You can't go wrong with this boolit:
That's the lee 124 rn 6
cavity mold. It's either 2 or 6 cavity from lee.
For my CZ 75B, I have to cast these very hard. I use a range lead alloy, that has enough antimony and tin in it to be water dropped directly from the mold. It results in a 21 BHN boolit, that shoots as good as a FMJ copper jacketed or plated bullet.
A bucket with about 6-8 inches of cold water will quench about 500 boolits, then it should be changed for some fresh cold water.