Friend gave me 200 lbs of lead from his dad and I figured that it was ml type as well as coww lead. I put about about 10 lbs in some bhn 10-12 bhn and after the first cast I had to use a rubber mallet to get the sprue cutter to cut the sprues. Boy howdy that lead is hard. My guess is linotype, which I did not expect.
Went to Lowes and picked up an awl, scratched a pure lead ingot and some scrap from the pour. The pure lead was a deep scratch, the scrap was a very light scratch. So I'm going to test all the ingots with the awl and segregate them into soft, medium and hard. Probably trade the linotype for pure lead.
The scratch method actually works a lot better than I thought it would. And for 5 bucks I'll take the lack of precision.