The VERY best powder I every shot, was American Deadshot Rifle(I think). It was in a 10 pound can, about 1/2 full when I got it. The powder was very angular, sharp, shiny, hard granuals.
I poured the powder off and re-canned it in C&H or Meteor cans, iirc. I had to use a sieve as there were chunks of rust in it, from the inside of the powder barrel. Sieving it, got most of it out
but says it got wet at one time or another. There was no deterioration of the powder and good stuff, it was.
A. Deadshot, I read, was the second best powder in the world, second only to C&H #6. That said, perhaps Swiss is as good, I don't know. There was less cleanup needed with it, so I guess maybe
it was shooting more cleanly than the 1975-era GOEX, Meteor and C&H. I did manage to score a couple cans of Dupont 2F but it seemed no better than GOEX.
That powder had to pre-date 1898 as seems to me, the 'plant' blew up on that date. There was no powder on the market that looked anywhere close it so I am sure it was the real deal.