Question about alloy

[Jim P.]

I have this big chunk of lead I bought from a racer. It was cast in a small block chevy valve cover and it weighed 93 lbs. I cast some bullets out of it but it seemed to be real high in tin to me. My bullets come out real shiny almost like chrome and the top edge is real sharp. Some one suggested I mold a bullet from solder to see if my bullets are heavier to somewhat verify that my chunk has higher lead content than solder. Well my bullet made from the chunk weighs 126.74 grains. My solder bullet weighs 126.12 grains but the solder bullet has a radius on the corner like the solder has much more surface tension than the lead from my chunk. The solder bullet is also dull compared the other one. So my question is how else could I tell what alloy this chunk is?

[Winger Ed.]

It sounds like a home made weight for the race car.

I'd be surprised if it was made out of anything other than scrounged up tire shop wheel weights.

[centershot]

Scrapyards usually have an XRF analyzer, take a sample there and see what the composition is. If that's not possible, send a PM to member BNE, he can analyze it for you.

[Jim P.]

I melted down a wheel weight and cast a bullet with it. It weighs less than the other bullets but is harder.

bullet from my big chunk of lead weighs 126.74 grains
bullet made from solder weighs 126.12 grains
bullet made from wheel weight weighs 124.6 grains

The bullet from my chunk is the softest, solder bullet is next and bullet made from wheel weight is the hardest. The bullet made from solder is the nicest one. It cast a nice little radius at the base and makes inserting the bullet in the cases easier. The other ones cast with a real sharp edge at the base and sometimes a real small amount of flash at the base.

[243winxb]

I think you have close to pure lead.


Casting bullets
Bullet Sizes & Weights – How to Vary Them

--------------------------------------------------------------------------------


Quote:
The bullet diameters and weights presented in this list
are based on the use of Taracorp’s Lawrence Magnum
bullet alloy (2% tin, 6% antimony, 1/4% arsenic,
91.75% lead).
Bullet diameters and weights will vary considerably
depending on the lead casting alloy used. This variation
can be as much as 1/2% on the diameter, and 8% on
the weight among the most commonly used casting
alloys. For example, a .358-158 grain bullet might
show a diameter variation of .002", and a 13 grain difference
in weight.
Of the most commonly used alloys, wheel weights (.5%
tin, 4% antimony, 95% lead) will produce bullets having
the smallest diameter and heaviest weight, with
such bullets running approximately .3% smaller in
diameter and 3% heavier than bullets cast with
Taracorp's metal. Linotype will produce bullets with the
largest diameter and lightest weights. This alloy will
produce bullets approximately 1/10% larger and 3%
lighter than Taracorp. Other alloys of tin and antimony,
with antimony content above 5%, will produce bullets
with diameters and weights falling between those cast
from wheel weights and linotype.
Alloys containing little or no antimony will cast considerably
smaller than wheel weights and in some cases
will produce bullets too small for adequate sizing.
Within the limitations given above, the weight and
diameter of a cast bullet can be adjusted by varying the
alloy’s antimony content.
The size and weight of bullets of a given alloy will also
vary according to casting temperature. Higher temperatures
will result in greater shrinkage as the bullet
cools, thereby producing a slightly smaller and lighter
bullet than one cast of the same alloy at a lower temperature

[stubert]

What kind of solder? What % of tin.

[Jim P.]

What kind of solder? What % of tin.

I'm not sure. we have it at work. it's been around for years and it doesnt say anything other than wire solder. I found another chunk at work and made a bullet from it. This bullet is really hard. I believe its babbit

[Sam Sackett]

Yep. I also think you have almost pure lead. I have some from melted down dental lead and roof flashings. This casts a lot heavier than wheelweights and they also come out with a smaller diameter.

One way to check is to carefully watch the temp the alloy melts at. Pure lead is 621 and various alloys melt at lower temps.

Sam Sackett

[Jim P.]

Yep. I also think you have almost pure lead. I have some from melted down dental lead and roof flashings. This casts a lot heavier than wheelweights and they also come out with a smaller diameter.

One way to check is to carefully watch the temp the alloy melts at. Pure lead is 621 and various alloys melt at lower temps.

Sam Sackett

I weighed this bullet that I made from what I believe to be babbit and it only weighs 122.1 grains. Mixing some babbit with the pure lead would harden it a bit wouldnt it?

[Drm50]

The tin content allows for the sharp defined edges. The flash may be from mold being to hot or the metal needs a little more cooling time. There is not really any way to tell you anything other than a guess. I strive for defined square edges on all my bullets. Depending on what cartridge and use of boolit it may not be something to worry about.

[243winxb]

Babbit has copper. Not good for casting if the % is high. It will plug a bottom pour spout.
http://www.neymetals.com/product/babbitt-metals/#:~:text=The%20alloy%20mentioned%20in%20the,metals %20as%20the%20major%20element.

[Jim P.]

The tin content allows for the sharp defined edges. The flash may be from mold being to hot or the metal needs a little more cooling time. There is not really any way to tell you anything other than a guess. I strive for defined square edges on all my bullets. Depending on what cartridge and use of boolit it may not be something to worry about.

here is a picture of 2 bullets. You can see how sharp the base is on the one. The one with the small radius at the base is actually made from solder, so I would think it is pretty high in tin.

https://i.ibb.co/pZjbzVB/20210121-174646.jpg

[P Flados]

I seem to recall that you previously reported your "chunk" lead to be around 9.8 BHN.

Given that you now know that it is heavier than wheel weight lead, I would say you probably have a mix of pure lead and wheel weights. It is what was typically used for a general purpose "home made" weights 20 or more years ago. Other than being a little on the soft side, your "chunk" lead sounds like a really good "bullet alloy".

Solder for electronics is most commonly 60% tin, 40% lead. General purpose solder for mechanical assembly is probably going to be between 50% tin, 50% lead and 40% tin, 60% lead. Special solders used for automotive radiators and some plumbing applications had a much higher lead content (say 70% to 90%) to get farther away from the Eutectic point (lowest melting point, 63% tin, 37% lead). Your solder sounds like it has higher than typical lead content.

The Babbitt is generally a great additive to make soft lead harder.

If your chunk lead is hard enough to shoot good in your gun, I would use it as is.

If you want to try a little harder make a small batch of a couple of pounds and mix in say 3% Babbitt. Make at least one small ingot for hardness testing and cast some bullets to try it out.

Remember that you are likely going to need to acquire more lead in the future. Unless you have a reliable source of hard lead (like truck stop wheel weights), you are likely to find many sources are pure or near pure. Your solder and Babbitt will be real handy to have around if you end up trying to get a good sized batch of pure converted to good bullet alloy.

[Jim P.]

I m going to get some wheels weights to melt down tomorrow.

[Jim P.]

Im not positive about the hardness of the lead. I have a tester for testing the pressure of coil springs. I put a 5/32 ball on it and placed the lead on the ball and put it in a small arbor press and I bring the press down until the spring tester reads 60 lbs. I then measure the indent with digital calipers. I am pretty sure the spring tester is accurate but I could be getting some error in measuring the diameter of the indent. I am a machinist but measuring the diameter of the indent is not an easy thing to do with calipers as you probably already know.