I was at the range a couple days ago and when I got there the ground was covered with these 380 cases that almost have a burnt black color to them. Since there seemed to be about 300 of them I decided to pick them up just in case they were brass. I did take some sandpaper to one of them and it looks like it may be brass under the coating but not sure. I took a magnet to them and they are not steel and they feel heavier than aluminum. Here's a couple pics one of the head stamp and one of the case itself. I've never seen this head stamp before but what do I know.



