Best & low cost way to convert pure Lead to alloy = BHN 10 ?

[JimGnitecki]

Depending on the dimensions of your superhard ingot, you could go about it a couple of ways.

Throw a piece of plywood across a bathroom scale, zero, and weigh. Then use a c- clamp on the end as a handle and dip into you lead pot incrementally and reweigh until you removed the amount needed.

I've also used a small SS pot sitting atop a piece of plywood on my scale to melt and weight using a Mapp gas torch. Just melted off what I needed from a pig, and dropped that into the already hot lead.

Thank-you, 41 Mag!

Jim G

 

[AJC1]

1......My gunsmith has determined that my specific Pedersoli has a .4563"bore diameter, which of course merits a bullet diameter of at least .4583" for decent obturation. Having already launched the .4595" actual diameter bullet


2....Earlier, I had been firing loads that the load tables indicate would be in the 14,000 to 19,000 maximum psi range. But now that I see the need to keep the velocity higher,

Jim G

On the subject of good/proper barrel fit I think your conflating two different things into one. We cast larger than diameter to force bullet swaging in the barrel, forcing a tight fit. This is good and very helpful for accuracy, and prevents leading/gas cutting. In your situation this is the primary effect helping you get good results. Obturation is the expansion of the base of the bullet to help achieve good fit through pressure. The easiest example is pure lead miniball with a hollow base in a black powder rifle. The skirt is opened against the rifling with pressure and helps with fit. This effect is still minor and requires special lube in high volume to help. Obturation is not really a meaningful factor in your setup.

 

[doubleh]

#4 babbit is used in the oilfield to pour bridles and I experimented with it to harden pure lead. A little dab will do and it was melt a little, cast a few, and check hardness thing until I got to where I could eyeball the amount needed for the amount of pure lead I was melted. Every oilfield supply store keeps it in stock. Other than that I have no idea where to find it. I used scrap melted out of the broken bridle when doing a new one because it was free.

I have also used it with no lead added for plinking with patched round balls. You have to be careful with patch thickness is all. It is so hard shooting a solid surface causes the ball to shatter.

 

[JimGnitecki]

#4 babbit is used in the oilfield to pour bridles and I experimented with it to harden pure lead. A little dab will do and it was melt a little, cast a few, and check hardness thing until I got to where I could eyeball the amount needed for the amount of pure lead I was melted. Every oilfield supply store keeps it in stock. Other than that I have no idea where to find it. I used scrap melted out of the broken bridle when doing a new one because it was free.

I have also used it with no lead added for plinking with patched round balls. You have to be careful with patch thickness is all. It is so hard shooting a solid surface causes the ball to shatter.

I looked it up. #4 Hardware Babbitt is a low melting point speed Babbitt consisting of approximately 85% Lead, 13% Antimony and 2% Tin. It's melting temperature is about 473 F.

This makes it a reasonable substitute for Linotype (which is pretty much no longer commonly available), which used to be 84% Lead, 12% Antimony, and 4% Tin.

Linotype's BHN apparently = 19, so the #4 Babbitt should be very close to the same.

So, yes, this would seem to be a good material to alloy with pure Lead (BHN = 5) in the right ratio to make an alloy with a higher BHN than the pure Lead.

More importantly, unlike Superhard, #4 babbitt has that 2% Tin. That's important because Tin is VERY expensive ($47 per lb in Canada). since you MUST have some Tin in any bullet casting alloy, and since Superhard has NO Tin in it, #4 Babbitt might save a caster a LOT of money - depending upon how costly #4 Babbitt is compared to Superhard.

But, Rotometals also offers #4 Babbitt in 5 lb ingots, same as the Superhard ingot weight. But, they charge $34 US per 5 lb ingot, versus the current $24 US per 5 lb ingot for Superhard.

