I have several powder horns but the main one I use for flintlock is one made by Scott Sibley. These are my powder flasks:
1. My first flask, an Italian knock off purchased in 1969. I removed the dark finish on it at the time and buffed it to a bright copper shine which has aged well over the last 53 years. I still use this flask for most of my revolver shooting and have a number of various size spouts for it. I keep it full of FFFg black powder.
2 A Dixon & Sons flask made in 1971 for the very first 2nd Generation Colt Navy revolvers with "COLTS PATENT" and "Dixon & Sons" stamped on it.
3. Another Dixon & Sons flask made in the 1970s, with "COLTS PATENT" stamp, but not sold with the 2nd Gen Colts.
4. An Italian copy of a Navy Stand of Colors flask with "COLTS PATENT" stamp, Not sure of the date, I think I obtained it in the 1980s. I'll bet Colt threatened to sue if they didn't remove the "COLTS."
5. A very shiny flask made in the 1990s. Looks like it may have originally been made by whoever made the Signature Series Colt flasks as the "PATENT" stamp remains but the "COLT" above it is covered by a rectangular block.
6. A Cabela's modern version of the Colt flask I bought for using Triple 7 with my Rugers.
7. A silver colored Remington style .36 flask I obtained in the 1980s.
8. A very nice modern Remington flask that I purchased from DD4lifeusmc several years ago. I use it with my Pietta '58 Shooters Model.