Help me identify these three.. the first two were labeled Bullseye ?? Shiny black flake,larger than 7625.. 2nd - smaller flake,shiny, half gold color- half black.. 3rd,black with a few brown and a yellow tag..
Even if you were able to post pics, identification would be IFFY at best, unless its an obvious powder like Red Dot, Green Dot, Blue Dot, ect. If you or someone else guesses wrong, your asking for trouble. Assuming you got the powder for free, i'd dump it and start fresh, your gun and everyones safety is not worth trying to save a few bucks.
I have a half full steel can of red dot thats been sitting in my basement since the 60's. A few years ago I checked it and the red dots are almost faded out. I suspect in another 10 years you would not be able to tell what kind of powder it would be. "When in doubt throw it out".
A hole drilled into a stump, a long fuse and a bit of epoxy could make an interesting load. A bag of fertilizer, some diesel fuel and 10 minutes on the Internet under the "how to make a bomb" section could cause a problem for both the stump and the stump remover.