16:1 cure time?

[jsizemore]

Lead sheet is rarely pure lead. There's usually .1%-1% antimony added to the lead to help with the machining process. Lead is sticky without antimony.

3% tin adds about 1 Bhn so your 6% tin/pewter in your 16:1 alloy will raise your Bhn 2 points.

In the past 4 years of having my pewter tested by BNE I've only had antimony as high as 1%, copper 1.5%, lead 6%, and nothing else other than tin. I usually do batches in excess of 100 lbs. I don't use anything but pieces of pewter marked "pewter". Anything that doesn't have the pewter touchmark I melt and use separately in my buckshot casting.

[Char-Gar]

by the time the hit the table
pretty much cured when you cast them

Yep, that is the truth. Worrying about curing, age hardening and age softening is a waste of time, for none of it makes any practical difference. Save your worry time for world peace of the World's Series.

[Chill Wills]

3% tin adds about 1 Bhn so your 6% tin/pewter in your 16:1 alloy will raise your Bhn 2 points.

I am trying to stay out of these Alloy and Hardness posts but not doing a very good job!

The above is wrong by a wide margin. jsizemore I am not looking to have a fight.

Some things to keep in mind when talking about Pb and Sn, and then maybe Sb with additional trace metals.

-BHN's are dynamic.
-Rules of thumbs are not hard and fast
-Mixing 7bhn Tin into ratios of 4.5bhn Lead is not a linear math problem
-Home BHN testing units are subjective and some people are not very skilled
-Home testing units do not all agree in readout or charts values (which is a bit like buying 10 measuring tapes and some have different -length inches and feet)
-For our purposes (good news) we often have a window or range of hardness we can work in successfully.

Addressing the first post, guessing here, you want a 16-1 Pb-Sn pot of metal to try on a project.

This is a common BPCR metal and often recommended to help hold long unsupported bullet noses from slumping. It is a standard alloy with a standard cited hardness value and sold by Rotometals, John Walters and others.

[Tripplebeards]

So I'm guessing if I remelted my mix and added another 2.3lbs of pewter to my mix it will take me to around 11 BH since 1 lb took my mix up 1.5 points? If so it would be my own custom mix than 16:1. My pewter has a BH of 20.9 so the more I put in the harder it will get?

[Chill Wills]

Tripplebeards, something about what info you have provided so far is in error or at least is not what you think it is because data does not work. (Please don't be offended) It is hard to advise not knowing what really is going on.

Maybe if you would provide some additional info as to what your goal is, we could help.
OR!
If you just want to have a pot full of metal that casts and shoots like 16-1 you need to put aside the metal you have now, and start fresh with real Lead (Pb) and real Tin (Sn). John Walters and Rotometals sells both you can batch yourself or they will sell you pre-mixed ready to go.

Pewter is great and can be found at a great price, but it, in rare cases, is like a Forrest Gump box of chocolates.

[Tripplebeards]

Not affended by any means, just frustrated trying to figure out what went wrong so I can fix it. I'm sure it was my pewter that flawed the mix. The stuff I have melted down has figurines, picture frames, and some stuff stamped as real pewter with touch marks mixed together. I will have to start over again with nothing but touch mark pewter and see what happens. The mixed pewter I have left I'll use for filling out my hollow point molds.

[jsizemore]

I am trying to stay out of these Alloy and Hardness posts but not doing a very good job!

The above is wrong by a wide margin. jsizemore I am not looking to have a fight.

Some things to keep in mind when talking about Pb and Sn, and then maybe Sb with additional trace metals.

-BHN's are dynamic.
-Rules of thumbs are not hard and fast
-Mixing 7bhn Tin into ratios of 4.5bhn Lead is not a linear math problem
-Home BHN testing units are subjective and some people are not very skilled
-Home testing units do not all agree in readout or charts values (which is a bit like buying 10 measuring tapes and some have different -length inches and feet)
-For our purposes (good news) we often have a window or range of hardness we can work in successfully.

Addressing the first post, guessing here, you want a 16-1 Pb-Sn pot of metal to try on a project.

This is a common BPCR metal and often recommended to help hold long unsupported bullet noses from slumping. It is a standard alloy with a standard cited hardness value and sold by Rotometals, John Walters and others.

Appears I am off by 3-4 BHN. Seems tin is quite dynamic.

[Tripplebeards]

I still don't understand how SN(tin) with a BH of 7 mixed 16 to 1 with pure PB(lead) with a BH of 5 is suppose to end up with a BH of 11(16:1 hardness)

Common sense tells me when adding two alloys that don't harden with age the hardest it can get is the greater of the two numbers...Its never going to get harder than 7 BH.


Something is missing in this equation or 16:1 is not made with only pure lead and tin since neither of them are harder than 11 BH to begin with. one of the two alloys would have to be extremely hard like 40 to 50 plus BH and the other would dilute the other down to a softer BH.


Now if I was doing a 16:1 with COWW that were 10.5 BH and adding tin I could see 11 BH from the tin bumping up the BH a hair.

I just don't get it.

I'm going to with the KIS method...keep it simple. I have a ton of COWW ignots that I will just add 2% pewter to for fill out.
I made some the other day. I AC'd them and tested an hour later at 10.5 BH. They may not be as malleable but the hardness is in the ballpark of 16:1 and I'm sure my whitetails won't tell the difference.

[JBinMN]

If ya have not & I think it has been mentioned in this topic or the other one:
http://www.lasc.us/Fryxell_Book_Chap...Metallurgy.htm

Might be a good read for ya. There are others, but That one above is a good place to start...

