Everything I can find, including the sheet which came with the Lee hardness tester says pure Lead has BHN of 5. Add .29 for each percentage point Tin. Add .92 for each percentage point Antimony.
The Lee instruction sheet specifically states "85% Lead, 10% Tin, 5% Antimony yields BHN of 12.5"
Which matches very well with any other sources I have read over the last ten years of casting.
Linotype is extremely rich in Antimony. A little increases BHN quickly.
I am curious how you had samples tested for Antimony content and cost for that procedure?
My ingots, after cooling overnight are testing at 12.4. After casting into bullets they will harden over time and powder coating will probably increase hardness as well. My guess is that bullets a year from now will test at 13.5 to 14 BHN. Which is exactly where my alloy has been that I have used since '14-'15.
With 450 to 500 lbs in this batch, I am sure the grandkids will be using it long after I am gone. Even if I make it to 90.
