Home Forums Reloading Big Game Rifles Case Corrosion Mystery

I had an interesting discovery in a box of my old reloads recently. I posted this in another thread and didn't get any ideas so I will try it here.

This is a puzzle to me. I have a plastic storage container that has several boxes of 30-30 ammo, factory and reloads, that has always been stored indoors. I recently pulled out an old box of Federal ammo that had been once fired and reloaded back in 1999. I was going to shoot it up since it was one of the older boxes I had.

When I opened the box there was massive corrosion on many of the cases. As you can see, after I reloaded these cases I placed them back in the Federal factory plastic cartridge holders and put them back in the factory box.

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Here is the load:
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The slightest pressure on the side of the bullet snapped the case in two. There are fine cracks in the neck under those lines of corrosion. The powder appears normal.

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The strange thing, also, is that when I dumped out the powder, the entire inside of the case was covered in corrosion, from the head to the neck. It appeared that the cases had corroded from the inside out.


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This is what the base of the bullet looked like:

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I checked all of the other ammo that was in the plastic storage box, including some other reloads of the same age. This corroded lot was the only box of Federal cases. There was no corrosion present on any of the other ammo. Not even a speck. Other brands of cases loaded with the same load looked fine. The plastic cartridge holders didn't seem to be the cause.

I still have some of the same lot of R-P 150 gr. Core-Lokt bullets on my shelf, and they look fine.

As far as I know, these cases were not treated any differently when I reloaded them back in 1999. I don't tumble my cases or use any liquid cleaners. I don't understand how the corrosion started from the inside, if that is what happened. That is how it seems. The powder that I dumped out of the broken case looks perfectly normal.

Has anyone else had this sort of thing happen? Does anybody know what happened here? Is it just a bad lot of cases? Could it be some kind of reaction between the bullet matel and the brass? The worst of the corrosion is all around the base of the neck. This is a first for me in 50 years of reloading. Comments and suggestions are welcome.