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Petrock
09-24-2010, 06:05 PM
Hello,

I've run across a supply of lead that is seven parts lead and one part antimony. What I would like to know is if this is acceptable for casting boolets and for what firearms/calibers.

Byron Cromwell
09-24-2010, 06:27 PM
Petrock:
That works out to about fourteen percent antimony, which is a little bit too hard for any application I have read or used. Twelve percent antimony is about tops for bullet casting as the metal becomes too brittle. Suggest you cut it one to one with wheelweights (either clip on or stickies) and add about two percent to four percent tin by weight. That'll give you about seven to eight percent antimony and two to four percent tin which is good hard boolit metal. This works good in auto pistols, smokeless rifles at high velocities and full-house magnum handgun loads. You need the tin to make sure the bullet metal will fill out properly in the mould.
This metal is not as good for low velocity smokeless, or black powder loads generally as the metal would be too hard (I'm not saying it won't work, but not as well as soft lead with no antimony). If you're casting hollowpoints it would also be too hard and the bullet either would not expand or would shatter. But I'd cut it one to one with wheelweights.

Byron

mike in co
09-24-2010, 06:40 PM
not as is..but thin it out by addding pure/soft lead and very useful,,,,so only if the price is right..

mike in co

runfiverun
09-25-2010, 12:25 AM
you'll definately need to cut it and most likely use some tin.

jmsj
09-25-2010, 12:36 AM
Petrock,
Welcome to the site.
I would grab up all you can. Like the guys have posted cutting it w/ pure lead or wheel weights and adding 1or 2 percent tin will give you a useable alloy.
As to what firearms/calibers, it would help to know what you want to use it for. Check out www.lasc.us , they have lots of info on alloys, recipes, BHN versus pressure, heat treating, etc.

lwknight
09-25-2010, 01:23 AM
Be advised that you will get a lot of slush from the antimony being that high percentage.
Don't scrape it off and toss it out. It is your antimony. About $7.50 per pound value.
Adding tin will help keep the slush from trying to be floaty.

excess650
09-25-2010, 06:45 AM
If he adds 4% tin he has linotype! Lots of guys shoot linotype, but lots of guys use linotype to enrich their soft lead.

Petrock
09-25-2010, 08:03 AM
So adding 4% tin would give me a good alloy for hard bullets. We were thinking of making some .44 Mag and I've heard that what I've got might make some good high speed rifle bullets. Maybe something in .308 for a savage bolt gun.

Can I use cast bullets in my M14s?

Petrock
09-25-2010, 08:04 AM
The other consideration is that if I get enough of this stuff I might just make some ingots and sell/trade my surplus to fund other projects.

missionary5155
09-25-2010, 08:38 AM
Good morning & Welcome Petrock !
I would use it as a lead additive. 20-1 is a waste of good tin... I only add tin IF the particular mold does not fill out easily. I rairly mix past 40-1. Sometimes with WW I will add about 1 %.
Yes you can use Cast in a M1A... I use the RCBS 180 GC at around 2200 fps . I have used 2460, 4895 and 4064 is good results. I size at .310 Both my M1A´s chug right along. This loading work nicely in the FAL also.

snuffy
09-25-2010, 01:43 PM
I always was told that antimony would NOT alloy with lead WITHOUT tin being present!? And, a certain percentage of tin must be present to allow a certain percentage of antimony?

You get pure lead with suspended antimony crystals without tin present. It acts like pure lead when pushed too hard.

lwknight
09-25-2010, 02:42 PM
Snuffy , you are very correct. Thats why the antimony gets slushy and tries to float out without tin. Anything more than about 3% antimony will not tame without tin as a mediator.
The 2% tin in 6% antimony hardball was not by accident. You need the 2% to keep the alloy smooth and totally liquidous.
When you get higher antimony like the 12-14 % range you will need 4% tin to tame it down. The 4-12-84 was no accident either.

Its just my guess but , I suspect than when the ratio is in balance that it will always be eutectic. When I mixed 1 to 10 tin with my superhard I got 9-27-64 and it came out eutectic. Same tin to antimony ratio as linotype . Yea , it just set up directly from liquid to solid within 30 seconds of when it started showing signs of hardening and that was a 25 pound ingot.

Petrock
09-25-2010, 08:14 PM
So how do I tell what I've got then? The information available lists the lead as being "7 parts lead and 1 part antimony". Some of the stuff is a light dusty lead colour. Some of it is almost a blue/grey.

It is definetly hard, I can't get my finger nail into it. But there are marks where some of the lead has been squashed against other parts, making dents.

garandsrus
09-25-2010, 08:23 PM
Petrock,

Are you sure that the mix isn't 7 parts lead and one part linotype? This would be a much more common mixture. Linotype does contain antimony. If it is 7:1 lead to linotype, the alloy would be 98% lead, .5% tin, and 1.5% antimony which would be good for just about anything you want to do.

An alloy of only lead and antimony is not very common and I expect that the person you talked to just used the wrong word.

If you have a recycler nearby they may have a "gun" that can tell you the exact alloy in about 5 seconds.

John

Petrock
09-25-2010, 08:25 PM
I got the information right out of a technical manual. This stuff is really old. Some of it may go back to the 20s.

runfiverun
09-25-2010, 08:32 PM
the antimonial lead alloys have many uses.
they can be extruded,or swaged.
often times water pipe is dead soft but has antimony in it.
chemical pipe also has antimony.

Echo
09-25-2010, 08:44 PM
I know that some authors mention casting their boolits out of lino, but it seems to me that most folks on this forum wouldn't think of it - too hard.

If I had some 7/1 alloy as mentioned above, I would cut it considerably with WW's and add some Sn to bring it to something like hardball (92-6-2).

lwknight
09-25-2010, 09:11 PM
If it has the grey dusty powder on it then its not mixed with linotype or anything else having tin.
Of course it feels hard. It is 12.5% antimony which is surrounded by pure oxidizing lead.
Without tin its just pure lead that feels hard and really is soft. Its an illusion.

Imagine a hard steel sponge full of jello. The jello would be most of the weight and it would be hard and scratchy even with pure soft jello in it.

The antimony crystaline structure is water in sand or hard clay that soaks up water into its structure. Add some cement and you get a hard homogenous rock.
Same with addng tin to the antimony lead.

lwknight
09-25-2010, 09:18 PM
So how do I tell what I've got then? The information available lists the lead as being "7 parts lead and 1 part antimony". Some of the stuff is a light dusty lead colour. Some of it is almost a blue/grey.

It is definetly hard, I can't get my finger nail into it. But there are marks where some of the lead has been squashed against other parts, making dents.

Melt it. See what it acts like. Check the melting temperature.
If its just antimony.lead the temp will be around 600 degrees or slightlty less.
If you find it at 570 or lower then there is tin presant.
If it melts at 500 or lower then its linotype.

Even the hardest of hard alloys will dent against each other or concrete.
Even steel will dent against concrete or another piece of steel.