Another one to help is:
http://www.lasc.us/SuperHard.htm

G'luck! bud.

[Chill Wills]

I still don't understand how SN(tin) with a BH of 7 mixed 16 to 1 with pure PB(lead) with a BH of 5 is suppose to end up with a BH of 11.
Its never going to get harder than 7 BH.
Something is missing in this equation.
I just don't get it.

Okay, here is a different way of thinking about it without getting into the metallurgy. And believe me, I do not have a metallurgy degree either! I just had the same questions as you forty years ago and have been on the quest.

Simple Math is not in play here....
You are not making a mechanical mixture of two (Soft) metals and averaging their hardness, but rather by melting them, you create bonds (structure) between the lead and tin when it returns to solid. How hot, long, time to cool and Pb-Sn ratios control what follows. Post casting storage conditions can effect hardness as well.
BHN - is a measure of yield strength - plastic deformation.

I think at this point if you need more gratification you may need to do some reading about materiel sciences for a baseline. Then track down topics on lead alloys.

[white eagle]

keep in mind bhn only matters when it matters
size.lube and fit to gun are more important than
some fixed number on your alloy
if it hits where you aim and at the distance you want
you are golden

[JonB_in_Glencoe]

I still don't understand how SN(tin) with a BH of 7 mixed 16 to 1 with pure PB(lead) with a BH of 5 is suppose to end up with a BH of 11(16:1 hardness)

Common sense tells me when adding two alloys that don't harden with age the hardest it can get is the greater of the two numbers...Its never going to get harder than 7 BH.


Something is missing in this equation or 16:1 is not made with only pure lead and tin since neither of them are harder than 11 BH to begin with. one of the two alloys would have to be extremely hard like 40 to 50 plus BH and the other would dilute the other down to a softer BH.


Now if I was doing a 16:1 with COWW that were 10.5 BH and adding tin I could see 11 BH from the tin bumping up the BH a hair.

I just don't get it.

I'm going to with the KIS method...keep it simple. I have a ton of COWW ignots that I will just add 2% pewter to for fill out.
I made some the other day. I AC'd them and tested an hour later at 10.5 BH. They may not be as malleable but the hardness is in the ballpark of 16:1 and I'm sure my whitetails won't tell the difference.

I think it's time you forget about the 16:1
COWW is an excellent alloy for Deer.

[gwpercle]

keep in mind bhn only matters when it matters
size.lube and fit to gun are more important than
some fixed number on your alloy
if it hits where you aim and at the distance you want
you are golden

Good advice here !
Take the alloy you have mixed , cast some boolits and see what happens...hardness is way over rated. Fit is so much more important. Lot's of people have fallen into the harder is better hype and it's just horse pucky.
Gary

[Char-Gar]

These kinds of threads that get into the minutia of bullet alloy hardness cause me to grin. I got into casting in the late 50s. We got our bullet metal from an old gunsmith who had several large boxes of 3 lb ingots.

To determine which alloy was correct, we would hit two ingots together. If they went "thud" it was pistol alloy. It it have a "ring" to it, it was rifle alloy. That is all there was to it. You know what, it worked and we produced targets and groups fully as good as all this worry and bother about hardness ever could.

A fortiori (therefore) I have a hard time taking these kinds of threads seriously.

[JWT]

Here is an explanation of the lead-tin phase diagram and what happens as the liquid cools to a solid. http://spaceflight.esa.int/impress/t..._Diagrams.html

As far a the material properties of metal mixtures are concerned, the resulting atomic structure plays a very large part in the final result. The crystalline structure of an alloyed metal is important in determining something like hardness. Think of iron and carbon. Iron is somewhat hard and carbon is generally fairly soft and brittle, but alloyed together you get steel that is harder that either of its components due to the atomic structure of the metal.

[Chill Wills]

These kinds of threads that get into the minutia of bullet alloy hardness cause me to grin.

A fortiori (therefore) I have a hard time taking these kinds of threads seriously.

Okay - each to their own but there is no reason to be condescending. Some people are curious and want to learn. That is what brings many of us here.

[white eagle]

all this talk of 16/1 made me think I need to make up a batch
so I did...
btw I made some 250 gr Keith Boolits and loaded them up with 2400
now there is some kind a fun ehh?

[fredj338]

I just made a 16lb batch. I melted the lead first, added a pound of pewter, mixed for a minute nonstop and fluxed. I made ignots and casted a few test boolits to test BH. How long do I have to wait...it any for 16:1 to cure?

I googled it and the only thing I could find was someone did a test and said it took 18 hours to fully cure?

It doesn't really matter as you are going to remelt & cast. Then your cure time starts. I also suspect the Lee tester, very user specific as to getting repeatable results. I do know that adding true tin to lead does harden it a bit, certainly doesn't soften the alloy.

[K7sparky]

email LEE and they will send you lower BHN data or I found it on LASC

Didn't look much but from a OLD email reply from LEE:
.094" or larger indentation is suitable for black powder gun applications(pure lead). Scope should be perpendicular to sample you are measuring.

[K7sparky]

Hit LASC and read up on what additives are needed to harden lead. There are also plenty of threads on CB addressing the issue.

Short take - toss in a few WW and it will time slightly / quench a lot harden. Diminishing time returns are around 2 days to 1 week depending on how you interpret the curves. Yea I'm a weirdo and look at a month.

Pure lead and pure tin will NOT change BHN with time or water quench.

For us adjudicated hoarders there is a need to look at the long time curves. Hardness over time peaks and then starts dropping.