How much Antimony

[HangFireW8]

Was thinkingh on a 80-5-15% lead-tin-Antimony mix for around 25BHN.(hopefully)
Is there any advantage in going over the 25BHN?

I'll find out soon, I got there without exactly trying.

After a first poor attempt at alloying pure antimony, and ending up with 12BHN ingots, I put all my scrap bullets and lead together with the oxidized remains of my antimony alloying attempt, and ended up with ingots at BHN 18-19. Hmmm. I was figuring around 9 or 10 BHN.

Casting them for 30 cal later and dropping them in water, I found that hardness of the non-frosty boolits was 21 BHN, nicely frostly was 30 BHN, and the partly frosty in between. While exciting, I ended up having to sort by frostiness. Obviously, all these boolits are not going to behave the same as they are not all the same hardness.

I am loading them in 3 batches, ~20, ~25, and ~30BHN. Fortunately the vast majority are in the last batch. All are gas checked.

I am also under no illusion that they will maintain 30 BHN. I will shoot them all within a month or two.

Anyway, the point is, if you go for super hardness, you'll have to watch your alloy temp and water tempering carefully for consistency, sort and load accordingly, and use them in a reasonable period of time before they age soften.

-HF

[anachronism]

For the best consistency, heat-treat your bullets instead of water dropping them. This way all the bullets will be the same temperature when quenching in water of the same temperature.

[armyrat1970]

Armyrat, what you say is technically correct, but I believe you're over-thinking the process.

When I ate lunch yesterday I had the last glass of tea from a gallon pitcher. When I drained the pitcher there wasn't any suger left in the bottom. When I emptied the glass there wasn't any sugar left in the bottom. Why???? Because the amount of sugar I put in the tea was nowhere near the saturation point; the sugar was completely disolved in the tea, it was in SOLUTION. When you excede the saturation point then the excess is in SUSPENSION and will stay there only as long as it's stirred. When you stop stirring the excess will precipitate out and what's in solution will stay until something is done to change the saturation point.

Antimony in Lead is very similar. The saturation point of Sb in Pb is ~3.5% and any more than that will precipitate out, even when its in a solid state.

But, add Tin and everything changes. One of the benefits of Sn is that it helps keep the Sb in solution. I admit that I don't know what the saturation point of Sb in Pb-Sn alloy is, but Linotype with 12% Sb is a very stable alloy and doesn't lose any Sb through precipitation.

Once disolved and in solution, it will stay there unless something changes to cause the saturation point to change.

Like I said before, It works for me. It's a simple process. It doesn't require any exotic equipment. It gets the desired results. It gets the EXPECTED results. So where's the problem?

Jerry

KYcaster i agree with you on some points. Check this site:
http://www.lasc.us/CastBulletAlloy.htm
Read down to when it explains Antimony in the alloy.

[Bret4207]

Old timers, take note. This is the new reality. WW are not always commonly available, and therefore not always the best option, or even an option at all.

-HF

True. Sad, but true. Still, if you're going to be mixing an alloy there is really no reason not to mix an alloy similar to WW, maybe with a bit more tin to aide fill out. WW is about perfect for 95% of the shooting most people do- plinking, target and hunting up to deer sized game. With the addition on a bit of Sn or Sb and some heat treating you can produce an alloy capable of almost anything a lead alloy boolit can do.

IMO the super hard alloys, those above 18-22 Bhn, are needed only for relatively few areas. Yes, there are the occasional barrels that just work better with them and high pressure/velocity sometimes requires super hard alloys. The extreme alloys over 30 Bhn...why not just use Zinc? It's readily available, can be cast using the equipment we have now and there ahs been some successful work done with it.

Just a thought.

[KYCaster]

KYcaster i agree with you on some points. Check this site:
http://www.lasc.us/CastBulletAlloy.htm
Read down to when it explains Antimony in the alloy.

Armyrat, There is a lot of good info on the LASC site, I refer to it often. I've read the article you cited several times before and agree with most of it, but there are a couple of significant errors in the text so, like everything else we hear or read, we have to try to separate the wheat from the chaff.

Quote from the article: " Heat treated lead, unlike steel, does NOT surface harden but achieves the same BHN all the way through." This doesn't have anything to do with Pb-Sb alloys, but I include it just to make my point. Precipitation hardening steels do indeed achieve the same hardness all the way through. Iron and mild steel can be surfaced hardened by heating in the presence of hardening agents such as Carbon or Nitrogen which results in a thin, hard surface layer.

