mixing lead with 50/50 tin /lead???

[usmc0811]

I have 7 piles of pure lead about 15 pounds each of mixed pipe, wheel weight and fishing sinkers. And two other smaller piles of 50/50 tin lead and 40/60 tin /lead . I want to make handgun bullets but dont know how I should mix it all together. How much of the 50/50 should I mix in with the 15 pound piles of straight lead. I have pictures but cant seem to get them on the computer, Ill keep trying.

 

[jmorris]

I have one particular mold I use because I know what weight “certified” lead drops from it.

If it drops heavy, I add Linotype. If it drops light, I add lead.

 

[Hooda Thunkit]

Before you mix things that can't be un-mixed, why not just cast some with the "mixed pipe, wheelweights, and fishing sinkers" ?

If you are shooting handgun, especially low-pressure like 38spl, it may work just fine.

If it doesn't fill out, add an ounce or two of the tin at a time to the pot. The tin is relatively expensive, so if it isn't needed, no sense in using it.

 

[243winxb]

10 lbs pure and 2 lbs 50/50 will make around 12 BHN hardness.

91% pure and 9% tin =11.5 BHN.

Add antimony for harder and larger bullets, as they drop from the mould. Linotype from Rotometels is what i use to up grade an alloys hardness.

Magnum 357, 44 and 9mm will need a BHN of 15. Imo.

 

[forrest r]

A link to a lead alloy calculator. Fill in the blanks and you have your alloy's bhn. It also has standard alloy percentages and bhn's.
http://castboolits.gunloads.com/attachment.php?attachmentid=45784&d=1341560870

Using pencils to test your lead alloys. Cut the wood back on the pencil exposing the lead. Hold the pencil flat/strait up & down and flatten the tip of the pencil lead on a piece of sand paper until the tip is 90* flat and full diameter of the pencil lead. Test your alloy by trying to scrape/gouge the alloy using one of the pencils held at 45* to the alloy. If the pencil scrapes/gouges the alloy then the pencil is harder than the ally. If it doesn't test with harder pencils until you find one that's hard enough to scrape/gouge the alloy.


Using pencils to test alloys is surprisingly accurate.

Typically I make batches of alloy #100 at a time and it usually tests out @ 8/9bhn. That alloy is 12/13bhn when the cast bullets are water dropped. I use that alloy for 90%+ of my revolver/pistol shooting needs. Too much is made out of having the "right" alloy/hard alloy. Anything under 20,000psi I use the air cooled 8/9bhn alloy. Anything over 20,000psi I use the 12/13bhn water dropped alloy. When I get into the long bodied rifle bullets I start using #2 alloy when loading hot loads for the long guns. By hot loads/#2 alloy I mean loads like these 308's.


If it was me I'd use that calculator in the link and use all the pure and enough 50/50 + ww's to make a +/- 9bhn alloy when air cooled. Water dropped will be in the +/- 13bhn range.

 

[Col. Harrumph]

A little algebra is all that's needed. Say you have L pounds of lead and want to know X, the amount (in pounds of course) of 50:50 tin:lead to mix in, to get... let's say you want a 20:1 lead:tin bullet alloy.

1. (L+X/2)/(X/2) = 20/1= 20

(For AOC and the other math-challenged... you know L already because you've weighed your pure lead. L+X/2 is that plus the lead half of X, your 50:50 stuff. The lower X/2 represents the tin half. If you're using some other mix, like 40:60 tin:lead, then the eq. 1 would be (L+0.6X)/(0.4X). Oh and of course 20/1 is just another way of expressing 20:1.)

2. L+X/2 = 20X/2 = 10X

3. L = 10X-X/2 = 9.5X

4. L/9.5 = X

If, say, you want a 40:1 alloy instead, use 40 everywhere you see a 20 above and carry on.

 

[usmc0811]

Today I mixed up the lead by using a 20:1 ratio lead/tin
I made 54 ingots each about 2-3 pounds
I will load some up soon and see how they shoot.

 

[243winxb]

Your blend should be ok, but 5% tin in an alloy is a waste of $ , unless its free or cheap. It is also a poor method of harding a bullet, compared to antimony. Cast bullets using a high % of tin, will soften over time in storage.

Antimony does the harding better and will make a larger diameter bullet, as it drops from the mold.

Molds are requlated to produce a bullet using a certain alloy. Lee is 10-1. Others use #2 Lyman or the "hard ball" blend. https://www.rotometals.com/bullet-casting-alloys/ Holiday Sale now.

Basic Rules for Hardening Lead-

For every 1% additional tin, Brinell hardness increases 0.3.
For every 1% additional antimony, Brinell hardness increases 0.9.
For a simple equation,
Brinell = 8.60 (Antimonial Lead) + ( 0.29 * Tin ) + ( 0.92 * Antimony )

Cast a few and check diameter before making hundreds.

 

[Col. Harrumph]

I think tin is added mainly to improve flow; what hardening it does is usually considered secondary. However I've been wrong before (or so some say).

 

[243winxb]

When casting pure lead for muzzle loaders, more heat is needed for fill out. Hot alloy and mold.

Tin helps bind together antimony/lead alloys. My old Lyman manual said , without tin, the antimony/lead alloy will lead up the barrel. But i didnt find this to be true. Magnum shot with 6% antimony bullets , oven heat treated, did not lead the 44 mag barrel for me.

Tin lowers the melting temperature of the alloy. Better flow.

Results are not always the same when reading the internet. So -imo.

 

[reddog81]

I think tin is added mainly to improve flow; what hardening it does is usually considered secondary. However I've been wrong before (or so some say).

That’s generally correct. I usually don’t add tin into a mix unless I can’t get good fill out with a mold. I picked up some Babbitt that had lots of tin in it and it’s been very helpful for this purpose.