Underwood "problem"

[Quick 2]

Looks a lot like powder tags to me. Back in the 80's IMR had tags in all their powders. I can remember that powder tags were going to become the norm until everyone started yelling it was put in to be able to trace which powder was used and that was what it was for to I.D. the powder but people thought it was to trace it back to a individual canister and see where and who bought it. But the actual use was to I.D. that it was IMR powder. With it not dissolving with bore cleaner is what makes me think its powder tags. I always used to brush everything off before using any solvents or cleaners. Back then there was not as many choices in powders as there is now.