Lead and Tin proportions

[UKShootist]

OK, I apologise in advance as I am certain the answer to my question has appeared here many times already. I have looked quite hard but there are so many threads on the subject that each one seems to have some variation or other that doesn't help. The problem is, having purchased a hugely expensive 45/70 405 grain (ordered slightly oversize for a Marlin) mould from Accurate Moulds I have decided it's worth top quality lead which I have purchased. Then I decided to buy some tin, about two and a half pounds, which I now have. All I want to do is to cast lead bullets which I hope will be improved by the addition of some tin. That's all, just lead and tin. I don't want to get too fancy. My question is, what's the best proportion to mix?

TIA.

[runfiverun]

if your doing black powder or a black type speed.
I'd just go with 20-1.
20 lbs of lead and 1 lb of tin.
it has been a 45-70 standard since 18 hundred sumthin

[RickinTN]

Yep Run, that's what I was gonna say. Light it off with about 12grs Unique, or one of my favorites, 35.5 grs IMR3031 and I think there will be smiling faces.
Take care,
Rick

[TexasGrunt]

if your doing black powder or a black type speed.
I'd just go with 20-1.
20 lbs of lead and 1 lb of tin.
it has been a 45-70 standard since 18 hundred sumthin

Ok, I have a question about this. Tin adds very little hardness. More than 2% doesn't help mould fill out. So why is 20-1 or 4.76% tin the standard? That extra 2.76% tin is only going to increase hardness by .8 points.

Why not just go with 2% to help mould fill out and make the expensive tin go 2.5X as far?

[UKShootist]

Thanks for that info chaps. Any more will be very welcome.

[runfiverun]

it might not add BHN but BHN doesn't tell us anything about how an alloy actually acts.
Tin has a long thin matrix which acts like standing a bunch of Christmas wrapper tubes on end.

bonk your little brother once with one and the tube bends and ain't no fun no more.
take 50 of them and put some tape around them and a piece of cardboard on top and you can sleep up there.

antimony adds BHN but it's crystals also breaks down inside a lead alloy under stress and actually allows the lead to slide easier.
add tin to the antimony and it forms a matrix better bonded long chain matrix.
the BHN doesn't change but the internal matrix becomes much stronger and it ties in with the lead better too.

what you hear about additives and what really happens in the absence of other alloy constituents is confusing.
think about those dead soft Hornady swaged 148gr wad cutters.
they actually contain 5% antimony.
a tin alloy is too strong to make them from without ridiculously huge equipment.

[TexasGrunt]

Thanks. I was wondering about that.

[Larry Gibson]

20-1 mix is sufficient for normal BP level loads with the 405 gr bullet. However, Frankford Arsenal found after extensive testing that a 16-1 mix was best for service level 500 gr loads. Elmer Keith also experimented extensively with lead/tin alloys and was using a 10 - 1 alloy initially for his heavy 44 loads. He also settle on a 16-1 alloy though.

I use the 16-1 mix for loads using heavy bullets in numerous rifle cartridges including the 45-70, handgun cartridges and even muzzle loaders when the velocity will be above 1300 fps. In my own 450-400-70 Mauser (Siamese actioned 45-70) I load that alloy in 300, 400 and 500 gr GC'd bullets to 1850 fps.

As mentioned there is more to bullet "hardness" than just the BHN measurement.

Larry Gibson

[quilbilly]

This is all a bit like alchemy, turning lead into gold. When you find the right alloy your rifle/pistol likes and pours well, it is gold. For experimenting at measuring out tin, you might find it worthwhile to buy some lead-free tin splitshot sinkers at your local Wally world. I found adding one size 7 splitshot per pound at a time then pour-and-shoot until you find the sweet spot for what you are shooting to be a fun process. Of course this means you have to spend more time at the range (darn it).

[murf205]

20-1 mix is sufficient for normal BP level loads with the 405 gr bullet. However, Frankford Arsenal found after extensive testing that a 16-1 mix was best for service level 500 gr loads. Elmer Keith also experimented extensively with lead/tin alloys and was using a 10 - 1 alloy initially for his heavy 44 loads. He also settle on a 16-1 alloy though.

I use the 16-1 mix for loads using heavy bullets in numerous rifle cartridges including the 45-70, handgun cartridges and even muzzle loaders when the velocity will be above 1300 fps. In my own 450-400-70 Mauser (Siamese actioned 45-70) I load that alloy in 300, 400 and 500 gr GC'd bullets to 1850 fps.

