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powder shelf life
kumate
Member Posts: 2,314 ✭✭✭
how long will powder last in a dry area once it is opened and then resealed tightly
Comments
I've also got some DuPont IMR powders from the same period in the cardboard boxes and it's still good.
I used some Unique the other day from the fifties. It was in the cardboard vertical tube and it shot fine.
I've also got some DuPont IMR powders from the same period in the cardboard boxes and it's still good.
Was it mine[:D] I have the same stuff. Cardboard tube of unique from the sixties though. It was left over from my dads gun store. Shot just fine. I loaded it my 41 magnum. Best damn powder there is in my humble opinion.
There will not be a definitive answer for your question because of the number of variable which can affect the powder.
Many of us can recount positive experiences with powders which have been stored for decades. But this is not a testament to that concept. Moisture and heat will affect powder adversely. Air will accelerate the deterioration of powder. Depriving the powder of those factors will lead to better preservation.
Best.
In the 70's I shot 1000's of rounds that laid on the ground out in the weather for years some looked to lots of years.
I kept some pulled 5010 powder in glass jar's just to watch. Open hot attic storage didn't take too long to start turning red. Cool and dry with a lid lasted many years. Mind you this was powder loaded in the 40's and laid out in the weather for years.
how long will powder last in a dry area once it is opened and then resealed tightly
Assuming the powder is kept cool and dry (that's key!), it should last for many decades.
I think everyone has the experience of shooting really old rounds that worked perfectly fine, including stuff that's 40 years, 50 years, or even older.
As already mentioned, if the powder looks good, retains its shape and color, and isn't releasing an off smell, its probably fine.
Note that bad powder probably isn't going to "blow up" a gun, but it can lead to inconsistent velocity (meaning poor accuracy) and reduced power.
The worst possible problem is inconsistent ignition. "Hang fires" where the primer goes off, but the bullet doesn't launch for several seconds can be really dangerous. If you're not going by the book and counting for several seconds after a dud before you open up the gun, a round could go off with action open or while opening. . .that's bad.
Worse, a true "squib" load where the bullet leaves the case but doesn't leave the barrel can cause an obstruction, and then the NEXT shot fired into a jammed bullet can be catastrophic, leading to a bulged barrel, a ruptured one, or worse.
Oh. . .the conventional wisdom is NOT to put powder in the gunsafe, because in the event of a fire, the burning powder can turn your safe into a bomb. If you want to keep the stuff locked up, an ordinary wood, plastic, or thin metal cabinet is a MUCH better idea.