So, whether using Superhard or #4 Babbitt for alloying with pure Lead makes more sense is going to depend on what BHN a bullet caster is seeking. with the Superhard, you get a lot more hardness per pound, but with the #4 Babbitt, you get the expensive Tin. You'd have to do the math in detail to see which approach gets you where you want to be for less money.

Jim G

 

[gwpercle]

If you already have nearly 50 pounds of pure lead ... then the easiest thing to do is is make a simple mix of
1 / 20 - Tin /Lead (bhn 10) ... or a 1/16 - Tin / Lead (bhn 11) the ratio would need to be bhn tested to get it exact .
At a 1 / 16 Ratio ... 3 pounds of tin + 48 pounds lead = will give you 51 pounds of alloy that should be at least 10 bhn , maybe a tad harder . Always better to be slightly harder , soft lead is easy to add if you want the mix softer .
Shipping charges is always the biggest fly in ordering metals ... but simple tin / lead mixes have worked well for a long time and are easy to melt .
Gary

 

[JimGnitecki]

If you already have nearly 50 pounds of pure lead ... then the easiest thing to do is is make a simple mix of
1 / 20 - Tin /Lead (bhn 10) ... or a 1/16 - Tin / Lead (bhn 11) the ratio would need to be bhn tested to get it exact .
At a 1 / 16 Ratio ... 3 pounds of tin + 48 pounds lead = will give you 51 pounds of alloy that should be at least 10 bhn , maybe a tad harder . Always better to be slightly harder , soft lead is easy to add if you want the mix softer .
Shipping charges is always the biggest fly in ordering metals ... but simple tin / lead mixes have worked well for a long time and are easy to melt .
Gary

What you said is true, BUT 3 lb of Tin would cost me $47/lb x 3 = $141 PLUS shipping which would total to at LEAST $150 Canadian. The Superhard is a less costly solution for me because I already have 0.52 lb of tin left over from the wheelweight alloying.

A combination of 0.5 lb Tin + 5.0 lb of Superhard + 50 lb of pure Lead would give me 55.5 lb of alloy whose percentages would be:
Tin = 0.9%
Antimony = 2.9%
Pure Lead = 96.2%

which should give me a BHN of about 11.6. Very close to typical wheel weight alloy apparently.

That sounds good to me.

Jim G

 

[doubleh]

I have been retired for a lot of years and have no idea of current prices. Back when I was purchasing #4 babbit it was about 4 times the cost of the same sized lead bar. I also can't remember the difference in weight but pure lead is heavier. I do know that bullets turn out nice. I have never had a need for superhard bullets so have no knowledge about it. I have too much brain clutter now as it is.

 

[AJC1]

I have been retired for a lot of years and have no idea of current prices. Back when I was purchasing #4 babbit it was about 4 times the cost of the same sized lead bar. I also can't remember the difference in weight but pure lead is heavier. I do know that bullets turn out nice. I have never had a need for superhard bullets so have no knowledge about it. I have too much brain clutter now as it is.

Superhard is a product, that is like an ingredient in the mix. One could make superhard bullets, but they are so hard and brittle they shatter. They would also be grossly expensive.

 

[Yankee1986]

Superhard is a product, that is like an ingredient in the mix. One could make superhard bullets, but they are so hard and brittle they shatter. They would also be grossly expensive.

I believe this is what they call "frangible". Lol

 

[Pottimus]

MidwayUSA would offer free shipping on orders over $XX, I would often throw in a bar of super hard to reach the free shipping point for my other purchases.
I once got my order, it was a little light, My bar escaped between here and Missouri, sent them a picture of the hole in the box and they made it right. I use super hard and plumbers lead free solder 95/5 to get where I think I need to be.

 

[crstrode]

I think the OP should try some lithium.

 

[Akula69]

To the original poster: If y'all have yard or estate sales up there, it's a great place to find tin plates and serving implements. Most folks turn their noses up at that stuff. E-bay is also a place where folks are looking to dumpo old tin plates for cheap.