Hallo Ping!
I don't have any information right now, but I'll meet my friend tomorrow (he's the bronze melter
) and I'll ask him!
Generally, lesser lead gives a stronger alloy, altough harder to melt. Alloys during Italian Medium and Recent Bronze Age (1500 - 1100 b.C) did not contain more than 10% of tin, and hardly 1, 2% of lead.
This was different from tool to tool (a fibula had more lead than an axe, for example), plus they used to melt destroyed or ancient objects, so that the alloy percentages were often uncertain.
A working tool or a weapon had to be stronger than a decoration; I believe that they obtained this also by heathing and hammering its edge.
By the way, the arrowheads we melted have never been used, so I can't tell if the percentages were correct. Anyway, these were 94% copper - 6% tin, and no lead at all. Arrowheads were flat, with a central rib, and were melted in series of 4. I could post pictures, shall I found them!
Greetings,
Mauro.