Not to interrupt, but I don't think the primers can be sorted by looking at the exterior. I've read that when federal loads some of the larger magnums that they use a primer slightly hotter than the 215, however I've seen no evidence of the change. I do recall Weatherby advertisements from the 60s that made a big deal that the loadings used Federal 215 primers- no indication that they were any different from "regular" F215s. It would be interesting to see what performance difference there is. I'll be getting some of these brass/primers and I have some F215s so when the snow clears and the government lets me out of the house I may be able to load some of each up and see how they fair over a chronograph.