Swiss powder granulation WEIGHTS per same volume?

[Kevin Tinny]

Hello:

Stumbled into a puzzle trying to develop and compare Smith carbine powder loads.

First, please let me say that I am confused by the following:

My repeated WEIGHING of IDENTICAL VOLUME measured amounts of Swiss US 2F and 3F granulations indicates that the coarser grained US 2F (Swiss No. 3) weighs MORE, PER IDENTICAL VOLUME than Swiss US 3F (Swiss No. 2).

I would have thought the greater density of the smaller grains in 3F would have caused the same volume to weight more.

What am I missing in this, please? Thanks.

Kevin Tinny

[gemmer]

I also found that to be the case. No pun intended.

[Kevin Tinny]

Thanks, Gemmer:

Interestingly, the data sheet for the Lee Dipper Pack shows Cubic Centimeter weights per same volume to be the opposite. Maybe those are related to other traditional black powders.

So I guess that we know the "what", but not the "why, as it involves SWISS.

Regards,
Kevin Tinny

[John Bly]

I found the same thing some years ago with 3F Swiss and 1 1/2F Swiss. I never figured out why. That was probably 7 or 8 years ago. What is available now may be different.

[Kevin Tinny]

Thanks, John:

Will try to find out why from The Duke.
Will signal in Jan about a visit.

All the best,
Kevin

[Kevin Tinny]

Hello:

Info from the grey beard black powder cartridge shooters is that the DENSITY of a batch of ANY Swiss powder GRANULATION can vary up to 4%, BUT it will be VERY close on potency for the same volume.

They meter by volume and adjust for lot-to-lot variations, but that adjustment, if any is small.

American black powder, even DuPont and later GOEX, had a military strength tolerance of up to a total of 7%. Sifting out the "fines" in most American black powder will reduce the Extreme Velocity Spread by as much as 50%! This is not necessary for Swiss.

So the .7gr weight VOLUME difference between Swiss 2F and Swiss 3F is roughly 1.5% and well within tolerances. It can happen that one batch of 2F is on one end of the density tolerance and the 3F is on the other end for an overlap.

My tests just indicated an overlap within tolerance for a mechanically compounded mixture.

One other thing they shared was that generally Swiss 2F is approximately the same strength as GOEX 3F.

Regards,
Kevin Tinny