I found this unopened cannister of BH209 in the older 10oz size in my reloading room (climate controlled room in my house, not in a barn or shed). I stopped shooting muzzleloaders in 2019, so it's at least that old. Also included is a brass flask with 3 nozzles. The installed nozzle was trimmed to give me a proper charge with BH209 in my rifle, about 110gr if I recall correctly. That was handy for shooting at the range.

$60 for everything.