Question.

fiver

Well-Known Member
the foster slugs are probably [more likely] swaged and not cast.
I know Hornady uses 5% antimony in their swaged handgun bullets and sierra used to use 3% antimony and nothing else.
tin in swaging makes things more difficult on the equipment but does have down range uses.
it's not something I'd want to try at home without some super fancy foot work.

anyway what happens is the higher antimony content actually makes the swaging easier because the antimony crystals break down and this allows the lead to extrude and flow easier.
they aren't tied up in any bonds or chains so are pretty much just floating around within the pure lead.
 

CWLONGSHOT

Well-Known Member
OK. I grabbed a bag of magnum shot. I wanna experiment.
What ratio would you guys guess would get me at least a 9/10 BHN?
CW
 
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CWLONGSHOT

Well-Known Member
SO... STRAIGHT shot wont make near 10BHN...

But its arsenic/antimony will allow my cast to quench harden or harden with time...

What ratio would ya suggest? I received some 6% Antimony ribbon from a supplier to make up harder alloy. Once I get what I need he will take and animalize and produce that mix for me. He dont know hardnesses just composition.
 

fiver

Well-Known Member
6% antimony will make over 10 BHN air cooled, it will make 15 no problem.
those numbers above are for shot and was produced by someone that doesn't know lead alloys very well.
what they DID get correct was the antimony content and that is what we as bullet casters are concerned about... sort of.

anyway to get to about 10 BHN all you really need is around 2% antimony.
BHN and antimony relationship is a sliding scale but not really a linear one.
lets look at things.
linotype 21-22 bhn 12% antimony, 4% tin.
hardball or teracorp magnum alloy is linotype cut in half with pure lead, but has a bhn in the 15-16 range.
your nowadays ww's are about 2.5-3% antimony but clock in at around 11-12 BHN.
you can see BHN and interior matrixes move with each 50% reduction but not by half, more like it takes 4 times less antimony to make a 50% reduction in BHN.

the key is not only what is in the alloy but how the alloy is cooled or formed into shape.
if you swage or extrude 3-5% antimony lead alloy you have broken down the antimony crystals and your BHN is now almost that of pure lead and the alloy will act like pure lead.

if you cast and quench that 3-5% alloy into cold water your BHN shoots up.
if you air cool the alloy in a 75-80* room your BHN should be pretty close to what you'd expect.
do the same thing in a 20-F room with a breeze and you'll pick up a few BHN points because of the quick cooling.

now that your completely more confused.
your really only looking for around 2% antimony to make 9-10 BHN for our purposes.

if I was specifying and had to pick one I'd go with something more like 2.5-3% antimony [and add in my own tin as necessary] that'd put me closer to 12 BHN but with a wider range of manipulations for my needs.
 

Rick

Moderator
Staff member
My clip on wheel weights with an added 2% Sn consistently run 12 BHN. I assume wheel weight alloy at 2% Sb and 0,5% Sn with a touch of As. This alloy will heat treat very easily to just about anything you may want though I rarely do anymore, little of my shooting requires it.

If you want to make this simple and you have someone that will blend the alloy for you simply have him make WW alloy with 2% Sb, 2% Sn and 0.25% to 0.5% As.

The Sn has a minor hardening effect and is self limiting in that more will not make the alloy harder. In fact the higher the Sn percentage the more the effect of quenching is limited. At any rate never use more Sn than Sb.
 

fiver

Well-Known Member
and I think this is where people get confused.
they see 2meh percent antimony from one guy and he says 12 BHN, then the next guesses in closer to 3% antimony on his slightly older ww's and lesser tin alloy but then he throws down a 12 BHN number also.

okay so weelll flip I only want 10 BHN [shrug] so how do I get there.

well you could try to get down to minimal antimony, run no to maybe 1/2% tin.[except then the tin acts as a grain refiner inside the alloy and not a surfacing agent which is then another whole discussion]
or you could cast in a boiler room during august and test the hardness in like 2 hours.... LOL

anyway 1/2ish percent this or that or 1-2 bhn one way or the other isn't really all that important.
what you really want is to have a reliable repeatable consistent alloy that comes in close-nuff from batch to batch.
your gonna add in more variables when you cast anyway.
humidity, air temp , pile size, water temp, wind, mold,,, blah,blah,,, whatever.
 

CWLONGSHOT

Well-Known Member
Fiver, thank you. I read and understand to a point but application is where im lacking..

what I want from him is a alloy I can manulipulate to harder as needed but not be too hard for general-purpose handgun alloy... IF I CAN.

SO I want say 10bhn. That I can say quench to a 15 ish and maybe heat treat more as infrequently warranted. Ill make my own 20:1 & 16:1 as its just lead tin and a scale.

my worry is HOW he makes that alloy. Worried what he may have may not temper as Im expecting.

he gave me about 5# of "6%Antimony tape". It looks like quadruple thick aluminum tape for duct work.... seems as flex as dead soft. But dosent scratch so it is harder than DS.
I have a LBT BHN gauge and will test as best I can before anything.
But he is wanting me to get a hardness I want. Give to him to test for content and he will duplicate and provide me with ingots.


