I have been casting bullets for my 45/70 using new roofing lead (sold as 99% pure lead). the hardness being below the value registered as 'hard cast' 15.4BNH on my hardness tester,
I decided to try and increase the hardness following the advice on the literature enclosed with my Lee Lead Melter i.e. add tin 10% and antimony 5% to increase hardness to BNH 16.0
The Lee Pot stated a maximum temp attainable is 483 C and antimony melting point is 630 C . Looking at various posts by casters attempting this process, it seems that the best way of achieving mixing of lead / antimony is to melt the antimony separately and then pour the liquid antimony in the molten lead and stir.
The resulting mixture poured into my Accurate Mould successfully but oddly the sprue plate required only very light gloved pressure to swing clear revealing a fully filled square based bullet. As the bullets fell from the mould they had the usual shiny finish but within 30 seconds or so they acquired a matt grey finish,
Another result of the modified lead mix was that the bullets weighed around 15 g lighter than the pure lead rounds.
In spite of fluxing with beeswax the process produced a huge quantity of light brown dross with a sandy texture.
It remains to be seen how they shoot compared with the pure lead.
Any comments/observation from members would be appreciated
I decided to try and increase the hardness following the advice on the literature enclosed with my Lee Lead Melter i.e. add tin 10% and antimony 5% to increase hardness to BNH 16.0
The Lee Pot stated a maximum temp attainable is 483 C and antimony melting point is 630 C . Looking at various posts by casters attempting this process, it seems that the best way of achieving mixing of lead / antimony is to melt the antimony separately and then pour the liquid antimony in the molten lead and stir.
The resulting mixture poured into my Accurate Mould successfully but oddly the sprue plate required only very light gloved pressure to swing clear revealing a fully filled square based bullet. As the bullets fell from the mould they had the usual shiny finish but within 30 seconds or so they acquired a matt grey finish,
Another result of the modified lead mix was that the bullets weighed around 15 g lighter than the pure lead rounds.
In spite of fluxing with beeswax the process produced a huge quantity of light brown dross with a sandy texture.
It remains to be seen how they shoot compared with the pure lead.
Any comments/observation from members would be appreciated