When powder goes bad

[fatelk]

A couple years ago I had some 4895 surplus powder that went bad. I bought it years before from the son of an old timer who had passed away. It had been stored in an attic.

I noticed a brown gas in the glass jar it had been stored in, and it smelled real bad. I threw it out, but had another can from the same lot that I thought was OK so I kept it and used it.

I recently dug out a couple hundred rounds of .308 I had loaded with it. About 20% of them had split necks with nasty green stuff growing out of them. The brass was perfect with no splits when I loaded them a year or two ago. The powder inside was clumpy, corroded, smelly stuff. The other 80% or so is in various stages of decomposition. Even the bullets are corroded on the bases. I guess that's what I get for trying to salvage questionable powder.

The funny thing is, I bought a bunch of H4831 surplus from the same guy, stored the same, that is perfectly fine. It chronographs the same as the new stuff, and still shoots great. It's like something in the 4895 just turned to acid, but the 4831 wasn't affected.

 

[Slamfire]

I finished this week pulling the last of my match bullets from over 1000 rounds of 308 I loaded with surplus 44895.

This stuff has deteriorated badly. The bullets have green rust on their bases, most of the case necks cracked. The powder does not have that acrid smell, but it is only a matter of time till it turns red.

Hot, temperature cycling will deteriorate powder. No doubt poor storage conditions hasten the deterioration, but this sort of breakdown is due to the conditions of manufacture, and the age. And it appears to be irreversible. It will simply get worse with time, as I found out with another lot of surplus 4895 that I had twenty years ago.

I have read that old battle ship cannon powder was stored under water until it was recycled. It is probable that water absorbed acid coming out of the powder and slowed the deterioration, but did not stop it. Also the water kept fires from occurring.

The funny darn thing, in good brass the powder shoots just great. Just you can’t leave it in good brass as it causes season cracking.