I like to cast big batches of HP bullets so they all have the same expansion characteristics. Then I only have to jug test at a few velocities. I write down batch info, alloy notes and velocities of recovered bullets on a piece of paper. Put the paper and expanded bullets in a baggie and they stay with the bullets until they are gone.
One time I tried to remake an alloy that was working for low speed 45 bullets and got them too hard. When they mushroomed the nose would break off. Of course I found this out after they were powder coated and a few hundred were loaded. Now I make minimum 50 pound batches of alloy and mark the ingots. I really like 1-1-98, 2-2-96 and 3-3-94. My foundry type and pewter stay consistent but soft lead from the scrap yard might be 99% pure one time then 98.5% the next. If your "pure" lead isn't pure and you only want 1-3% of this or that in your final alloy, your final product can easily be richer than intended.
Another tip is let your antimony alloys sit at least a month before testing and longer is better. They will slowly harden, then plateau in hardness. Don't test expansion at various velocities before then. A bullet might mushroom nicely at 800 fps then two months later you do the test and it needs 850 fps.