Just got a couple new molds from arsenal molds, both Keith design, one for .44, one for .357. My plan for these was to cast for 44 mag and 357 mag, so I'm aiming for Linotype hardness. My lead mix is range scrap (usual BHN around 12)mixed with Foundry alloy from rotometals (64.5%-lead, 23% Antimony, 12.5%-tin). I added two small tin pellets to get better fill out. My first batch I tested with the Lee hardness tester the following day, and it came out 20.9, which I was pleased with. I alternated casting molds from the same pot. Everything was air dropped. Odd thing to me was the boolits were dropping bigger than anything I've ever cast with my Lee molds. The 430 mold dropped at a very consistent 436. The 358 mold was dropping 360 boolits.
I know differing alloys can drop bigger or smaller depending on antimony content, etc., but this seemed excessively large. I can use them by sizing them down, but any thoughts for future casting on alloy composition or ideas for reducing the cast size without losing the hardness I want for magnum loads?
Thanks in advance for any ideas.