Most of the time we strive for pure lead so we can get them down the barrel without a hammer. In the case of this mould I could use wheel weights and they would still work. The 1000 yard ML shooters are using 20- 1 or 30-1 lead that is harder than some of what I am using. 45-70 shooters typically shoot even harder yet. In the grand scheme of things the lead I am using most guys would call pure. Since I have a hardness tester I can adjust the lead hardness to tweak load performance.
Ron