Powder Shelve life

[alwie]

All,

What is the shelve life of a powder open and unopened?  I read that VihtaVouri is 10 years sealed.

[grayfox]

I'm not sure there is a complete formula, it depends on how it's being stored, temperature, humidity etc.
I saw a writeup on the web however, that had a graph of expected life vs temperature... I think. Not too long ago.
Maybe do some google-foo?
One thing I also remember, if it has a rancid or strong smell it's gone bad. Something like that.
At proper temperatures you could be looking at 10 years or more, but that's strictly from memory.

[CZ527 Guy]

This may shed some light on your question.

https://www.rifleshootermag.com/editoria...y%20weaken.

[Old Bob]

I have two old cans of powder. One is IMR 4198 & the other is Alliant Reloader 7. The RL-7 still has a faint acetone smell to it but the 4198 will curl your nose hairs. They are both the same approximate age (20 years old) & have been sitting next to each other in the powder drawer of a steel filing cabinet in an air-conditioned room. There is also some brown dust in the 4198. It could be rust but I'm not sure 'cause the inside of the can still has a shiny steel color. It's probably from the chemical break-down of the powder. Will probably spade it into the soil of my rose bush.

I've got some Lapua 220 Russian brass loaded with that RL-7 for fire-forming into 6mm ARC.

[Old Marine]

I have never read about powder shelf-life limits. I have powders that are over 40 years old and are still functioning like new. My load room is kept cool and very dry and that is optimum for keeping powder. I also make sure the can lids are on tight.

[r.tenorio671]

...my preference is to "attempt" to buy powder by the 10 can case so that I can only break the seal on a 1 pounder at a time. Typically the lot numbers of the 1 pounders will match as well. It may cost marginally more than a 8 pounder jug, but in the long run I feel it benefits me, seeing as how I live in a very high humidity locale, YMMV.

[alwie]

...my preference is to "attempt" to buy powder by the 10 can case so that I can only break the seal on a 1 pounder at a time.  Typically the lot numbers of the 1 pounders will match as well.  It may cost marginally more than a 8 pounder jug, but in the long run I feel it benefits me, seeing as how I live in a very high humidity locale, YMMV.

That was my thinking too.

[r.tenorio671]

...my preference is to "attempt" to buy powder by the 10 can case so that I can only break the seal on a 1 pounder at a time.  Typically the lot numbers of the 1 pounders will match as well.  It may cost marginally more than a 8 pounder jug, but in the long run I feel it benefits me, seeing as how I live in a very high humidity locale, YMMV.

That was my thinking too.

...unfortunately, due my location I am pretty much limited to online purchases.  When I started to gather components for my 6ARC project I took whatever I could get as soon as it became available during this current supply constraint....

...since my 1st outing with Lever showed just how "dirty" it is, I look forward to what other manufacturers come up with as they begin developing 6ARC related products. My biggest concern are the reports I've seen of folks finding out their gas tubes becoming clogged.  That was a shocker.

[alwie]

For me a clean powder is important for keeping my AR cleaner longer. I also run a gas piston system which helps.