Another quote: " Antimony can be purchased online from the “Antimony Man” but with its high melting point it is a somewhat arduous task trying to alloy it with lead. The Antimony Man supplies instructions on alloying antimony with the purchase that include the warning that the instructions must be followed precisely to be successful. In addition, antimony is extremely toxic, when handling it in a powdered form proper breathing protection and proper clean-up techniques of surrounding surfaces should be used." The instructions that Bill Ferguson supplies with the Antimony are essentially the same as I have described. (that's where I learned it ) The method involves disolving crushed Sb in Pb at temps of 700* F and lower.

Quote: "Melting temperature is 1167°F and even when melted at or above that temperature it is not easy to get a homogeneous alloy with lead." This statement, while true, is very misleading and makes me wonder if the author has really tried Mr. Fergusons recommendations.

Quote: "Lead/antimony alloy drosses considerably. As your melt reaches liquidus temperature that silvery, lumpy, oatmeal looking stuff floating on top is antimony. Skimming it off seriously depletes the alloy; it needs to be fluxed back into the melt." I've melted many tons of type alloys and the dross the author describes is very common, but it is not always present. With "foundry fresh" certified alloy it is greatly reduced and often nonexistant. I have begun to associate it with the presence of impurities such as dust and ink which provide "neucleation points" for the formation of oxides. That's just a theory of mine and until I find the time and resources to examine it I have no proof that it's true. Regardless of the reason for it's formation, it can easily be fluxed back into the melt just as he says.

I find many things in print that are at odds with my own experiences so unless I'm willing to investigate the reasons for the differences, I just have to accept the contradiction and continue to do what works for me.

Jerry

[243winxb]

Bullet Sizes & Weights – How to Vary Them
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

[armyrat1970]

Armyrat, There is a lot of good info on the LASC site, I refer to it often. I've read the article you cited several times before and agree with most of it, but there are a couple of significant errors in the text so, like everything else we hear or read, we have to try to separate the wheat from the chaff.

Quote from the article: " Heat treated lead, unlike steel, does NOT surface harden but achieves the same BHN all the way through." This doesn't have anything to do with Pb-Sb alloys, but I include it just to make my point. Precipitation hardening steels do indeed achieve the same hardness all the way through. Iron and mild steel can be surfaced hardened by heating in the presence of hardening agents such as Carbon or Nitrogen which results in a thin, hard surface layer.

Another quote: " Antimony can be purchased online from the “Antimony Man” but with its high melting point it is a somewhat arduous task trying to alloy it with lead. The Antimony Man supplies instructions on alloying antimony with the purchase that include the warning that the instructions must be followed precisely to be successful. In addition, antimony is extremely toxic, when handling it in a powdered form proper breathing protection and proper clean-up techniques of surrounding surfaces should be used." The instructions that Bill Ferguson supplies with the Antimony are essentially the same as I have described. (that's where I learned it ) The method involves disolving crushed Sb in Pb at temps of 700* F and lower.

Quote: "Melting temperature is 1167°F and even when melted at or above that temperature it is not easy to get a homogeneous alloy with lead." This statement, while true, is very misleading and makes me wonder if the author has really tried Mr. Fergusons recommendations.

Quote: "Lead/antimony alloy drosses considerably. As your melt reaches liquidus temperature that silvery, lumpy, oatmeal looking stuff floating on top is antimony. Skimming it off seriously depletes the alloy; it needs to be fluxed back into the melt." I've melted many tons of type alloys and the dross the author describes is very common, but it is not always present. With "foundry fresh" certified alloy it is greatly reduced and often nonexistant. I have begun to associate it with the presence of impurities such as dust and ink which provide "neucleation points" for the formation of oxides. That's just a theory of mine and until I find the time and resources to examine it I have no proof that it's true. Regardless of the reason for it's formation, it can easily be fluxed back into the melt just as he says.

I find many things in print that are at odds with my own experiences so unless I'm willing to investigate the reasons for the differences, I just have to accept the contradiction and continue to do what works for me.

Jerry

Jerry, that is one thing we do agree on. Experience in your loadings. I read a lot and take much with a grain of salt until I actually try it for my self. I feel if you find something that works best for you stick with it. But keep experimenting in case you can find something you can improve on. Nothing like proven experience in handloading from personal experience. There's so many different things involved in not only casting but just the actual steps of handloading each has to find what works best for them. It's all fun.