As mentioned there is more to bullet "hardness" than just the BHN measurement.

Larry Gibson

Larry, if you had a 20-1 mix, how much lino would you need to make it as hard(or behave like) a 16-1 mix? I too, am running a Marlin CB and just scored some pure soft lead, which I have never had the luxury of having before. I have been a WW guy for years, before the tire industry became politically correct! My favorite revolver and rifle(below 1800-1900fps) boolits have been 20-1 WW to tin.

[Chill Wills]

Ok, I have a question about this. Tin adds very little hardness. More than 2% doesn't help mould fill out. So why is 20-1 or 4.76% tin the standard? That extra 2.76% tin is only going to increase hardness by .8 points.

Why not just go with 2% to help mould fill out and make the expensive tin go 2.5X as far?

I think this info comes from some chart somewhere but it is incorrect.
It is true Tin adds hardness in a non-liner fashion and there there is a point of diminishing return.
In other words, the first small amounts increase the hardness most.

Many of us use Pb-Sn and Sb as it is a lot less expensive and cut the tin way down.

Depending on tester and chart, 50 year old published values go something like this.

About is a good word because hardness values are dynamic

pure Pb = 4.5 BHN
30 to 1 = 9
20 to 1 = 10.5
16 to 1 = 11.5
10 to 1 = 12

As you can see, massive amounts of tin return little but up to 30 to 1 is not too bad.

For 45-70 BP or smokeless I like 97- 2 -1 Pb-Sb-Sn and they fill out very well. This gives about 12 bhn
50-50+1%, ww-Pb+tin, is about the same

[murf205]

Sounds great. But the only antimony I have is in some linotype that I have. So is there a formula (about) to get to 11 or 12 BHN with pure Pb? Lino has tin in it so there is no need to add extra tin with the right amount if linotype, I'm thinking.

[Chill Wills]

For every six pounds of lead add one pound of lino and an additional oz of tin.

That will make (about) 97-2-1 Pb-Sb-Sn and should harden to about 11-12 bhn



For one batch in a 20 pound pot with some room at the top try:

15 lbs Pb
2-1/2 lbs lino
one and a half to two ounces tin (1-1/2 to 2 oz not pounds on the tin.)

[murf205]

Thanks, I'll give that a try.

[44man]

Yes, more tin is just cost. I never seen any difference with BP and 1 to 20 or 1 to 30.
Rethink for smokeless, pressure and time to peak is different. With BP you can shoot pure lead. I never needed to add tin for mold fill. I cast pure all the time, more heat.
I never could shoot Elmer's alloy in the .44. Powders and primers have changed since he was here. He did not have WW's either but did shoot harder alloys when he could. Lead and tin was dirt cheap then. There was little choice. Lino was not free until the old printing presses went the way of the Dodo.
Sad to say but the Marlin might need a 20-22 BHN boolit.

[Shiloh]

Higher heat helps fillout. There may be issues with a fractionally smaller boolit from shrinkage.
I add tin as a last resort. There seems to be enough in my scrap to cast decent boolits.

Shiloh

[Green Frog]

When I started in the Schuetzen game I started with an old recipe of 25 parts pure lead to 1 part pure tin (NO antimony.) I used it with BP-equivalent loads for 32-40 up to 45-70 as well as actual BP loads. Never saw a need to change. For most of our rifles antimony seemed to have little or no positive effect and sometimes seemed to harm overall performance. Just my experience and what I've observed for the last 25 or so years, YMMV!

Froggie

[murf205]

Yes, more tin is just cost. I never seen any difference with BP and 1 to 20 or 1 to 30.
Rethink for smokeless, pressure and time to peak is different. With BP you can shoot pure lead. I never needed to add tin for mold fill. I cast pure all the time, more heat.
I never could shoot Elmer's alloy in the .44. Powders and primers have changed since he was here. He did not have WW's either but did shoot harder alloys when he could. Lead and tin was dirt cheap then. There was little choice. Lino was not free until the old printing presses went the way of the Dodo.
Sad to say but the Marlin might need a 20-22 BHN boolit.

I guess I'm fortunate with this Marlin because it shoots straight ww @ 1500 to 1600 fps with no leading what so ever. Unfortunately my ww supply is gone as is my stash. I did find a salvage yard that had a bucket of pure dead soft lead for .50 per lb, so that's where I'm at now.