Is there a metallurgist in the house?

[badgeredd]

Please refer to this thread:

http://castboolits.gunloads.com/showthread.php?t=146092

I'd really like to know if there is a inorganic chemist or metallurgist in the house. We are experimenting with alloys containing copper which I believe acts kinda like a grain refiner in our boolit alloys. In the thread noted above the subject of adding a known amount of copper to a boolit alloy and there was some response, but nothing definitive. I along with some others are going in circles trying to figure out this one little part of the equation. [smilie=b: I am sure I COULD get a special alloy mixed up from Rotometals, but at this time I am working with some alloys to try and find at least one extremely good alloy one could push much higher than our "normal" three part alloys without investing money into an alloy that isn't favorable.

As a point of interest Lieutenant Townsend Whelen mentioned a boolit alloy of 80% Pb, 10% Sn, 7% Sb, and 3% Cu in a book published in 1909 so I am sure it can be done...but I'm not sure I can do it with my limited resources. Any suggestions?

Edd

[popper]

I researched a little (no, not a chemist or met guy). Cu appears to toughen but soften lead and is very difficult to control. It is used in bearing materials, but not for what you want.

[Guesser]

I just recently came into possession of a large number of belt buckles cast in 2003 from pewter. I melted 5 of them to see the action/reaction. They melted at a low temp, no thermometer, just fast. I cleaned the steel fixtures and the brass? plating out and they are really beautiful Lee 1/2 ingots. I'm told that they are probably 92.5% tin, 6% antimony and 1.5% copper, that being a modern recipe for pewter used in this type of product. I'm thinking they will make a fine alloy for casting boolits, am I right??

[badgeredd]

I just recently came into possession of a large number of belt buckles cast in 2003 from pewter. I melted 5 of them to see the action/reaction. They melted at a low temp, no thermometer, just fast. I cleaned the steel fixtures and the brass? plating out and they are really beautiful Lee 1/2 ingots. I'm told that they are probably 92.5% tin, 6% antimony and 1.5% copper, that being a modern recipe for pewter used in this type of product. I'm thinking they will make a fine alloy for casting boolits, am I right??

IMHO..yes... the alloy you have when alloyed correctly should give you an excellent boolit material. I've been playing around with #2 babbit and pure lead and COWW along with linotype to get some different alloys. Your pewter is higher in tin and lower in copper than the babbit I am using.

Edd

[badgeredd]

I researched a little (no, not a chemist or met guy). Cu appears to toughen but soften lead and is very difficult to control. It is used in bearing materials, but not for what you want.

I am thinking that the amount of tin in an alloy influences the alloying properties of the copper. I may be completely wrong but that is why I need a metallurgist or chemist to help me out here. I will tell you I have found the copper definitely affects the ability of an alloy to be hardened without brittleness.

Edd

[runfiverun]

the tin does hold the copper in suspension.
it figure 3 parts tin to one part copper.
the amount that whelen shows is about the max that leftiye and myself was able to get into an alloy.
10% tin and 3% copper you need to keep the antimony up there with the tin or have none at all.
it will keep the copper soluble but not bind with it.
and it will still tear from the antimony chain and cause soft spots in the boolits.
for this eason i started making my copper alloys from linotype and tin and cutting it with pure lead.
then using sulpher for my grain modifyer.

i am not a metallurgist those are just my findings.

[badgeredd]

the tin does hold the copper in suspension.
it figure 3 parts tin to one part copper.
the amount that whelen shows is about the max that leftiye and myself was able to get into an alloy.
10% tin and 3% copper you need to keep the antimony up there with the tin or have none at all.
it will keep the copper soluble but not bind with it.
and it will still tear from the antimony chain and cause soft spots in the boolits.
for this eason i started making my copper alloys from linotype and tin and cutting it with pure lead.
then using sulpher for my grain modifyer.

i am not a metallurgist those are just my findings.

Thanks RFR, I am slowly getting the idea of how it all fits together. I wish the boss I had MANY years ago were still with us. He'd be a lot of help in the whole scheme of things.

Can you expand of the use of sulfur?

Edd

Edd

[popper]

sulfur is a grain refiner, like they say. It actually links into the lattice, forming discontinuities that strengthen the alloy. I've had trouble with remelting the CBs, sulfur seems to come back out. researchers appear to cook it a long time to get a really good mix.

[BattleRife]

http://www.crct.polymtl.ca/fact/Documentation/BINARY/Cu-Pb.jpg

Looking at the phase diagram for copper-lead, the solubility is quite good, up to 13% copper can be dissolved and the melt remains homogeneous.

There are two features I see here that could contribute to strengthening. First is the very steep slope of the liquidus line at the right side of the diagram. This suggests that at low concentrations of copper, say around 2%, even very small changes in Cu concentration will make a dramatic change in the temperature at which the first solid crystals appear. I've never heard of this, but it seems like this situation could indeed promote grain refinement as local areas of the melt that were very slightly elevated in copper could begin to from seed crystals in advance of the bulk of the melt.

