This is a copy and paste from my Facebook Page from several years back.......it's still good information, and kinda explains why so many of us learned to love Goex and Swiss many years back.
It was written by Wayne Stormer, one of several recognized Subject Matter Experts in the field. Somewhere in my files I have a very similar article by Bill Knight (Mad Monk).
Years ago, when I was going through a phase of life know as BPCR, I communicated a bit with Bill, one would be hard pressed to find a more knowledgeable, more pleasant fella than Bill Knight, but the same thing can be said of Wayne Stormer.
Differences In Black Powder
There are two main types of black powder commonly run into by black powder shooters.
** 1-"F" called "blasting powder" these days, which is uncut, of
irrtegular shaped grains greatly more sensitive, very
hygroscopic and will clump requiring it to be rolled in its
containers to prevent such clumping. It is also has a greater
range of granulation sizing in the size assigned to it. This is
the common gun powder of our ancestors in most of the
18th Century.
** 2- "Fg" called "sporting powder" specifically made for our
sporting gun use due to its being cut polished for consistent
slow burning characteristics and consistent sizing with
smooth pouring characteristics. This is the recommended
powder to be used, and DuPont/Goex has set the American
standard for such since 1802.
[It comes from the demand for the quality black powder that
was had by many German and Swiss back in the 18th
Century and was being adopted/put into use for the various
military forces.]
The sporting black powder made by DuPont had to do with the two advances in production. Those advances being the cut polishing of the grains with graphite, and the new use of the American standardized brass/bronze screening sieves that replaced the old reed and silk sieves. Not every black powder manufacturer complied with the standard screen sizing, but this was the standard set and what all else was compared to.
Cut polishing is tumbling the black powder over a set time with graphite powder. This both cuts and polishes the grains of powder. The grains are then rounder and of a more consistent size when screening. This is what give a greater resistance to it being hygroscopic, and it allows it to flow when pouring without clumping like the blasting powder does. These things provide a greater consistency when shooting our firelocks.
It is noted that Goex's sporting powder is an excellent standard black powder. However, it is dirtier than the Swiss sporting black powder. Why? Because Goex only cut polishes its sporting powder for about 30 minutes which will leave a minute amount of graphite dust with Goex's sporting black powder. That grayish-green color you see and mistake for fouling when cleaning is actually the reaction of the graphite dust to your gun barrel bore.
The Swiss sporting powder is cut polished four to five times the length of time Goex powder is. This results in a superior sporting powder the is highly polished without graphite remaining and attaching to the powder. It therefore has a glossy black polished look to it with superior performance. This is not to say that Goex is a bad powder in any way, but it does explain the difference.
One more thing to go along with this bit of information is that Swiss sporting black powder is made with adler buckthorn charcoal whereas the Goex standard sporting powders are made with a willow charcoal. The adler buckthorn is denser and thus produces greater energy output by about 20% with the comparative Goex powder. The Europeans do not use the same sieving sizes as we do either, so one must be mindful of the differences in their respective granulation sizes listed.
An example is:
100 gr by volume Swiss 1.5Fg = 125 gr by volume Goex FFg
70 gr by volume Swiss 1.5Fg = 87.5 gr by volume Goex FFg
50 gr by volume Swiss 2Fg = 62.5 gr by volume Goex FFFg
Note that Goex also markets a very nice Olde Eynsford sporting powder made with adler buckthorn charcoal or a mixture of adler buckthorn & pacific willow charcoal. Its volume measure must likewise take into consider the variation of the density of powder in comparison to Goex's standard sporting powder though being the exact same granulation size
.
70 gr volume Goex Olde Eysnford FFg = 87.5 gr Goex FFg
So, be aware of what you're dealing with and the proper volume amounts to be factored in and used in whatever you choose. If you are a re-enactor using the blasting powder for your re-enacting, be aware that the powder you're using can be a varied granulation smorgasbord of granulation sizes when used, and even including priming powder dust in it as you get lower in the can of it. That can produce much greater pressures in a barrel with a blank cartridge down the bore than a patched ball with a sporting powder load behind it.
Now there is the standard German Schuetzen Wano black powder, and the powders made by Schuetzen and Goex for Graf & Sons etc. Do your homework. For myself, standard Goex works just fine price wise, but if I'm going to be competing I'd go with the Swiss. Why does the Swiss cost so much more? Because only a limited amount of it is made and sold.