What powders store the longest?

[js2013]

Anyone know what powders store the longest?
Besides storage environment, I'm wondering if single or double base, certain additives, burn rates, or ?? make a difference.
I've seen military powders last decades while others need to be recalled for going rancid.

 

[Jager]

Double-base powders - powders which include nitroglycerin - are less hygroscopic than single-base powders. The same is true of the various modern temp-stable powders, whose coatings produce a less porous, plasticized exterior around each grain of powder, than their single-base cousins.

It is tempting, then, to conclude that double-base and temp-stable powders last longer. But that is a leap that, as far as I know, has yet to be proven.

What is clear is that smokeless powders of all stripes, stored in those "cool, dry" conditions that all the manufacturers speak to, will last a very long time. And even when storage conditions are less than ideal - Bruce Hodgdon stored much of his post-WWII surplus powder in a couple of train boxcars; and powders have been sold in everything from plastic bottles to cardboard cans to metal canisters to paper bags - smokeless powders are remarkably resilient.

I personally have canisters in my powder closet dating back to the 1980's. And I've only ever pitched two cans of powder... a 35-year-old can of IMR-3031 a couple years ago because the top of the (old Dupont) metal can was corroding (the powder inside was fine, and I later regretted throwing it away); and a 15-year-old can of LilGun, pitched just last week, because it had begun to smell sour.

Notably, LilGun is a modern, double-base powder.

 

[Joe Maisto]

Double-base powders - powders which include nitroglycerin - are less hygroscopic than single-base powders. The same is true of the various modern temp-stable powders, whose coatings produce a less porous, plasticized exterior around each grain of powder, than their single-base cousins.

It is tempting, then, to conclude that double-base and temp-stable powders last longer. But that is a leap that, as far as I know, has yet to be proven.

What is clear is that smokeless powders of all stripes, stored in those "cool, dry" conditions that all the manufacturers speak to, will last a very long time. And even when storage conditions are less than ideal - Bruce Hodgdon stored much of his post-WWII surplus powder in a couple of train boxcars; and powders have been sold in everything from plastic bottles to cardboard cans to metal canisters to paper bags - smokeless powders are remarkably resilient.

I personally have canisters in my powder closet dating back to the 1980's. And I've only ever pitched two cans of powder... a 35-year-old can of IMR-3031 a couple years ago because the top of the (old Dupont) metal can was corroding (the powder inside was fine, and I later regretted throwing it away); and a 15-year-old can of LilGun, pitched just last week, because it had begun to smell sour.

Notably, LilGun is a modern, double-base powder.

And I as well... have some RL-11 from the late 60's...early 70's that I used in my Whelen, in the square tin cans. It looked and smelled as good in 1999 as it did back then. I reluctantly... tried it at the Super Shoot with no ill consequences. All went well. "Lesters" daughter was in disbelief . Here it is...2021 and it still smells as it did back then. Quite amazing...