A more interesting feature is that above the solidus line the melt will be mushy, consisting of liquid alloy and an FCC (face-centered cubic crystal structure) solid. However, as soon as we get below the solidus line the equilibrium is a mix of FCC and HCP (hexagonal close packed) crystal solids. This means that some of the previously formed FCC solids must transition to HCP solids, a shift that is no doubt going to cause considerable strain of the crystal lattice and probably a small volume change. Now this sounds like the type of mechanism that would cause strengthening. It also corresponds nicely with the observation by 303guy in that other thread that he could measure the hardness increase over the course of an hour in copper-bearing alloys. It is very possible that the FCC to HCP tranformation was occurring over that hour, with the associated increase in lattice strain resulting in increased hardness.

[runfiverun]

he's saying the copper affects the alloy stream from the pot.
and that it hardens the outside of the boolit through a chemistry change.

something like waterdropping a hot boolit hardens more from the antimony.
popper has the sulpher thing pretty good, it acts like arsenic.

it does have a tandency to want to come back out on a re-melt, but i have no problems with that.
i usually find very little if any of these boolits, as i run them pretty fast down range.
i don't have much use for 3% copper though, i usually keep it down under 1%.
casting becomes pretty difficult at the cool alloy temps i like to run, if i get the copper up.

[tonyjones]

BattleRifle,

Is the solubility of sulphur-lead as good as that of copper-lead? When sulphur has been used as an alloying element with certain steel alloys problems have been reported concerning the formation of occlusions that can cause machining problems. Think 416R stainless steel as used in rifle barrels. I'm wondering how easy it is to obtain a homogeneous lead alloy with sulphur in the mix.

Thanks and regards,

Tony

[badgeredd]

Thank guys.

RFR, I'm in agreement with the 1% copper content for our purposes. I still haven't found a relatively easy way to add copper in known amounts to a mix. Other than using babbit for a copper source there seems to be little information available to casters like ourselves.

I've considered getting a custom mix made up to use in alloying but haven't as yet checked into the pricing. Other than babbit alloys with very low lead content and high tin content, there doesn't seem to be a readily available alloy. It seems that if one could get a "component metal" that had a relatively high copper content, he could then add it to our traditional 3 part mixes to get a pretty good alloy for high speed cast boolit loads that could push the 50.000PSI range. Also it is my belief that the boolit would be less affected by the high rpms some rifles encounter at relatively low pressures. It seems to me that we are dealing with a mtter of alloy strength in both areas.

Edd

[runfiverun]

we are and that is why i was/am using it.

i like to melt down those plated boolits [and copper coated 22's] and let the alloy sit for a bit.
you'll see the copper on top.
i add 3% tin to the mix and flux. then skim everything off the top.
i use this as a 1% copper additive for other alloys.
knowing that the tin will pull in only so much of the copper to the alloy.
there are other ways to add it to the alloy but this one works for me, and all i need to do is sort through range scrap to get it.
i doubt the numbers are perfect but it is as close as i can get at home, and it's repeatable.

[Larry Gibson]

Whelen specifically says; "Ideal Bullet Metal, procurable from the Ideal Manufacturing Company, is composed of 80 parts lead, 7 parts antimony, and 3 parts copper by weight. It is the most satisfying alloy, as if is tough enough to stand the 10-inch twist of the rifling, and has a higher melting point than a plain lead and tin alloy." So obviously over 100 years ago they had no problems casting bullets with such(?). Thus I would think we could do the same these days?

Badgeredd and I are specifically interested in how one may get the 3% tin into the alloy? Ok if sulfer is grain refiner then how is it added to the mix. Some useful into such as;

Where to get the sulfer?
What kind/type of sulfer?
How is it added to the alloy (before the additional copper, after, when?)?

Where to get the copper?
What kind/type of copper (solid, powder, etc?)?

Temperature to mix the alloy at?
Same temperature to cast?

WQ or AC?

I have cast one batch of 94 pb, 3 Sn, 3 Sb and .1 Cu with a trace of As. It melted and fluxed correctly at 750 degrees which is what I cast at. The bullets were WQ'd out of the mould. I had a very large % of rejects due to non fill out. The BHN was 14 about 1 hours after casting. The BHN was 17 - 18 at 24 hours and after 7 days has stabilised at 23 - 26 BHN.

I'll be testing this bullet at 2650 - 2700 fps next week out of my Palma .308W. If all goes well there I will change to a 10" twist '06 and push that bullet to HV to see how high a velocity and RPM can be pushed with accuracy.

Edd and I are really interested in increasing the Cu content to what the old Ideal alloy was. We need some specific know how on how to do it?

Larry Gibson

[blackthorn]

From my "saved" stuff (don't recall where I got it):



Phosphorus/copper can be alloyed with molten lead in the following way: Combine one or two 0.050 x 1/8” x 18” phosphorus-copper brazing rods to each pound of lead WW alloy. Use a propane torch to heat a spot on top of the melt until the first signs of red appear. Maintain the red spot while stirring the rods of phos-copper into the red spot. THIS MUST BE DONE OUTSIDE AND YOU MUST NOT INHALE THE FUMES because of the extremely toxic lead vapour produced by the abnormally high temperature required to bring the lead to a temperature that will allow the phos-copper to blend in. Once the process is complete, the new alloy will melt and cast at normal temperatures.

