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Best Pouring Hard Alloy

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Dead soft pretty nearly pure lead pours very well.  I've been buying near pure lead from roto metals for years for testing.  In the real world a harder alloy, not brittle, would be better. I'm not looking for suggestions for scrap lead or salvage lead or "I use so much wheel weights" or anything like that.  

I'm looking for a harder tougher lead alloy that still casts relatively easily. An answer from somebody who's knowledgeable and can possibly provide approximate percentages of other metals in the alloy.

Edited by CNC Molds N Stuff
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i use 6% antyimony in spincasting.  it will be hard (no pun intened) to break off the spru in hand pouring. when I have a difficult pour in hand pouring I will use hard lead because I think it casts easier.

last time i checked, roto only sells lead with around 4%

linotype runs around 10-12% andtimony.

I have hand poured 6% and that is plenty hard, I wouldn't call it brittle but breaking off the spru can leave a hole where it breaks off. 

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I don’t have the percentages like David but I do use a lot of lead that has antimony in it.  It is a lot harder than plumbers lead.  I have to run my RCBS heater on 750° to make it work well.  I cut the sprues before they get hard.  I don’t try to break them off.

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Posted (edited)

Thanks for the replies everybody.  Roto Metals actually does sell a 6% antimony alloy at a hair over $5/lb called hardball alloy for guys who want harder lead bullets.  

They also used to sell a product they called hard alloy (I have about 20 lbs of it) that guys would mix with their pure lead to get various hardness lead for bullet casting.  I didn't see "hard alloy" listed on their website just now, but I may not have known what to look for.  I originally bought mine from them off Amazon.  Don't know if they still sell on Amazon or not.  

Now I need to find a second casting pot to go with my old RCBS Pro Melt.  I want to keep it filed with soft lead, and set up a second for hard lead.  Looks like the only thing close still on the market is either a 220V RCBS 2 or a Lyman MAG 25.  I don't have a 220V circuit back in the corner where my bait making bench is, but I guess I could run one.  

 

Edited by CNC Molds N Stuff
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I have not, but its been unavailable for very long time now.  Running a 220 outlet to the back is not THAT big of a deal.  I had to run outlets for all my other machines and its not a big deal.  Plus, I plan to run a little bit larger hard plastic injection machine sometime in the future back there anyway.  

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You can buy a 1 pound roll of Tin plumbers solder and mix with lead to make it harder . I have mixed it with pure soft lead for hardening bullets I was molding .  Seems to me I was using 9: 1  lead to tin solder ratio.

You can mix it to any hardness you want with a little experimentation .

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Whenever I want to make a harder alloy I use super hard from Rotometals.

Sometimes I also add tin that I get from scrap pewter as well.

But the super hard is a 30% antimony alloy. The nice part of that is that the antimony has already been alloyed in.

Antimony melts somewhere over a thousand degrees. But once alloyed in melts at much lower temperatures.

I have a Cabine tree lead hardness tester and I highly recommend this hardness tester.

So once I know how hard the alloy needs to be, say for a cast bullet, then I guesstimate how much super hard to add and melt it into the pot.

Then I pour a test ingot and test it with my hardness tester.

Then I adjust from there if needed.

This means that every batch that I cast has to be adjusted this way.

Since I cast in a bunch of different bullet calibers and sometimes cast sinkers or jigs in different hardness alloys, this is not that big an issue for me.

But I suppose if you wanted a large volume of all the same alloy it would be a little bit of a pain to do it that way.

Though my largest lead pot holds ~186 lb so I guess I could blend a pretty good volume of alloy in it if need be.

I've never had trouble casting any alloy that I've needed to cast.

They've all filled molds out quite nicely.

So I can't teally give you a specific alloy or ratio.

For me it's about determining and reaching the BHN(Brinnell hardness number) that I am looking for regardless of the exact percentages in that alloy.

 

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