Federal Caseshot Matrix

[alwion]

when I had the choice to buy a couple, I thought the dark one was pine pitch, was kinda sticky and more like amber. the sulfer one I did get I just looked at, and I would swear it looks like yellow spray foam, which could be "modeled"

[alwion]

https://www.offgridweb.com/survival/how-to-make-pine-resin-glue-sticks/   this is for making a hardening black pine resin, used 100's of years ago. might have been it, as it would have been easy to make

[CarlS]

Quite interesting and sure looks very much like it.  I don't recall it having that pine tar smell.  In some cases it is still soft inside the shell so one would think it would still have that pine tar smell.  I had always thought it was a compound of this:
  https://en.wikipedia.org/wiki/Asphalt
known at the time as asphaltum but I don't know.