High Copper Alloys- Lets discuss this further

[Jim Flinchbaugh]

Been a while since any activity here
I poured ~100 out of my home brew alloy yesterday, in the new mold that fits my Handi Rifle.
I found that the pot temp of 800 or so, and keeping the mold hot, and a 30 count between pouring and cutting, gave me a very nice,
perfectly filled out boolit. They where water dropped from the mold, sized and checked as soon as they where dry.
Sizes recorded to follow the growth. I'm gonna wait for a bit to load so they stabilize. Then the fun will begin seeing how they do.

[grunt37]

I'm not wanting to be offensive here guys, but you're making a lot of work out of it. Some of you are ignoring parts of our method that we are using to keep things as safe as possible in the air quality arena. The copper is being added to the babbit, NOT TO A LEAD MIX. The reason we do it this way is to avoid vaporizing lead into a dangerous gas as much as possible. Once we have a copper enriched babbit, we add it to a lead mix for our boolit alloy.

The babbit we are using is identical to the Rotometals Rotonickel (type #2) babbit. The reason we are adding copper to the babbit is it is cheaper for us to add the copper to our EXISTING supply of babbit. This babbit has almost no lead in it. You can get the same stuff (or very similar) we are mixing, by buying the Rotometals Super Tough alloy (type #3). Once our babbit supply is exhausted we'll likely turn to purchasing the already alloyed Rotometals type #3 alloy.

Now some are going to say this is an expensive way to go. IF one used the babbit for only casting boolits meant to go very fast, 5 pounds of the Super tough will last a very long time and be definitely cheaper than buying jacketed bullets. The basis for using the high copper alloys is to increase the strength of the alloy to resist deformation when fired out of a high pressure cartridge of 50,000 psi or so. We are trying to make a good Pb/Sn/Sb/Cu alloy that is consistent and accurate at high speed. It isn't a cure all for every ill of cast boolits. It is a specialized alloy for specialized applications.

Don't waste your time using this in medium and lower pressure loads. You're going to see little if any benefit. Our goal is to be able to push our cast grease groove boolits to the velocities of factory jacketed bullets in the 3000 fps range and perhaps slightly higher. One can get the velocities we are after with paper patching, but we're trying to get there without the jacket, copper or paper.

Edd

So at what velocity in fps should I be able to use plain based bullets up to? I cast for pistols mostly but love my .45-70 and .300-221

[badgeredd]

lkiyt

[NYBushBro]

First of all, a huge thanks go out to all who have endeavored to advance this aspect of alloy formulation.

I've spent the day (my day off) trying to absorb all of this info... can't say I own much of this - yet.

IIRC, the initial start of this experiment was based upon marine babbitt with addition of tinned copper wire to increase copper content.

It has been my impression (after trying to look up composition charts of various tin-based marine babbitt alloys) that marine babbit already had about 5-5.5% Cu (88-89% Sn, 5.5% Sb, 5.5% Cu) based upon some charts I googled online.

Has anyone tried to figure out what percentage of Cu (or other metals) the starter babbitt alloy actually contains - before and after Cu addition?

It might help to attempt to standardize the composition of the 'sweetener' alloy (even if we are using composition estimates for COWW or isocore alloy) to attempt to make this more repeatable - which, I am hoping, is one of the things we want to accomplish.

The poster who recommended the 4 different alloy XRF tests (in my opinion) might be on the right track - to help determine starting compositions, as well as 'results' of addition of Cu to the babbitt, and after the addition of the 'sweetener' to the 50-50 mix.

I must be honest in saying that I was more than surprised to see ~5% Arsenic in the samples presented for assay... and also wondered whether there may have been transposition of figures.

I'm also looking forward to seeing how this will affect velocities of plain-base molds (of which I own quite a few).

Jacketed velocities with Cu-enriched plain-base CB's in obsolete calibers (with expansion and weight retention results like the sand dune HP photos) would be awesome... not to mention extremely useful.

[badgeredd]

98745

[Oreo]

Has adding copper shown any improvement in boolit weight retention for hunting purposes? I'm thinking of hunting boolits where expansion is desirable but fragmentation is not.

