I was given recently a block of “lead”, with no idea of what it might really be, other than scavenge. It was probably intended for fishing sinkers before it came my way. Sheet lead? Wheel weights? Battery? Most likely candidate was salvaged sheet lead.
Batteries are of course a no-no for bullet casters. The fishing sinker crowd don’t seem to know about that though.
One reason for testing was to consider the battery possibility.
The test was going to be density. I have a Lyman #32359 mould for my .32-40. With dead soft lead it casts 122.5 gns. If that was the weight I got out of the test material, I’d call it sheet lead. If it was a few grains lighter I’d call it suspicious.
In the event, the bullets came out at 122.5 gns, and were variable quality typical of straight lead. So the lead is a keeper. Now to make it useful.
I was also given by another friend some material that looked like it was cut in ½” strips from a black painted sheet approx. 3/8” thick. My benefactor thought it was solder, and the exposed sides lacked the tarnish I would expect from lead. IF this was solder, a 4% addition to my new lead (looking for about 2% tin) would shift the bullet weight by about a grain.
And yes, the new bullets were 121.6 gns, so I’ll call the other stuff solder. The new alloy casts well and made good bullets, so I kept casting and made the 200 or so I needed.
My point is that with nothing more than a knowledge of expected bullet weights I was able effectively to identify both the gift lead and the purported solder.
In a more general sense, I control my bullet alloys by blending to a previously established weight/alloy – add linotype or hardball to make bullets lighter/harder, or soft scrap to make them heavier/softer. I am currently using two alloys, based on bullet weights, a soft alloy for subsonics and a much harder alloy for hunting and for LAS Ram loads.
Before I melt a pot of “unknown” I weigh it, and once it is melted I cast 20 or so bullets to get a bullet weight for that metal. If I intend using it straight away, I can then mix in however much is needed of a harder or softer alloy, for which the bullet weight is known, to achieve the desired end weight.
Tin and antimony are of a similar density, and both are less dense than lead. Bullet weight will therefore give a very good indication of the % of “non-lead” in an alloy. In the harder alloys, the hardness graphs would suggest that 1% or so each way of tin versus antimony does not make a big difference to hardness. Given that my “hard” addition usually is either linotype (84,12, 4) or hardball (92, 6, 2) the tin:antimony ratio pretty much looks after itself.
When I finish casting I make the leftovers into ingots and label them with the bullet weight. All of this is done with an open pot and dipper.
Edit: The comparative densities i have for lead, tin and antimony are 11.13, 7.26 and 6.68, although I suspect that the values might be slightly different when considering the effect of each on the density of an alloy.