CF the real answer to your question is you just need to take the time to go out and prove it to yourself to see if it actually does and its a daunting task to say the least. In your case it would probably not be worth the time and effort spent being a casual shooter. In my case being a cast bullet benchrest competitor trying to get everything out my rifle that is has to offer it indeed is worth it for me to do so. My comeptitve rifles are not at all real picky and most aren't but they all do have their own individual desires that will take them from simply being competitive to becoming extremely compeitive and the differance between the two is not small the gap is actually quite substantial. 

JLouis

Derrickman your friend probably does indeed have the best as well as the easiest approach. When you have found a hardness that works take a bullet out of that batch of bullets cast that weighs the same as others within a few tenths and set it safely aside. It is then used as the hardness test example by weight for all future alloy batches being made and probably the most accurate approach and the one I use. If the bullets gain weight there is lack of tin and if lighter there is to much tin. But you do also have to have the casting temp. close to always being the same for best results.

JLouis

I have never worried about testing hardness.  I use roof flashing or scrap x-ray room lining lead.  It is pure lead for practical  purposes.  I buy pure tin from Nonferrous Metals in Seattle.  I weigh the lead on a digital scale, divide  by 20,  convert to grains and weigh the tin to +/- a grain.   My alloy is 20:1 with 21 total parts.  30:1 with 3 total, ect. 

A freind with an LBT tester told me it was the most accurate he found, but still had variations in the same  batch of alloy that indicated to him testing hardness is a waste of time for a known alloy.

Thank you Schuetzenmiester. "Testing hardness is a waste of time" sums it up perfectly!

Not that it really matters but I beleave 20 parts lead and 1 one part tin equates closer to being 4.76% tin and 95.2% lead and not actually 95-5 and if one reads the fine print from the manufactures it also clearly states the hardness as being approx.10 as Kieith's sites pointed out but I don't think it really actually matters.

JLouis

  Would you show us the math for that ?

After the zinc contamination episode, if I don't know what it is, I don't melt it.   You can test for zinc with Chlorox.  Zinc oxide will bubble out of a chlorine water solution.

I have never had an issue with the lead I got from a local lead shop.  Probably won't have trouble now because I probably won't live long enough to run out. Lead flashing  is going away.  Major corporations in the Sea-Tac area banned it from their project many years ago. The lead shop guy retired just in time before the EPA banned it everywhere.