strange alloy?

[bbekalb]

alright guys, so i was melting some range lead (someone was shooting some VERY hard alloys) and while stirring the pot I discovered something weird. I'm usually good at identifying metals, but this threw me sprawling. it had a yellowish color while hot, and did not melt. I cast in an odd way, and make small batches with a blow torch. I tried to melt it after pulling it from the pot to no avail! That torch melts aluminum in small quantities like nothing, and this stuff didn't even get malleable. another odd thing was the tip of the bullet. It looked like a soft alloy being shot too fast, and being mangled by the velocity (if you guys get what i'm trying to say.) So I'm stumped. What could it be?

[I'll Make Mine]

Sounds like you found a steel core from surplus ammunition that had been deformed by hitting a steel plate, target frame, rock in the berm, etc. Assuming steel, it should float in your alloy; the other kind of hard core found in some surplus ammunition is tungsten, which is one of the few things you might find in salvage that will sink in your casting lead.

[bbekalb]

it sank....

[I'll Make Mine]

Well, there you go. Tungsten and gold are the only reasonably common metals that will do that (platinum group, including palladium, rhodium, osmium, etc. will, but you're unlikely to ever see those in bullets, or even in pieces bigger than a 3 mm spherical bead). I'm pretty sure you'd have noticed if you had a gold bullet core... ;)

Tungsten won't melt with any heat source you're likely to have -- oxy-acetylene will just barely get there, but tungsten also starts to burn before it starts to melt (break the glass off an old style tungsten light bulb to see what I mean; the filament will burn in the air even though it never gets hot enough to melt in normal operation).

[bbekalb]

thanks guys. tungsten it is.

[I'll Make Mine]

FWIW, it used to be possible to buy surplus .30-06 machine gun ammo in armor piercing with tungsten penetrators. I suspect that's the source of your mystery metal.

Of course, I forgot to mention the possibility of depleted uranium (another metal that will sink in molten lead) -- but if you got it above about orange heat, it'd burn and you'd be dying from inhaling the smoke. It's used for the penetrators in modern US military AP ammo (.50 BMG and up only, AFAIK), because it penetrates as well as tungsten, but ignites from the friction heating as it penetrates and bounces around inside the compartment, burning as it goes. Nasty stuff (and yes, it's a little radioactive, but that's the least of your worries if someone is shooting it at you).