Coloring brass???

[divingin]

I found some Winchester law enforcement .223 training ammo that had
a purple coating. I rough sanded a piece and it shows the brass that was
then plated, then the coating. Something I would not run in my chamber ??

That stuff is just a purple paint/dye applied to designate it as non-duty ammo. I put a couple of pieces into a pocket for my collection (I pick up odd brass); it was normal brass-colored when I got home.