Don't know about shelf life.. but I was once brought a Civil War Musket to look at. The story was it was used by an ancestor of the owners in the civil war. I checked the bbl and there was something in it. I started taking stuff out of the bbl. When I got done there were 7 full loads in the bbl. Minie ball and powder minie ball and powder etc etc. Don't know how old the powder was but it was at least 50 yrs old...and judging from the bullets etc I think it could have from the Civil war. I loaded a 65 gr charge(looked like 2F) in my TC Hawken...capped it and touched her off. It hit within the margin of error of my new black powder loads.with a 490 round ball. All that powder went off just fine. Still have the minie balls. BTW that gun had probably been used by 4 or 5 generations of kids as a toy. The nipple was peened over from being hit so many times... Just think if it had sparked enough to go off one of those times!!!
