I’m sure most of you have seen this type of thing before. So, I’m just lamenting the loss and am reminded that we really don’t know what’s going on in those old sealed boxes. An old, sealed, 2-piece box is a treasure and, perhaps, it’s a good thing we can’t see what’s going on in there. The box (shown) these cartridges came from was not fully sealed. 10 of the 50 are a loss, the rest? My first clue was the exposed bullet cannelure on some rounds which led me to dump the box.
Only recourse to prevent total loss is to pull bullets and scrub the inards! I have done this in the past with Sharps cartridges, in order to preserve them, after losing a couple. At that time, I wiped the insides with a film of polyethylene oil and it seems to have worked. But that was over 30 years ago.
I have worked with artifacts of stone, wood, organic textiles, etc. (anthropology) but not specifically with brass & copper. I am hoping that with “better living through chemistry” there might be something new out there. A less messy, protective or “neutralizing” agent. I’m not sure if the (relatively) new rust inhibitor