

Huh, if you measure 15, 20, or 25gr of 3fg in a volumetric measure and then weigh it,..... It will weigh 15 20, or 25gr, or very close to it.

If you use Lee dippers and 3fg a 1cc=15.9gr 1.3cc=20.7gr and a 1.6cc=25.5gr or close enough.

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[Sandspider500]

Pyrodex p with those same dippers 1cc=12.1gr 1.3cc=15.8gr 1.6cc=19.4gr

[ar15barrels]

Huh, if you measure 15, 20, or 25gr of 3fg in a volumetric measure and then weigh it,..... It will weigh 15 20, or 25gr, or very close to it.

I believe that volumetric grain measures are based on Fg black powder granules.
Finer granule powders will throw heavier charges in volumetric measures because there is less air space between the granules as the granules get smaller.

As you can see from my actual measurements posted above, a 120gr volumetric charge actually weighed 124.3gr which is 3.5% heavier than expected and that's because of the finer granule size.

[Sandspider500]

I'd say that's well within the fudge factor for lot to lot difference's of goex fffg. If you broke that up it would have measured 15.6gr if you had set it to 15gr. Goex fffg has a similar volume to weight of water, which your measure maybe calibrated to. 1g of h20=1cc h20=15.432gr of H20.

[Sandspider500]

alright a

[AreWeNotMen?]

Thank all - this was helpful. Again...I was struggling with the "being close enough" concept with black powder. Coincidentally, I received my volumetric measure yesterday.