[blackthorn]

I do not know if the post I made on putting copper into lead will work or not, I never got around to trying it (yet).

[.357MAN]

From my "saved" stuff (don't recall where I got it):



Phosphorus/copper can be alloyed with molten lead in the following way: Combine one or two 0.050 x 1/8” x 18” phosphorus-copper brazing rods to each pound of lead WW alloy. Use a propane torch to heat a spot on top of the melt until the first signs of red appear. Maintain the red spot while stirring the rods of phos-copper into the red spot. THIS MUST BE DONE OUTSIDE AND YOU MUST NOT INHALE THE FUMES because of the extremely toxic lead vapour produced by the abnormally high temperature required to bring the lead to a temperature that will allow the phos-copper to blend in. Once the process is complete, the new alloy will melt and cast at normal temperatures.

What is the Phosphorus for? Is Phosphorus required for alloying?

[popper]

Lawn sulfur powder. ~$7 @ HW store. I just filled my small ladle with it and pushed it under the melt(650F). I got a big hard ball floating to the top. I use a putty knife to stir and could chop it up until it dissolved. I let it cook for an hour - I read in some research that it takes a while to get it to uniformly replace molecules in the lattice structure. It also creates all the PbSox and Sox compounds. Commercial sulfuric acid is a byproduct of smelting Pb ore. Do NOT use copper sulphate! All the research I can find on adding Cu indicates it doesn't work like S or As; it modifies ductility but that shows up on a hardness tester. In any case it should help make strong bullets. Most of my Pb studies are research articles from battery grid studies, yes, they use stuff we don't want to play with. I think the solubility of Cu in Pb is < 1% it probably combines with the Sn. I did twist some commercial (BHN18) and my Pb/As/S bullets. the shear pattern was really different. Theirs sheared level and slightly rough while mine(WD) had a fish scale pattern surrounding a sharp pile of darker material. I am assuming that means the CB didn't get hardened completely, the water wasn't cold enough.
Table (2): Mechanical and electrical properties of melt-spun alloys.
Composition
Dynamic Young's Modulus Y (GPa)
Hardness,VHN

Pb-5wt.%Sn 20.05 6.5
Pb-5wt%Sn-0.5wt%Sb 26.22 6.2
Pb-5wt%Sn-0.5wt%Zn 16.8 5.6
Pb-5wt%Sn-0.5wt%Cu 24.5 4.15
Pb-5wt%Sn-0.5wt%Ag 14.05 5.12
This table didn't come out right but the Young's modulus is first value, hardness (not BHN) is second. Cu doesn't harden much but strengthens.
Cu is soluble in Sn,Sb,Ag,As(10^5/10^6) not in lead(10^2/10^6).

[BattleRife]

BattleRifle,

Is the solubility of sulphur-lead as good as that of copper-lead? When sulphur has been used as an alloying element with certain steel alloys problems have been reported concerning the formation of occlusions that can cause machining problems. Think 416R stainless steel as used in rifle barrels. I'm wondering how easy it is to obtain a homogeneous lead alloy with sulphur in the mix.

Thanks and regards,

Tony

The reaction of sulphur in lead is very different. As you can see, there is no solubility, instead you get a bath of liquid with lead sulphide, which hardens to solid lead and lead sulphide. The two react to form the sulphide, but there is no alloying of the sulphur with the lead:
http://www.crct.polymtl.ca/fact/documentation/FSlead/Pb-S.jpg


The behaviour of sulphur in iron, which relates to your question about steel, is similar, though more complicated. At low concentrations of sulphur, the liquid hardens to form sulphide (on the diagram as (Fe,Mn)S_P) plus a BCC phase. That BCC phase is sulphur dissolved in iron, but the more important phase is the iron sulphide, which will not alloy, but instead resides in the final solid as islands:
http://www.crct.polymtl.ca/fact/documentation/FSstel/Fe-S.jpg

The answer to your question is that you essentially cannot get a homogeneous lead alloy if it has sulphur in it. The sulphur is happy to exist only as lead sulphide, and it will not dissolve at all into the lead.

[badgeredd]

The reaction of sulphur in lead is very different. As you can see, there is no solubility, instead you get a bath of liquid with lead sulphide, which hardens to solid lead and lead sulphide. The two react to form the sulphide, but there is no alloying of the sulphur with the lead:

The answer to your question is that you essentially cannot get a homogeneous lead alloy if it has sulphur in it. The sulphur is happy to exist only as lead sulphide, and it will not dissolve at all into the lead.

For this reason I'd appreciate if we return to the original question...how can copper in known amounts be successfully added to our boolit alloy?

I am of the opinion the best and easiest way to add copper to our melt in known quantities is to use a copper bearing babbit...but I had hoped I was mistaking and someone would add their knowledge to the thread.

Edd

[303Guy]

I've dissolved copper by tinning a piece of copper then submerging it into a tin containing lead alloy at fairly high temperature - like 550°C.

[badgeredd]

Thanks 303Guy. It seems there isn't a really convenient way to add copper as I had hoped so I'll be trying your method in the near future. If I could figure a way to get pure copper oxide, I'd try putting some of it into a mix to see if it would assimilate completely. Of course I'd have to figure out a way to calculate the actually amount of copper one would be adding to his mix.

