Smokeless and aluminum

[Kosh75287]

Propellants exposed to metal(oid)s like aluminum can decompose at much faster rates than when stored in containers made of polymer or other materials. The metal acts as a "template" on which the propellant's organic molecules (nitroglycerine, nitrocellulose) can "sit" and be acted upon by elements in the aluminum alloy, or even surface contaminants accreted to the metal despite repeated rinsing.
I doubt that any propellant so stored would develop a fast chain reaction and get hot enough to do anything (don't leave it in the garage over the summer), but I'd darn sure expect the burn characteristics to be altered.
Best bet would be to find an empty propellant bottle still capable of sealing and store it in there. Make sure you relabel it in an obvious way, also.


ADDENDUM: I'D be willing to bet that the old-style metal cans in which smokeless propellants were once sold, were also pre-coated on the inside with some sort of "rock-stable" polymer/sealant to separate new powder from bare metal.

[MT Gianni]

During the Hillary component scare of 93, a friend ordered a 33 lb keg of powder. I bought 8 lbs that I kept in the way it was delivered. That was two cleaned and dried 2 liter soda bottles. No chronograph changes in loads from that powder in the 15 years I had it. If my basement had caught fire the soda bottles would not contain pressure so they were safe. I can't say that about a canteen.

[Texas by God]

Propellants exposed to metal(oid)s like aluminum can decompose at much faster rates than when stored in containers made of polymer or other materials. The metal acts as a "template" on which the propellant's organic molecules (nitroglycerine, nitrocellulose) can "sit" and be acted upon by elements in the aluminum alloy, or even surface contaminants accreted to the metal despite repeated rinsing.
I doubt that any propellant so stored would develop a fast chain reaction and get hot enough to do anything (don't leave it in the garage over the summer), but I'd darn sure expect the burn characteristics to be altered.
Best bet would be to find an empty propellant bottle still capable of sealing and store it in there. Make sure you relabel it in an obvious way, also.


ADDENDUM: I'D be willing to bet that the old-style metal cans in which smokeless propellants were once sold, were also pre-coated on the inside with some sort of "rock-stable" polymer/sealant to separate new powder from bare metal.

Thank you, that was what I was wondering.

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[wv109323]

An old wife's tale is that Bullseye powder would eat a hole in the side of the Star aluminum powder hopper if left in for long periods of time.
The older metal powder cans had a folded seam down the side that would open under low pressure. They were not solid rigid containers. After metal containers there was paper and now plastic.

[indian joe]

Cleaning out my Dads stuff after he passed (powder would be 20 years old +)
All trap components
Red dot in cardboard - good as the day they made it
Winchester trap powder in metal can - good as the red dot
But in the same cleanup and from the same era was a can of powder completely degraded and the metal can turned almost to dust (cant remember what brand but there obviously some formulations that hold in storage and some that dont or didnt) .
I had IMI ball powder start the same process in the 1960's alongside some nobels powder that was ok. - The IMI powder changed colour and failed to burn properly

[Mal Paso]

And how do we know this? Internet opinion? Sure, they are thin, but still steel, and would likely rupture before building any meaningful pressure. But is this by some big design criteria?

The steel powder tins that I've seen have press fit lids that would pop out under pressure. I doubt there was a liner like the plastic coating in modern cans.

[NEKVT]

I once long ago shot a pound can of BP with a 6mmRem at about 250yds. The steel can with screw on cap was the same the Dupont/IMR smokeless came in back then. There was a big orange flash, a CABOOM!!!, and a huge white cloud filled the gravel pit. I found the can nearby split down the seam. BP being an explosive went off at the impact. A can of smokeless would not explode but burst and burn if in a fire. I have a Palco aluminum canteen from the '70s and although the OP was more concerned with deterioration that canteen is seamless and that along with the solid plastic cap that acts as a plug in a 1" opening would likely hold a lot more pressure before letting go compared to the steel can with seam and a thin screw on cap.