Aluminum casing

[230RN]

I found that old box of CCI Blazer I mentioned above and noticed that they're heavily headstamped, including an annular ring around the edges of the case rims. It's almost as if they wanted to give a lot of extra work-hardenig to the heads. Just a guess, but that's the first thing I thought of.

Terry, 230RN

REF:
https://www.gamemastersoutdoors.com/cci-blazer-ammo-357-magnum-158-grain-jhp-3542/