If ya can scratch it with ya thumbnail it`s close to pure Pb 5-7 bhn
If ya can`t scratch it but can dent it with ya thumbnail it probably has some tin 8-11 bhn
If ya gotta work hard to dent it even on an edge with the thumbnail it probably has tin/antimony mix but not hi %s 11-15 or so
If it`s hard as woodpecker lips & ya broke ya thumbnail it has a hi content of tin/antimony 15-22 bhn & should be mixed 50/50 with pure , as the hardest of alloys is not needed for most handgun applications.
For 357/44 mag I shoot for 12 bhn with a bit over 3% tin to tuffen the bullet a bit so it does`nt shatter & it grabs the riflin better.
Of course this all depends how hard ya thumbnail is & if ya bite em or not
If ya care to send me a peice I`d be more than happy to test it with my Lee bhn tester though .
Wanted to add: I`d bet what you have is pure if it`s in sheet or slab form & I`ve seen muzzle loaders trade 2# for 1# pure to cast for the smoke poles !
