Alloy problems

[Duckhunter]

OK, I got my lead supplies tested and have basically 4 groups of lead and I need to calculate how much of each group I will need to mix to get to a specific alloy. I have one batch that I call lino that is 75.5% lead, 18.8% tin and 7.7% antimony; another batch that is 99.5% Pb, .1% Sb and 0% Sn: another batch that is 95.9 Pb, 3% Sb and 1.1% Sn and finally a batch that is 99.7% Pb, 0.2% Sb and 0.1% Sn. I also have a quantity of SOWW that I did not have tested as I believe these to be 99.5% Pb.

Now the questions! How do I mix these different batches to arrive at Lyman #2 or 20:1 or any other recommended mixture. I have a fairly large pot that I can get more than 20 lbs into. I can add a material from different batches a pound at the time. I don't know where to begin with this process.

I have worked with this in a spreadsheet and can get fairly close but can't seem to get precise in my mixtures. How close is close enough?

[Mitch]

have you tryed the alloy calulator this is what i use.It works very well.I keep some tin and super hard from rotmetals on hand to fine tune things if needed.how close is close enough up to you 1% of sb = about 1 BHN nd 1% of sn =about .3bhn.

here is the link http://castboolits.gunloads.com/show...oy-calculators

[knifemaker]

Also you have to take into consideration as what caliber, rifle or pistol you will be casting for. For most low velocity pistol calibers you can get by with mixing 50% clip on wheel weights with 50% pure lead. No need for Lyman #2. Rifle calibers will require a harder alloy that can be handled by Lyman #2 with a good lube and fit to the bore of the rifle. For years all I used was straight clip on wheel weights with maybe 1-2% tin added for mold fillout and it took care of all my pistol calibers from 38 special to 44 mag and no problems with leading of the bore. Even used it in my 45/70 with a gas check boolit at 1900 fps with no leading and one inch groups at 100 yards.

[kevin c]

Is your first alloy really that high in tin, or did the Sb and Sn percentages get switched?

For me, at least, it's easier to take one base alloy and mix in high concentration additives like pewter, SuperHard or pure lead than it is to mix a couple or more binary or trinary alloys. I think the alloy calculators can tell you whether it's even possible to get what you want from what you have (can't mix up to higher concentration, and hard to change the proportions of constituent metals to exactly what you want unless you have 100% additives).

Your second and fourth batches, along with the SOWW, can be considered close enough to pure. 30% Sb (pure Sb is very difficult to use with our types of equipment), aka SuperHard and pure tin from Rotometals aren't cheap, but a little goes a long way (depending on how much alloy you want to make up), and as a less expensive alternative you can buy scrap lead free solder and pewter at garage sales for the tin.

I'm like you in wanting exact composition alloys, and have been spoiled in that BNE can provide inexpensive analysis that enables that. But it's worth noting that for many, many years folks didn't have content analysis available, and made do with blending stock/base alloy to a desired hardness. And almost always it's the hardness that we worry about anyway, not the composition.

My two cents.

[smithnframe]

That first mix equals 102%.......perhaps your calculations are suspect?

[Duckhunter]

The percentages listed is what I was given, I did not check the math. Apparently the "Linotype" I have is rich in tin. I'm just trying to use what I have on hand. Seeing what I have in my stash, would anyone recommend a combination that would shoot well from my 357 Magnum and 44 Magnum. I would also like to cast some boolits for my 35 caliber rifles; does anyone suggest a mixture from my stash that would work for the 35 Remington, 35/30-30, 357 Maximum or even the 444 Marlin? Thanks for your responses as everything is helpful.

[bmortell]

is the one that's 3% sb 1% sn wheel weights? if so id just mix half and half with pure, add a bit of tin solder like 1% then water drop from the mold or heat treat, and that can do pretty much anything you want.

you have 2 that are basically pure to mix half and half with, if the 3% alloy isn't wheel weights (no arsenic) you could put some magnum shot bb's in it and its basically WW then.

[bumpo628]

You have two alloys that are almost pure lead, so I'd just mix them together and call it pure.

Your 1% tin, 3% antimony alloy is already ready to shoot for most pistol alloys or you could even cut it in half with pure lead as suggested by bmortell above for some applications.

Using your tin-rich alloy, you could make hardball (2% tin, 6% antimony) or Lyman #2 (5% tin, 5% antimony) if you can get some superhard (30% antimony) from rotometals.

Hardball:
Just mix 8.5 lbs pure lead, 1.25 lbs of your alloy, and 2 lbs superhard.

Lyman #2:
Just mix 12 lbs pure lead, 5 lbs of your alloy, and 2 lbs superhard.