Edd

[popper]

badgeredd - get Sn/Cu solder at the HW store. Melts in easily. I doubt that Lieutenant Townsend Whelen knew exactly what he really had in his melt in 1909, he just didn't have the equipment to know. The chart I showed is from a basic alloy study, not someone's receipy so I assume the %s are max. It shows Cu isn't any better than other stuff we use.

[rockrat]

I had Rotometals make me an alloy, IIRC, comparable to #2 alloy, but replaced 3% of the lead with copper, so, 87/5/5/3. Upon reflection, it may have been 92/5/3 and I just added tin when I made my blend, which came out to the 88.5/5/5/1.5. To get a decent price, IIRC, I had to get at least 200 lbs.

It appears to be harder than water cooled #2 and has a bit of a different sound when I dropped a boolit on the floor. Melt was a bit "mushy" on the top of the melt, so I upped the temp to 725 degrees, and that worked.

I think that there is still a bit more copper than I need, I think 1% will be enough.

I don't know if you really need the CU alloy for your 50K loads. I was shooting my 357max Ruger #1 last year and was pushing a 200gr boolit pretty hard. Lets say, that when I upped the charge to see what it would do, I lost a few cases because of expanding the primer pocket!!!! Pulled the rest of the boolits, but didn't have any leading in the bore of the rifle, and accuracy was good. It was water cooled #2 alloy, sized .360". I wouldn't want to use those loads in my 357max Ruger SRM, but the Rifle digests the probably 50K loads with ease. 200gr @2,200fps

I was trying the copper alloys in my 50cal. No matter how hard the alloy was, when the throat is so large and the leade is so long, gas cutting reared its ugly head above 2200fps with any alloy. The barrel needs to be set back and chamber re-cut.

Might have to cast some of the 311440 or 314008 boolits with the copper alloy and see what I can do with them in the '06:)

[Rangefinder]

All right, dammmmmmit--you clowns have just given THIS clown an idea. I'll test my theory later this morning. If it works the way I think it should, I'll post the whole thing and what I find. :D Dammmn-you all to the firey underworld of boolit casting for sparking yet another experiment into my head! This could be fun :D

[Larry Gibson]

badgeredd - get Sn/Cu solder at the HW store. Melts in easily. I doubt that Lieutenant Townsend Whelen knew exactly what he really had in his melt in 1909, he just didn't have the equipment to know. The chart I showed is from a basic alloy study, not someone's receipy so I assume the %s are max. It shows Cu isn't any better than other stuff we use.

The alloy wasn't Whelen's alloy. It was what could be purchased from the Ideal Manufacturing Company, the predecessor to Lyman. They would have known what was in the alloy as they would have either mixed the alloy or had it made for them considering they also cast sold the cast bullets along with reloading equipment, moulds and sights back then.

Larry Gibson

[badgeredd]

I had Rotometals make me an alloy, IIRC, comparable to #2 alloy, but replaced 3% of the lead with copper, so, 87/5/5/3. Upon reflection, it may have been 92/5/3 and I just added tin when I made my blend, which came out to the 88.5/5/5/1.5. To get a decent price, IIRC, I had to get at least 200 lbs.

It appears to be harder than water cooled #2 and has a bit of a different sound when I dropped a boolit on the floor. Melt was a bit "mushy" on the top of the melt, so I upped the temp to 725 degrees, and that worked.

I think that there is still a bit more copper than I need, I think 1% will be enough.

I don't know if you really need the CU alloy for your 50K loads. I was shooting my 357max Ruger #1 last year and was pushing a 200gr boolit pretty hard. Lets say, that when I upped the charge to see what it would do, I lost a few cases because of expanding the primer pocket!!!! Pulled the rest of the boolits, but didn't have any leading in the bore of the rifle, and accuracy was good. It was water cooled #2 alloy, sized .360". I wouldn't want to use those loads in my 357max Ruger SRM, but the Rifle digests the probably 50K loads with ease. 200gr @2,200fps

I was trying the copper alloys in my 50cal. No matter how hard the alloy was, when the throat is so large and the leade is so long, gas cutting reared its ugly head above 2200fps with any alloy. The barrel needs to be set back and chamber re-cut.

Might have to cast some of the 311440 or 314008 boolits with the copper alloy and see what I can do with them in the '06:)

It sounds like you are on the same track as I am. My original question was posed because the "custom" alloys are a bit pricey to put it mildly. I'm in agreement to a point that 1% copper may well be the most copper one will really benefit from but until I have tried 1 1/2%, 2%, 2 1/2% and 3%, I can't honestly say. It does appear that 3% is pretty much the upper limit of copper concentration.

What I am looking for can well be made if one purchases a custom alloy to blend with COWW, pure lead, babbit, and linotype thus keeping the cost down somewhat for a stronger alloy. I haven't any intention of making this a primary alloy, but I think it would be nice to find a reasonably affordable alloy that was repeatable to use in a select number of rifles. I have pushed some cast boolits to the 45,000+ psi range with good success and believe that 50,000 psi is achievable WITH accuracy. In my mind it comes down to alloy strength if one is going to be able to push cast boolits to the upper limits. At the cost of jacketed bullets, one can experiment a bit with a stronger alloy and still save a few nickels left over which ultimately would allow us to shoot more for our dollars.

