Another alloy / material question

[NHlever]

I bought something over 300 lbs of bullet metal in ingot form from a gunshop that got it from the estate of a guy that was a metalurgist, and bullet caster. About half of it was labeled as 1-15, #2, or Lead. There were two boxes that weren't identified. Yesterday I cast a bunch of bullets from one of the boxes, and have pretty much determined that the material is Lead, or nearly so. The bullets are softer, heavier, and smaller in diameter than bullets cast in the same molds from wheelweights. The other unidentified box seemd a bit harder than the lead, and somewhat lighter in appearance. I melted some today, and cast some sample bullets from it, and got quite a surprise since I expected that it was more lead, or perhaps wheelweights. First, I noticed a gold colored layer on top of the molten metal turning to bluish if the heat were turned up. When I poured the first bullets, the sprue was very difficult to cut off, and had an almost chrome appearance. I continued casting with three different .44 molds. I also noticed that the bullets filled out almost perfectly the first pour in cool steel molds (Lyman, and RCBS). The material also seems to melt at a lower temperature. When the sample bullets cooled I weighed them, and found them to be much lighter than bullets cast from the lead, or wheelweights. They all are nominal 240-250 grain bullets, and the bullets I poured out of this material weighed around 200 grains, and are noticably different in color....... more chrome like, and mike .002 smaller than bullets cast of wheelweights, and .001 smaller than bullets cast of lead. Oh, the other thing is that it takes the sprue, and ingots cast from this material much longer to solidify. I think I have 60+ pounds of Tin! Do you all agree that this could be likely, or do you have different ideas.

[mold maker]

Did the former owner only work with bullet casting alloys or did he also work with precious metals?

[runfiverun]

i am thinking tin also

[felix]

Tin? Maybe the majority of it, but the remainder prolly is not pure lead. Obviously, no antimony. The monkey in the wrench is that it takes too long to solidify. Solder would not be solder if it did not solidify very quickly. Might be some experimental solder that did not meet the application test. Try some loads with it mixed into some high antimony stuff you have laying around. You need to get the weight of the boolit up to maintain accuracy expectations at a hunnert. It's a matter of twist which might not satisfy that light of a 44 boolit with that length. ... felix

[NHlever]

Did the former owner only work with bullet casting alloys or did he also work with precious metals?

The former owner was a gun crank, and I doubt that he did any precious metal work. He set up investment casting foundries all around the world, and ran the one for Sturm Ruger.

[NHlever]

Tin? Maybe the majority of it, but the remainder prolly is not pure lead. Obviously, no antimony. The monkey in the wrench is that it takes too long to solidify. Solder would not be solder if it did not solidify very quickly. . ... felix

Felix, that is what makes me think that it has no lead, or antimony in it. I don't have any high antimony material. All I have is a small amount of wheelweights, and some bird shot. I do have some commercial cast boolits, but I'm not sure what alloy they use.

[Lloyd Smale]

my first guess would be tin but it possibly could be foundry type.

[richbug]

Sounds like a high tin content babbit, maybe even a Nickel Babbit. Nickel babbit will get that goldish color, is relatively light, and tough as nails.

[NHlever]

All good input for sure! I mixed up a batch of alloy containing 10lb of lead, 1lb of bird shot, and 1/2 lb of the mystery material. The resulting bullets weighed the same as bullets cast out of the same mold with wheelweights.... After supper, I'll check the diameters, etc. At any rate, I have quite a few boolits out there to shoot, and see how they work. :-)

[fourarmed]

If the mold casts 250 gr. with lead, and 200 gr. with the mystery metal, then its specific gravity is around 9, which is much too dense for tin (SG about 7.3).

[runfiverun]

nickel babbit is plausible you may also have some silver in there.
i wouldn't worry about it too much, use as little as possible, and look for more lead while shooting what you have.

[NHlever]

If the mold casts 250 gr. with lead, and 200 gr. with the mystery metal, then its specific gravity is around 9, which is much too dense for tin (SG about 7.3).

Hmm, looks like I don't have the answer yet........ it is also possible that the "lead" that I cast the other bullet from was not pure. I'll have to try that again with something more known. I just went out, and weighed the actual boolits again, and the "lead" one was 264 grains, and the "tin" one was 199.8 grains. I did some checking on the specific gravity of different materials since I think this is a really good approach, and found that the numbers almost exactly match 50%Pb / 50%Sn or 50/50 solder. That sounds plausable doesn't it?

http://www.reade.com/Particle_Briefings/spec_gra.html

[fourarmed]

50/50 would have a specific gravity right around 9, so that may well be what you have.