Im mean time I wanna cast a 1/2 pot tonight and would like 10 ish bhn. Do ya have a suggested ratio I toss in? Say 4# mag shot and 6# soft?? Opposite? (I have tin as well)

I have read about Adding pure copper powder too... Anyone try that? Or is it mow becoming alchemy?
CW
 

Rick

Moderator
Staff member
Copper for 10 BHN? Your getting wrapped around the axle on this, making it way more complicated than it needs to be.

My WW runs about 10 to 10.5 BHN WITHOUT adding the tin. Right at 12 with the tin. My WW's tested at 2% Sb, 0,5 Sn & 97.5% Pb.

Lamar is absolutely correct, a consistent (hardness, toughness, BHN) is far more important for accuracy than hitting a specific BHN.

If your alloy has Sb in it it will quench harden. Period. How much and how fast is regulated by how much Sb and how little Sn.
 

Ian

Notorious member
well you could try to get down to minimal antimony, run no to maybe 1/2% tin.[except then the tin acts as a grain refiner inside the alloy and not a surfacing agent which is then another whole discussion]

Haha, yeah. THAT sure doesn't get talked about much. Spindrift just inadvertently discovered that by comparing the castability of nuke containers to .22 range scrap with added tin of the same bhn.
 

fiver

Well-Known Member
without knowing which shot you have I can't say.

look at the chart above 'magnum' shot runs the gamut from 2% to about 6% antimony.
in one scenario you'd just melt the shot down and throw in some tin.
in the other one you'd mix 3 parts soft to one part shot, and bump the tin again.
either way you get 2% antimony and whatever tin you add and end up right close to 10 BHN when you air cool.
you'll also have to wait about 7-10 days for everything to settle down enough to know if you hit 10 or 11 BHN.
[another variable]

copper adds another variable to the equation, it doesn't change the BHN enough to notice but it adds a toughness to the alloy.
that toughness resists shearing but doesn't affect the malleability.

this is probably gonna get pretty deep here in a couple more posts, and each small change will start to affect the rest of the alloy.

we are starting to get into boundary effects and altering molecular chains by using free radicals to almost form a tied together 4 strand chain that is only held together by one of the intermetallic components, and the other two parts are basically ignoring each other.
now you notice I called it a 4 chain strand even though there are only three components [ignoring the lead itself here]
that's because the boundary layer of copper is around the free or trapped [if quench cooling] antimony but has almost nothing to do with the SbSn chain also trying to tie into the Sb while also supporting the PB in it's own way.
so you basically end up with layers of broken and stretched antimony crystals trapped in the quenched alloy surrounded by thin layers of copper and also have SbSn support chains throughout the alloy.
kind of the opposite of what happens if you run too much tin with an antimony alloy.

I hope that typed out like I thought it out.
and now were really off track.... LOL.
 

CWLONGSHOT

Well-Known Member
Well...

Last night I 1/3ded the bag of shot. 8# was dumped in my 95% empty 20# pot. I added 6# of soft lead and melted. I tossed in 4 tin slugs for about 3 oz. fluxed twice with wax and once with fresh pine saw dust.
NICE CLEAN LEAD!!

i cast up a few from a new Arsenal 45 mold. Air cooled on a dr

This am I tested it on the LBT tester.

aa.jpg

I might try oven tempering some of what I powder coated.

in mean time Ill test this bulletover comjng weeks.
CW
 
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fiver

Well-Known Member
it's right side up for me.
give them a week and try again.
6 is 1 BHN over pure lead.
the tin alone should bring pure lead up to close to 10.
 

Rick

Moderator
Staff member
it's right side up for me.
give them a week and try again.

6 is 1 BHN over pure lead.
the tin alone should bring pure lead up to close to 10.

Yes, in a week the picture will be once again upside down. :rolleyes:

My stick-on weights are 6-6.5 BHN and 2% Sn brings them up to 8 to 8.5.
 

CWLONGSHOT

Well-Known Member
OK...

Tonight I cast a 16:1 alloy. Boy thats a EASY ONE!! 16 oz to 16#!!
Anyhow. I tested my 50/50 bar stock and got a few numbers...from 13.5 up to almost 18!!!
Anyone know what 50/50 "should" be in BHN?

I just cast it all using a Lyman 357446 mold. Three different samples measured almost 8 bhn less then a hour after casting.

Question; Will this harden with time? I bought this 50/50 its an u known source. But the lead is known trusted and pure lead.

CW
 

CWLONGSHOT

Well-Known Member
Well...

Last night I 1/3ded the bag of shot. 8# was dumped in my 95% empty 20# pot. I added 6# of soft lead and melted. I tossed in 4 tin slugs for about 3 oz. fluxed twice with wax and once with fresh pine saw dust.
NICE CLEAN LEAD!!

i cast up a few from a new Arsenal 45 mold. Air cooled on a dr

This am I tested it on the LBT tester.

View attachment 15328

I might try oven tempering some of what I powder coated.

in mean time Ill test this bulletover comjng weeks.
CW

I just re tested this one. (Cast 6/9) Its now almost a 9BHN.
CW

EDIT: I just tested the powder coated and quenched. Its a solid 10BHN. :p
 
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