Thanks to all that have made useful suggestions. I think this thread has pretty much run its course and I'll continue to experiment with alloys to try to find the upper limits by using a stronger affordable alloy.

Edd

[popper]

Larry - not knocking the people in 1909 at all, they just didn't have the equipment to know really what the compounds they made really were. Maybe some was in the lattice, some was pure globs, globs of Sn/Cu, etc. Rockrat - did you try the #2 WD with As or S? I got interested in adding Cu till I did some reading and as the results I posted, As or S do the job at less $ and easier. I'm going by youngs modulus which is the actual molecular material strength. BHN is an indicator of strength by a simple test. badgeredd - now if you get some cadmium and bismuth to add, you will get stronger alloy.

[Rangefinder]

All right---had an idea, but I'm not sure it was a good one yet.

The plan was to melt a pound of WW, cast a coin to test, then add 1% by weight of copper sulfide. I brought the temp WAY up, powdered the copper sulfide, blended it with a little bees wax to make a fluxing paste, and stirred it in. After cooking for about 10 minutes the melt developed a dark gray powder skim. after pulling that off, the melt always had a dull white surface. So I cast a test coin from that. After air-cooling both, I dimpled them. Nothing too scientific, and I don't own a hardness tester. I simply filed a flat spot of both, put them in a vice with a ball bearing between, and gave 'em a squeeze. Result: the dimples measured identical.

In theory, the idea has potential. I'll have to play with this one a little to see if I can come up with a better way to combine the copper rather than what seems like just fluxing it right back out.

[badgeredd]

Larry - not knocking the people in 1909 at all, they just didn't have the equipment to know really what the compounds they made really were. Maybe some was in the lattice, some was pure globs, globs of Sn/Cu, etc. Rockrat - did you try the #2 WD with As or S? I got interested in adding Cu till I did some reading and as the results I posted, As or S do the job at less $ and easier. I'm going by youngs modulus which is the actual molecular material strength. BHN is an indicator of strength by a simple test. badgeredd - now if you get some cadmium and bismuth to add, you will get stronger alloy.

Cadmium isn't caster friendly. It gives off some dangerous gases.

Me thinks you highly underestimate the old school alloying of metals. You're correct they didn't have the technology we have available to us now, but some pretty huge developments were made in firearms and metal alloying in the first quarter of the 20th century. Case in point, nickel steel. No electro-spectrographs to analyze the end product but they did have good old chemistry. As a tool maker (tool designer and tooling engineer), I have a lot of respect for the products that were turned out and the individuals that did a lot of research in industry a hundred years ago. We are still using formulas for steel (and other metals) alloys that were developed in the early 20th century because they worked. Apparently they were pretty darned consistent in their chemical make-up.

Edd

[blackthorn]

.357man--- I really can't answer you with respect to the phosporus, the recipe I posted was a simple cut and paste from somewhere in the past. I tend to save a lot of stuff that catches my interest and that was one of them.

[Larry Gibson]

badgeredd - get Sn/Cu solder at the HW store. Melts in easily. I doubt that Lieutenant Townsend Whelen knew exactly what he really had in his melt in 1909, he just didn't have the equipment to know. The chart I showed is from a basic alloy study, not someone's receipy so I assume the %s are max. It shows Cu isn't any better than other stuff we use.

I'm probably going to try popper's Sn/Cu solder idea. Have to work the figures though to get 3% copper in the alloy.

Larry Gibson

[popper]

badgeredd I agree on the old stuff, Chevy had a v-8 ohv alum engine in 1917, etc. I'm just tryin to (in my simple mind) separate the truth and fiction. If Cu will help make better bullets (and we know WHY) at reasonable method and $, I'll add it. Period.

[badgeredd]

All right---had an idea, but I'm not sure it was a good one yet.

The plan was to melt a pound of WW, cast a coin to test, then add 1% by weight of copper sulfide. I brought the temp WAY up, powdered the copper sulfide, blended it with a little bees wax to make a fluxing paste, and stirred it in. After cooking for about 10 minutes the melt developed a dark gray powder skim. after pulling that off, the melt always had a dull white surface. So I cast a test coin from that. After air-cooling both, I dimpled them. Nothing too scientific, and I don't own a hardness tester. I simply filed a flat spot of both, put them in a vice with a ball bearing between, and gave 'em a squeeze. Result: the dimples measured identical.

In theory, the idea has potential. I'll have to play with this one a little to see if I can come up with a better way to combine the copper rather than what seems like just fluxing it right back out.

From what I have been able to glean from several sources, one needs at least a 3:1 ration of tin to copper to alloy it properly into a lead alloy. I am thinking a guy could add the copper to tin more easily and then alloy the tin mix with his lead. Just a thought...but it seems one then would not have to super heat lead to get the copper into his melt. I have a high tin babbit supply and am thinking about trying that. I can see where this could go cost wise if one wasn't careful. As Larry Gibson can tell you, the addition of copper and tin in the form of babbit makes your alloy act differently when water dropped. It also affect the strength of the boolit alloy quite favorably.

