As you fellers know its been 20 years since this country used lead wheelweight metal for wheelweight balancing so those days of going to the local tire shop and coming away with several hundred pounds of lead for 5c a lb (or free if you hit it lucky) are loooong gone. So us old bullet casters have been scrounging whatever came along for many years.
My friend George is a garage-sale addict. Every now and then he gives me a call and says he's found some item of shooting/reloading/casting interest and over the years has picked me up several hundred pounds of casting metal, usually in the form of home-cast fishing sinkers. All the home-cast fishing sinkers that fit in my pot have gone directly in assuming them to be wheelweight metal and as far as I can tell this has been a valid assumption. He has come up with the occasional commercial cast fish weight and the old thumbnail test has showed these to be pretty much pure lead and I have set them aside for that purpose (you know -- when you want soft boolits for muzzle loaders or target velocity revolver bullets).
But I had set aside two boat anchors (about 30 lb each) and two powerline weights (also about 30 lb each) that seemed to be harder than pure lead, as well as a total "mystery metal" consisting of what looked to be a pile of drips falling into pine needles from some unknown adventure (about 25 lb of this weird-looking mess). Yesterday I fired up the big melting pot which is a propane-fired turkey cooker with a nicely sized cast iron roasting pot. Melted down the different metals and when I had them nicely melted and ready to be cast into ingots I cast a couple boolits from each using my trusty 45/70 bullet mould that casts up 532 grains from wheelweight metal.
Years ago I built a spreadsheet by applying knowledge gained from high school physics where I used the atomic mass of lead, tin, and antimony to predict what the weight of a bullet would be when cast of a number of different alloys of those three metals. So both the powerline weights and the boat anchors cast up boolits that run about 536 to 537 grains. Pure lead should be 537 grains according to my spreadsheet, so these go into the "pure lead" pile. I think it was just some sort of "age crusting" fooled my thumbnail test. But that weird mystery metal gave a boolit weighing just 490 grains. And a hard and tough bullet it is, too according to my "pound with the hammer" test. Even linotype should make a boolit a bit over 500 grains, so this is something with even more of the tin/antimony than linotype. My spreadsheet says "stereotype" would give a 494 grains bullet, so this is probably stereotype. I never found stereotype before in all my scrounging adventures. What a neat deal for alloying up some hard bullets! I just wish he'd found a whole lot more of it.
Anyway, I just thought you other old bullet casters would appreciate hearing of my boolit metal adventures.