[Jim Flinchbaugh]

Oreo,
that is one of the supreme desires of this alloy. Making the boolit
"tough" enough to with stand chamber pressures and launch speed without
the nose slumping on muzzle exit, and remain malleable enough to not fragment
on impact.

The ones I've cast, have a BHN of 26 after 3 months, and you can beat them down
to foil thickness without losing any weight. That is however, different than velocity impact
which I have not determined yet. I've just been trying to get the load to group so far, which
I'm getting close on.
I loaded up some more yesterday for the next trip to the range, maybe today if it quits snowing

[popper]

Oreo - someone posted on a 7mm CM / coppered results in deer. IIRC the comment was that it would be good at reduced fps. http://castboolits.gunloads.com/show...=1#post2571304
The bottom recovered is 308@2400 from ~ 25' into a frozen rock pile. Not much left of it. I think it hit a 12 ga steel wire before the rocks. The 40s from 15' worst case looked like a chunk broke off, the others just got miss-shaped, TC is now same as body dia. I didn't see any of the petaling and petal fracturing. Rock pile was blue/grey paving chat - really, really hard stuff - granite? Don't think it will blow apart on bone at reasonable hunting velocity.

[stephenj]

Ok .. i just spent about 5 hours over a couple days reading this thread
Along with poppers thread .

While a lot of the science involved is over my head i ha e learned a whole bunch
Probably more then that is good for me .
But this thread might just get me to where i want to be with my 6mm remington
I also leaves me with a ton of questions that i will try to answer for myself by going back threw all this info
It also makes me want to try this myself .

Maybe someone can speed things up for me
If any of you fellows have any of the enriched babbit left that you wont need
I wouldnt mind having enough to do 10 or 20 lbs of lead

[RickinTN]

I have been following this thread with much interest. I don't/didn't have any of the babbit but thought there certainly is more than one way to "skin a cat". I do have what I think would be considered Monotype with a high copper content (over 2%) and I regularly use lead free solder which has 5% copper content for adding tin to my alloys. I came up with a mix of clip-on wheel weights, magnum lead shot, pure, monotype, and the solder with 5% copper. I did use the shot and wheel weights with intentions of having arsenic in the mix to enhance heat treating properties. The last time the lead analyzing service was offered here I sent a sample to be tested. That sample came back as 2.3%sb, 3.29sn, .909cu, and 92.81pb. From what I understand in this thread my alloy should be very well balanced. Their test doesn't measure arsenic, but I feel sure it has ample content for heat treating. I have no way of measuring hardness. Along the way I realized that my several Remington 700 rifles, one in 30-06 and a few in .308 share the same or at least very similar long throat. I had Tom at Accurate molds do the 31-180R bullet for me which fits the throats of my rifles very well. As an added benefit the bearing surface of this bullet is much greater than most 30 caliber bullets and I think it will enhance the possibility of increased velocity. I have done very limited testing so far and have reached 2,000 fps in the '06 with good accuracy in the first load I tried. I'm looking forward to additional testing when weather/temperature permits and have high hopes for this bullet/alloy combination. I'm thinking the .909 cu content should certainly be enough to take advantage of the additional toughness offered by such an alloy.
Wish me luck! and thanks for all the information,
Rick

PS. I'm casting at 700 degrees with this alloy and have seen no need to increase the temperature. I do ladle cast and am pressure pouring. The weights of my bullets are very consistent.

[felix]

Rick, why do you need Arsenic for heat treating? Doesn't the copper offer enough "alloy imbalance" for heat treating? It would be interesting to see a phase diagram representing the sample you have had analysed. ... felix

[RickinTN]

Felix,
Everything I've read indicates the arsenic in small doses (.25% or maybe even less) will enhance the ability of the alloy to heat treat. I'm not, or wasn't aware the copper content could accomplish the same. I'm certainly not a chemist, and have been "brushing up" a bit on my college chemistry to help in this new found obsession which we share. It's been over 35 years since I was in the chemistry classroom and although some if it is coming back some is still just as clear as mud. I would be very interested to find what difference the heat treating has on this particular alloy but have no testing equipment to test. I would be happy to mail some samples before and after heat treat if someone would be so kind as to volunteer to do the testing. I do have samples which were heat treated and have aged about 90 days however the only air cooled samples I have are aged about 3 weeks. I'm thinking this difference may have an impact on the hardness test comparing the two.
Rick