Edd

[BattleRife]

I could figure a way to get pure copper oxide, I'd try putting some of it into a mix to see if it would assimilate completely.
Edd



The plan was to melt a pound of WW, cast a coin to test, then add 1% by weight of copper sulfide.

I wouldn't expect either of these methods to work. Thermodynamically speaking, the copper would strongly prefer to remain as a compound, and it will take a powerful reducing agent to dissociate the copper from the oxygen/sulphur. There is nothing in a pot of wheel weights that would even approach that kind of reducing power.

[badgeredd]

I wouldn't expect either of these methods to work. Thermodynamically speaking, the copper would strongly prefer to remain as a compound, and it will take a powerful reducing agent to dissociate the copper from the oxygen/sulphur. There is nothing in a pot of wheel weights that would even approach that kind of reducing power.

Any suggestions?

Edd

[Michael J. Spangler]

side track

does anyone know if cryogenic treatment has any affect on lead or heat treated lead alloys?

[303Guy]

I did find that too much copper in my particular alloy made casting difficult. I got the idea from somewhere that optimum copper content was a fraction of a percent. What ever the alloy was it did seem to hold together well under impact, was fairly ductile and yet quite strong. No numbers to define it's qualities unfortunately. It did have higher antimony than my current alloy. I had the impression that the copper reduced the brittleness from antimony. I would think that was from the grain refinement effects.

[popper]

Rangefinder - that is the scientific way of making the measurement. Their test machine also includes time in the equation to account for cold flow and other funny effects.
303guy - I suspect the cast-ability problem arises as the Cu takes the Sn out of Sn/Sb, Sn and Pb. From what I can find, Cu grain refining is minimal, but it may be that the Cu/Sn in the melt adds strength. At $25/lb for Cu/Sn solder, I need some justification for using it. This makes an interesting read http://144.206.159.178/ft/464/586329/12469242.pdf. This is the range where we melt stuff. I don't know the mechanical properties of the compounds.

[badgeredd]

Rangefinder - that is the scientific way of making the measurement. Their test machine also includes time in the equation to account for cold flow and other funny effects.
303guy - I suspect the cast-ability problem arises as the Cu takes the Sn out of Sn/Sb, Sn and Pb. From what I can find, Cu grain refining is minimal, but it may be that the Cu/Sn in the melt adds strength. At $25/lb for Cu/Sn solder, I need some justification for using it. This makes an interesting read http://144.206.159.178/ft/464/586329/12469242.pdf. This is the range where we melt stuff. I don't know the mechanical properties of the compounds.

What is the copper content % for the solder you're talking about? Rotometals has tin based babbit that contains as much as 7.5-8.5% copper and apparently is priced significantly lower than the solder. Part of the problem I see with using a solder is in trying to keep the tin content of a mix in somewhat of a balance with the antimony and copper.

303guy, I suspect the 3:1 tin/copper ration has an affect on the ability of the copper to be taken into the mix in a more homogeneous way, BTW, I have to go back through the stuff I've read in the last month to find where I came up with the 3:1 Ratio. Also note how high the copper content in the babbit alloys at Rotometals can be pushed. Again I believe the tin content is the answer to getting a higher copper content. BUT that is just a guess since I'm not trained in the metallurgy field.

Edd

[rhead]

You could take a batch of your base alloy, (lynotype, lyman #2, Wheelweights pluse 5% tin ore whatever you choose) SATURATE this alloy with copper at a known temp (800*F, 900*F whatever you can reliably reproduce.)
Then make a series of blends to cast up trial batches of boolets at known ratios. (100% to 0% saturated) Check the boolits for performance. Probably one of these batches will out perform the others. Example 40% of the saturation point for your base alloy.

If you really have a need to know the copper content of the alloy you can have a sample checked by a lab. But once you get this number what do you plan to do with it beside report it? A reproducible recipe is what is needed.

Building an alloy from scratch on a small scale would be much harder to control.

[Larry Gibson]

You could take a batch of your base alloy, (lynotype, lyman #2, Wheelweights pluse 5% tin ore whatever you choose) SATURATE this alloy with copper at a known temp (800*F, 900*F whatever you can reliably reproduce.)
Then make a series of blends to cast up trial batches of boolets at known ratios. (100% to 0% saturated) Check the boolits for performance. Probably one of these batches will out perform the others. Example 40% of the saturation point for your base alloy.

If you really have a need to know the copper content of the alloy you can have a sample checked by a lab. But once you get this number what do you plan to do with it beside report it? A reproducible recipe is what is needed.

Building an alloy from scratch on a small scale would be much harder to control.

Understand all that expcept one thing: The question is; what is the procedure to "saturate" the copper into the alloy. What kind of copper is needed and how/what is the process, exactly, to blend/saturate it into the alloy?

Larry Gibson

[offshore44]

I have been following this thread with great interest.

It's too bad that the folks over at Oregon Trail Bullets won't pitch in a little expertise and advice on this subject.

Here is a link to a pdf on their web site that mentions the alloy content of their bullets. Link: http://www.laser-cast.com/files/LM_What_Makes_These_So_Accurate.pdf

The alloy is said to contain silver, copper, bismuth and other minor constituents and gives high level reasons for why it works the way it does.

