Good day

I had a chance to quickly look over a few old 10 guage shotshells, and they puzzled me with what appeared to be a seal over the crimp with what I'd best describe as a "clay-like" covering over the crimp. Anyone able to shed light on this?

DJ

Possibly it's water glass (sodium silicate). Your grandmother used it to preserve eggs as it sealed the eggshell. There's quite a few other compounds that could have been used back then too.

Bye
Jack