Powder storage

A warning about powder storage
I had this empty can in a box with other cans of the same era. It was next to a full can and had probably been for a perhaps a year?
Well the full can went bad and ate this can and a couple of others near to them.

What (chemically) caused that? Humidity?

Stored in sunny, but very dry, AZ so not humidity.
My best guess is the acid not being completely removed/washed away when the powder was manufactured and when braking down eating the cans.
Lost a nice green labeled Gallery Powder can.
What causes the powder to break down? I don’t know, perhaps just age? After all, nothing is forever.

Sorry to hear about the loss of your powder cans.
Heat is an enemy of smokeless powder and will cause it to degrade.

Hodgdon Powder Company instructs users to store smokeless powder in a
"Cool, Dry Place". I have some L&R “Sharpshooter” smokeless that was made in the late 1890’s and it is still doing well.


This is like the breakdown of steel-cased German ammunition. Nobody wants to do what is necessary to preserve these - take the powder out through a hole in the side of the case, so the crimp isn’t disturbed. Everyone considers such a round “ruined” which is silly, and as a result worthless - the end result will be thousands and thousands of specimens totally destroyed, including many rare ones.

If I had beautiful powder cans, sealed full, I would open them and dump the powder. If you can’t see the powder because it is in a sealed can, what have you learned from having the can - absolutely nothing that is not on the label. Better the can be empty and preserved for the information on it, as well as the beauty of some of the cans and labels.

Just my opinion - I know it goes over like a lead balloon with most cartridge accumulators. Without a consensus on value, of course, no one wants to do it and lose their investment. That I can understand. Someday, though, when laws prohibit cans of gunpowder and loaded ammo, or so many specimens have been ruined, maybe it will happen.

John Moss

I think if such items as steel powder cans or steel cased cartridges are stored in airtight spaces with oxygen-absorber packets (not just desiccant packets), the oxygen will be absent and no reaction can take place. At least this is what I have thought, unless moisture gets to the steel and there is oxidization from rust? Am I right? I keep all of my ammo in the basement in steel ammo cans with good rubber gaskets, and then those ammo cans in a huge steel-plated wooden trunk and vault which are sealed, have moisture absorbers and have weatherstripping on the doors. I haven’t gone so far as to use oxygen absorbers with ammo storage, but I don’t really have any collectible steel-cased ammo that is worth anything.


The sad thing is that the “evil comes from within”. The discussion on “green slime” started a while back involved a post WWII US manufactured cartridge stored in the very dry state of Arizona. This can the same. To some extent, everything is decomposing at some rate and it seems that smokeless powder may be prone to accelerated breakdown all on its own. As mentioned in the earlier post, nitric acid is produced by this decomposition and that is just plain nasty stuff. Other factors are probably manufacturing quality and the use of stabilizers to deter decomposition but I would bet that no ammunition manufacturer, past or present, is designing their product to last 100 years. This may really come into play with wartime products made to be used within a year or two. Primers can get ugly too.

John may not be winning any popularity prize with his comments (we just about all desire maximum originality of our collectibles), but the sad fact of the matter is that the self-destruction of our prized collections may be inevitable and that perfect looking gem you looked at today may break your heart tomorrow. Refining the process of removing the powder could ease some of the pain as in a very tiny hole and a solution injected, powder “melts” after a while, solution removed, rinse and dry? (Thinking of Ron M’s suggestion on the grenade cartridge gone bad but would have to be done before deterioration).


Going to the extreme for ammo & gun storage:

The vault which I had mentioned above:

I built it about 4 years ago. It is about 7ft tall, 4ft wide, and 4ft deep. It is 2x4 wood for the frame with 3/8" particle board panels all around. The base is actually 1/2 inch off of the ground on stainless steel bolts built into the frame which act like stilts to keep the base dry in case of basement water. I used stainless steel wood-screws everywhere as well as liquid-nails adhesive on all the wood-to-wood surfaces for extra strength. Steel corner-brackets were used in most all corners of the frame to keep everything square and strong. After all the wood had set up with the liquid-nails I sealed all of the seams with Geocel sealant, and then painted two coats of oil-based paint on all of the interior and exterior surfaces. The doors swing out on 3 heavy-duty tamper-proof hinges each, and the upper & lower padlock mounts are huge steel eye-bolts - 1 on each door opposite & offset from each other and one in the central front vertical spine so that all 3 bolts sandwich together tight for a padlock to go through vertically. When the locks are in, the positioning is such that bolt cutters & saws cannot have access. The central padlock mount is a surface-mount tamper-proof lock. The outer skin is carriage-bolted plate steel which actually has an all-over layer of steel wool between it and the underlying wood so as to foil any drilling attempt (it binds-up drill bits causing the drill to kick back). Shelves inside are set up for cases, guns, magazines, and both bottom sides are sized just such that a certain layout of ammo cans will fit snug in a couple different layouts and height possibilities. There is a 900 gram rechargeable desiccant box in the center to absorb any moisture which I recharge once a month by baking it. Weatherstripping is around the whole door, and tiny mini-desiccant packs are in each ammo can which I change once a year. It cost about $650 for everything to build it, and considering what the big steel vaults from Remington and the like cost, I consider this a great deal since it has allot more space, and is secure enough.

It’s a great thing to keep everything safe and dry, and hopefully safe from possible fire damage, but more importantly to hide away my extraneous and non-authorized expenditures from the boss here at home.

As far as the contents… The interior is very cool and worth showing, but for my sake as far as not having the BATF knock on my door, I’ll just leave that to everyone’s imagination.


Very impressive. Hope you never have to find out just how good it works!

Nothing holds back a growing collection like a curious wife…For me it’s never “What is that?” or “That looks interesting!”, it’s always “How much did that old thing cost?”



Smokeless powder provides it’s own oxygen (nitrates) in order to burn in an enclosed space so I’m not sure you’d gain anything with oxygen-absorber packets et al. The dragons are inside the can, not on the outside.


FYI powder is out of all my cans NOW
And it’s not all that hot. The cans were in my air conditioned office, but in a confined space next to another can containing a different powder. Think that might have had something to do with it.

Matt nice safe!
I understand Gypsum drywall board in two layers (overlapped seams) is what is commonly used as a fireproofing material in safes.