I have a "scrap lead alloy" bucket that I throw all the misc. lead into. Awhile back I purchased a batch of Oregon Trail Laser cast bullets that the meplat was too large to reliably feed through one of my bolt action rifles. Into the bucket it went. When I went through and tested the hardness of the alloy after making ingots, I discovered that it had a BHN of 18.5 - 19. This developed after a few days of sitting around under the bench. The hardness really starts ramping up after a couple of hours after being cast. Not a lot of time - temperature - hardness data here...I just decided to cast a few 8mm boolits from this MX alloy in my Saeco mold to play with harder paper patched boolits for the Mauser. Sizing down to 0.314" from 0.324" was difficult, but possible about 45 minutes after casting. Sizing down the same amount two hours after casting was not a happenin' thing. After trying several sizing lubes and two different presses, I gave up. Kept sticking boolits in the sizing die right at the start of the driving bands.

I had to run the pot up to 850° to 875°, and get the mold much hotter than usual to cast good boolits. Once I did that though, the boolits dropped out of the mold perfectly. The reject rate was extremely low once I got the process figured out. The weight was uniform within one grain if the rejects are excluded. The dimensions were the same across the batch within the limits of my measuring instruments. Size and weight wise the boolits come out of the mold just like Lyman #2 alloy, just harder and more uniform.

When the alloy was melting, it formed a slush, a really ugly slush, for a short period of time before transforming into that nice silvery liquid we all use and love. I had to cast fast and hot to get good fill out - especially the bases. The only way to get a good base fill out was to let the molten stream pour into the sprue hole until it was running over the side of the mold. The sprues probably had about half again as much metal in them as the boolits did; without exaggeration. When the sprues froze, they first turned a silvery grey color while still liquid and then froze all at once. I suspect that the boolit in the mold did a similar thing.

I'm going to make some more of these today, just for giggles, and load them up as gas checked. Push the pressure / velocity a little and see what happens. I'm betting that they shoot really well in 2,300 fps range that I'm looking for with the Mauser.

It would be nice to duplicate this alloy without having to melt down OT Laser Cast boolits to do it!

[rhead]

Understand all that expcept one thing: The question is; what is the procedure to "saturate" the copper into the alloy. What kind of copper is needed and how/what is the process, exactly, to blend/saturate it into the alloy?

Larry Gibson

For a 20 p0und pot I would start with 16 or 17 pounds of alloy and one pound of copper fileings (lots of surface area) and as much crushed charcoal or sawdust as it will hold to act as an oxygen barrier. Crank the pot up to max and add more oxygeb barrier and remove ashes as needed. Stir occasionally to keep fresh alloy in contact with the copper that is floating on top. Start this early in the morning. It will take several hours. You cannot realy get to the saturation point you can just approach it. You do not have to be there the whole time stirring. It shouldnt take many times until you get a pretty good idea of how often you will need to refresh the oxygen barrier. After 8 hours or so you will be close enough to the saturation point that it will not matter to a blend made out of it. Remove the ashes and any remaining copper. If there is no copper remaining the solution was not saturated. Add more copper and try again. If there is copper remaining the blend is saturated. Keep notes on the amounts and settings so you can reproduce the blend.

[popper]

Sn/Cu solder is 95/5. That means you should use a no Sn alloy to start. I suspect one would need to skim the tin from the top to reduce the % and save it for later use. The link I posted shows EM pics of the actual alloy and is quite interesting (just skim the article and look at pics). The Cu combines with the Sb and takes a lot of cooking to get it into the melt properly. I had the same results with Sulfur. Labs cook it for 72 hours to make sure the melt is uniform. I'm still reading to see if I can find the mechanical characteristics of adding Cu. Companies with proprietary info aren't going to make much public - $$. As I stated earlier, young's modulus is the tensile/compressive strength of a material. The shear modulus is also important, as the CB is twisted at the nose before the base. Just read all of LC article and some of sounds like marketing spin. I suspect the bismuth is the key element. Yes, you do want sudden 'freezing' of the alloy for best bullets (i.e. ice dropping).

[popper]

Larry - found some info on Cu alloys. Found a good article with young's, shear, bulk and poissons numbers but they want $50 to read it. Anyway, Castin alloy Sn96/Ag 2.5/Cu .8 Sb .5 has pretty food strength 217C melt but Pb97/Ag1.5/Sn1 is 95% as strong @ 300 C. Also, excessive Cu in mix forms Cu6Sn5 which is VERY brittle.

