Re: Lead Hardness
Wheel weights are (if I remember correctly) about 80% lead and 20 antimony with a small amount of arsenic as a grain refiner. I use pure WW for my cast rifle bullets in the Sharps and scavenged range lead in the pistol. If I want something in between I mix the two 50/50. I also add a small amount of tin to the melt to aid in "wetting" to the mold.
WW after casting respond well to heat treating and they will harden significantly over time. This is because of the arsenic in the alloy along with the antimony. A mix will harden too, just not to the same level of hardness. If you cast WW it would be a good idea to let them rest for a month, or heat treat them at 450 F for one hour prior to lubing/sizing.
I've never owned a hardness tester, but it's a tool that has it's place if you are looking for something specific. Casting for pistol won't be as taxing as finding an alloy for a rifle that works well.
There is a wealth of material out there and I recommend you spend some time perusing the lasc website. It will answer all of your questions. It's a great resource.
Life's too short to shoot an ugly gun.....