ORIGINAL: sabotloader
jaybez101099
They are/will seal tight. The only negative that I can think of with them, as a powder storage, is that they are clear. Powder comes in dark cotainers for a reason... powder does not like light. How long it takes for light, UV's, to work on powder I do not know. I use the tubes for a day @ the range, but I still use the 4-in-1 speed loaders for hunting.
I use a smaller, but otherwise very similar, version of these vials to hold pre-weighed smokeless loads both when I go to the range and for hunting. I got mine from Randy Wakeman. They aren't big enough to hold a full charge of BP or subs though. Mine hold my usual 44 grain charge of AA5744 and are about 2/3 full. I like them because I can weight and throw the powder from my RCBS powder measure into the vials, and they are the perfect size for loading the rifle.
As for being clear and the issue of UV light. I don't know about anyone else, but I keep my powder vials, bullets and primers in a possibles bag (actually, it's a large camo fanny pack), so the powder is only exposed to sunlight when it's being loaded into the rifle. The vial do a great job keeping powder fresh and dry. I had 4 vials I found in my gun case that had been filled from two years ago with 44 grains of AA-5744. Out of curiousity, after examining the powder to rule out obvious deteriation, I loaded and shot that powder and put the bullets into the same group as the vials I had filled that morning. That's proof enough for me.
Mike