Originally Posted by RockyMtnMT
I don't know, but I've been told... That the mass production of bullets doesn't allow for the use of pure lead and copper. The alloy products are easier to work with. But the alloy products are more brittle. The only production bullets that I know of that utilize pure copper and pure lead are the Swift Scirrocco, and Hawk bullets. The Hawk bullets are not exactly mass production either.
I was at Sierra this past spring and they said their bullet jacket are made 95% copper/5% Zinc and they didn't give the mixture of alloy used for the lead cores. I think the most common is tin/antimony and the mixture of those two with lead make the cores harder. It was interesting watching them make lead core.