[Larry Gibson]

rhead & popper

Alright, now we are getting down to the nitty gritty:D

Larry Gibson

[madsenshooter]

Ideal quit selling the #1 alloy, which was probably a babbitt to begin with, because there were problems with hard/soft areas in the bullets. That could be from a lack of stirring. I simply start with a high tin alloy then use a MPP/OXY torch to melt the copper in. It quickly alloys with the tin. There is actually a lot of research one can find on the web, had to do with hardening of battery plates. I didn't read all the previous posts before jumping in here, but what I got from my reading of the research was that the copper serves as the central point in a lattice network with the other elements surrounding the copper atom. Hard, not brittle, with good expansion characteristics. Experiments with a very large hammer on a 300gr 45 cal flatpoint has shown that to be true, along with this 35 cal high velocity experiment. Boolit on the right was a solid, left a hollowpoint. Both shot into a box of wet papers at 100yd, started out around 2200fps.

http://castboolits.gunloads.com/imagehosting/thum_12364f73ebef760d0.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=4622)

[popper]

Read some info on an old greek metal, like 95% Cu/5% lead, Molybdochalkos. O-T bullet alloy sounds like battery grid metal to me. Watch the on-line phase diagrams, they are computer generated. Some of the compounds don't form and others are only temporary. Hopefully, we will see more posts on this subject.

[popper]

I think this explains it. http://www.copper.org/resources/properties/703_5/703_5.html

[sqlbullet]

I know a guy that runs a bronze fine art foundry. I wonder if I could convince him to help me cook up a custom alloy using his furnace....

[popper]

Only process I can find that supposedly works is to melt the copper (1700deg) and add tin to molten copper to Cu/Sn ratio you want, reduce the temp and add hardball (Pb/Sb).

[sqlbullet]

Well, I got a case of the clever and looked up the binary phase diagram for Cu/Sn and thought some 50/50 tin copper looked about right. Full solution at about 700°. I completely forgot that those diagrams are always in C, not in F.

So, I dropped two pounds of tin in the cast iron pot, and put it on high and let the tin melt. My set up has two burners so I put a 4 lb ladle on the second burner, added about 1/2 lb of copper and a maybe 8 oz of the melted tin, and hit it with the MAP torch. After about 3-4 minutes I had an alloy, so I dumped it in with the rest of the tin. Life is good.

Next 8 oz of copper worked find too, went in with the tin. For those keeping score I now have a 33% copper, 66% tin mix in my dutch oven.

By the time I had the third batch of copper melted I knew there was an issue. The copper/tin was had a hard surface and was mushy underneath. That is when it hit me that binary phase diagrams are in C.

I added another 2 lbs of tin, and about 15 lbs of 95/2.5/2.5 and about 15 lbs of 96/3/1. After cooking for about an hour and hitting the harder chunks with the MAP torch, I had grainy liquid at 900°. About like WW is around 540-550.

I did cast just a few boolits with it. THey were VERY pretty, as one would expect with 10% tin. I made 40 one lb ingots of this high copper/high tin mix. These should be in the vicinity of 82/2/12/4 of lead/antimonty/tin/copper.

I plan to use these to sweeten my normal mix of 95/2.75/1.75. Two lbs should give me 94/2.75/2.75/.5

We will see where the hardness is, how brittle they are and how they shoot.

[sqlbullet]

On a side note, I found among my mostly tin/pure tin bar solder stack a 1 lb bar of 97% Sn 3% Cu. I should have taken a hint then that I wasn't going to get a stable liquid solution of 50/50 Sn/Cu without firing up the acetylene torch.

[popper]

You had 2 burners and a MAP torch on it? I wanted to try it but I didn't think I could with the MAP torch. I tried using MAP years ago to silver-solder AC stuff and couldn't get the heat high enough. Will a dutch oven really take that temp? Time to get one made in USA and another MAP cylinder. Did the tin fume? Cu is 1700, Sn is 450, boils @ 4700 F. Sn/Cu/Ag should be about 470F. I assume you ladel poured.

[303Guy]

I've had hard and soft patches with a copper containing ally. I was getting cold shuts in the casting and it looks like one of these coincided with the case mouth leade start interface and the boolit appears to have expanded at that spot then actually twisted on that plane in the bore as is evident by the rifling shear above the plane and not below. The cold shut forms a plane through the boolit diameter.

http://i388.photobucket.com/albums/oo327/303Guy/MVC-524F-1.jpghttp://i388.photobucket.com/albums/oo327/303Guy/MVC-521F-1.jpg
Notice the uneven expansion (or compression) into the paper patch.
The colour is a camera thing not from copper.

[popper]

Looks like the symptom of reduced shear strength. The part left of the 'wrinkle' is in the case and is straight. The part out of the case looks like a twisted banana, but that cannot happen in the bore so I assume the stresses relieved themselves after it left - not impact damage. We hit the base with 5k # F, twist the nose for 20 uSec and hope it keeps it's shape 1000 uSec later. That is a 2 groove 303 with 1/16 twist? So what does a 1/9 or 1/10 twist do to it? I'm not sure that is due to 'bad' spots in the CB.

[303Guy]

It's a 1-in-10 two-groove. I think or thought the bend was from impact - now I'm not so sure. That would be a lot of stress relief to bend that much and there was impact. I know this batch of boolits had cold shuts and soft spots. Clearly the boolit expanded into the space in front of the neck which probably weakened the boolit at that point and I think there was a cold shut there too which made it weak enough to flow. That was a very low pressure load. The rifling shear in front of the twist plane is due to rust damage in the bore. This gun is a tack driver with jacketed's but hopeless with cast.

[popper]

Cu has a wonderfully huge temp expansion coefficient. You probably are correct about the weak spots. The nose just didn't appear to have much impact damage, compare with #48.