If it turns out to be Beryllium copper, I can tell you it is closer to brass than it is copper. I don't do it right now, but I used to restore historic golf clubs, specifically putters. I have worked quit a bit with Beryllium copper with regards to golf putters and it is way harder than copper, makes a great putter, but not to sure how it would work as a bopper. One way to tell for sure though, hit some rock with it an see what happens.