Powder Expiration?

[Ricochet]

Im thinking about getting into reloading with all the ammo shortages.
I was wondering if I bought powder in bulk and left it in its sealed containers, how long would it last and still be effective?

[cephas]

Depends on how well it's stored. There's a reason you won't find an expiration date on a can of powder. It'll last if stored properly. Not a big user of 296 but finished up a can of it this winter that was stored in the old cardboard container. At least a decade old or so. Also powder stored in milsurp ammo lasts awhile too.
From Alliant: http://www.alliantpowder.com/getting..._handling.aspx
Notice the part on storage and checking for deterioration of powder.

[Zeeba]

I got out of shooting/ reloading back in the middle '70s to pursue other endeavors. When my eldest son showed an interest in trap shooting in 2012, I found an old shell bag loaded up with 175 Remington RXP shells using Red Dot powder that sat in my basement since 1976. Every one of those shells fired, with no poofters, 36 years later.
If that Red Dot could fire in a less-than-perfect seal of a reloaded shotshell, I wouldn't worry about powder that's been in its original container.

[DucatiRon]

Cool and dry is all it needs.

I'm using powder my father had bought in bulk back in the mid 80's. Way back when he ordered a 45lb jug of Solo 1000. We used it for shotgun shells. About 2 years after he bought it we stopped shooting and reloading because life had gotten in the way. Fast forward to today and I'm still using the same jug of powder loading up my 10mm IDPA ammo.

Cool and dry baby. Cool and dry.

[Hawk]

I'll add keeping the powder out of the light. As in leaving it in a transparent powder hopper in a sun lit room. And of course protect it from any type of long term continuous vibration. As in the trunk of your car, next to a compressor or pump, etc.

[tl_3237]

Count me in as one of those that feel that powder shelf life is practically indefinite if store properly.

I'm still working on some 2400 that I bought in the 60's.

[Stooperzero]

I gave raxar some herco 2400 from the 70's , musta worked cuz he aint dead.

[JenniferG]

The cool and dry will keep powder for many years however, if your powder does begin to go bad it will have a nasty strong odor to it. Powder in usable and good condition has a generally pretty neutral and low odor. You will know if it starts to go bad and it begins to break down when you've been around fresh powder for a time there is a noticeable difference in odor. Other signs are stains on the cardboard containers making the container appear that has gotten wet. Rusty metal containers are another warning sign.

The man at my gun club that taught us some of his reloading skills showed us a container of Unique powder that had absorbed moisture and began breaking down because it was stored too close to a window that leaked when it rained. It has a very acrid strong smell similar to ammonia and you'll pull right away from it.

[GeneCC]

Im thinking about getting into reloading with all the ammo shortages.

I was wondering if I bought powder in bulk and left it in its sealed containers, how long would it last and still be effective?

As everyone else here has said, "Depends".

Nitrocellulose is chemically unstable. Over time it will form breakdown products. These products cause the rate of breakdown to increase.

Manufacturers add stabilizers to NC based powders to reduce the rate of breakdown. These grab the nitrogen oxides from the breakdown of the nitrocellulose. Puts the brakes on breakdown.

Powders respond to ambient temperature and water. The higher the ambient temperatures the faster the the natural degradation of the NC powder. Water causes problems because when it's cold water expands, breaking the grains. Smokeless powder surfaces are carefully engineered, along with a layer of "deterrent" which slows down initial deflagration. Break the grains and you get pressure excursions.

I am not sure if primers are sensitive to water too.


"Old" powder has a sour milk odor. In extreme cases it will start to change color.

I pulled World War II era 7.7 Arisaka ammo for the bullets. The grains were extruded, about half the length of IMR 3031 but marginally thicker. The powder had flecks of orange in it along with the sour milk odor. I would not have considered using it. Poured it into some Kleenex and burned it.

Fresh powder will have a solvent odor.

[Ricochet]

Thanks for all the replies.
Looks like I'll be able to keep powder for long term storage.