Years ago in the mid 70's, I was given - or bought - a large red can marked American Deadshot Powder still containing about 3 or 4 pounds of very shiny, hard, angular black powder, granulation 2F. This was the best powder I'd ever used. Cleaner burning than the C&H, GOX, or Meteor powders then available. I was shooting a very much modified TC hawken stock, with a 38" twist Bauska barrel in .50 cal. I used the TC Maxiballs lubed with Crisco and turned out many 5 shot groups at 100 yards that ran !" and slightly less between centres - 100 yards range - open irons, of course. It was the cleanest powder and exceptionally accurate. I seem to remember that C&H's would do around 1 1/2", so the reduction by 50% and a bit more was amazing. I could actually see then and was shooting a lot of competition with metalics in 3-position shooting so shooting good groups was not foreign to me. That was the powder and load I used for the Turkey shoots, limit 2 turkeys. That rifle and load won me the 3rd and 4th turkeys at the annual shoot every year. The 1st and 2nd always went to Bob Cheney (no relation) who was an opympic shooter at the time. Bob used his very specialized offhand olympic rifle. The other shooters were the nromal 3-po and prone shooters I was competing with at the time. Everyone shot their match rifles, 'cept me and one year, Taylor, who used his .62 Hawken. That year, Taylor won the 5th and 6th turkeys - no small feat as he was shooting C&H powder. He really upset one German shooter who was used to wining the 5th and 6th. All shooting was at 100 yards, offhand.
That American Deadshot powder was very clean burning as noted above and seemingly moist burning too, as noted by Ned Roberts in his big book. I did a brief check then, and read that the American Deadshot powder factory blew sky-high or ceased production in 1898 or around then. The old powders were certainly superior to what we buy today. Apparently Swiss is similar to some of them, except for the 'moist' burn.