Ray,
The boxes were stacked so the cases were laying on their sides.

Bob,
I threw the cases away. I didn't try to dissolve any of the green, so can't answer your question as to water solubility.

Kingston,
The corrosion damage occurred from the inside out. I don't think the cases were exposed to any corrosive cleaners, especially not the inside of the cases.

Blacktailer,
I did find a box of 250 Savage cases loaded at the same time with the same lot of VV-140 powder. The pulled powder looked perfect. There was no corrosion in the case. They shot normally through the chronograph at the range.

Thanks, everybody, for your ideas.

Nifty-250

"If you don't know where you're going, you may wind up somewhere else".
Yogi Berra