[felix]

Rick, the very best way, in advance, to determine if an alloy we are interested in will heat treat is to: 1) Measure the temperature of the alloy at the point of first melting when applying heat from a cold start, 2) and then turn the heat off after the alloy is fully melted, very liquid like water, and then measure the temperature of the alloy when it first appears to get thick and slushy. The higher the difference in temperatures, the higher the probable hardness over time. Probable because the eventual hardness depends upon how fast the first made boolit is dropped from the mold into cold water. Make darn sure the liquid phase alloy is well fluxed before turning the heat off. ... felix

[NYBushBro]

After my second Monday (day off) trying to digest this concept (with moderate degree of success), I thought of something which I think is pertinent.

I feel that BOTH methods of adding Cu to alloys (Cu-saturated Babbitt metal, and CuSO4 displacement in alloy) BOTH have merit - and both should be continued to the ultimate end (ie: success.)

One factor that both factions seem to be neglecting is AVAILABILITY of necessary precursors (for either process.)

If both camps continue to develop their methods (and perhaps bounce ideas off each other from time to time), the end result would be TWO 'ways to skin a cat' - depending upon AVAILABILITY of resources (ie: babbitt, copper wire, CuSO4, or even - gasp - Pb, for that matter.)

I think it would benefit members of this forum for both factions to CONTINUE on their respective paths, with (hopefully) the end result being 21st century advances in 19th century ballistics.

(NOTE: I throughly enjoy this thread, and look upon it as sort of a 'think tank' experience.)

[popper]

I zinc'd (6 pennies) then CS'd 15# ( actually 12# - 3 Rotometal ingots , 20% $ increase now) of pure. Just want to state that it works OK, (edit: several asked if the CS drosses out Sb)doesn't pull any Sb out. Normally make my alloy then add Cu. Got a lot of the brown powder and ~ 1 tsp. metal skimmed off (ran the pot @ ~ 950F & hadn't cleaned the pot). Anyway, should be 0.5% Cu. I'll cast some 40SW to see how they work, then add more Cu & Sb - 50% Pb for rifle.
BushBro - Started the CS route cause I didn't have any babbitt. My conclusion is I don't need all the tin in the babitt. I did add some Sn (<1%) and didn't get any different results in casting or shooting. Cast ~ 5k boolits with the CS, about $0.0005/ boolit. Takes an extra 30 min to make the alloy. Still have 1/2# of the CS left.
Edit: maybe Roto will add some Cu to their high Sb ingots at a decent price, we wouldn't need to do this stuff.

[badgeredd]

The more input from several people we get, the faster we will arrive at some good conclusions.

[popper]

Been asked this question several times by casters so I went and figured out the answer, posting here.

CS weighs 4 times tin/zinc - just figured it out for another caster. I don't know how much tin or zinc is in your alloy so I can't say how much CS needs to be added. YOU have to figure the amount of tin (sic. zinc). The Cu will also alloy with Sb - doesn't remove it and it is good for the alloy. Pennies have only pure zinc and copper in them! Only problem I have with the zinc process is it takes a much higher temp to get the zinc to mix.

[AKbushman49]

popper & edd- I applaud your efforts to improve cast boolits, gave me alot of pause for thought, but nybushpro nailed it. I'm in an area which makes availability of supplies (babbitt and lead) difficult. I cast for most everything I shoot. So I'm looking for every advantage I can get. For me it's the technical aspect, for survival. When that 1200+ critter decides it's gonna do something detrimental to me, my wife, or property, I want all the advantage I can get. Jwords are cost prohibitive and mostly unavailable in the calibers I have. With my supplies dwindling I'm looking for options. So I'll put it to you what's your opinion of an alloy 2% Sn, 2%Sb, 0.12% As, 0.05% Cu, the rest Pb. Water dropped.
bushman

[badgeredd]

njiuy

[AKbushman49]

edd- Thanks for the prompt reply, Balmy? Christ I've been through 12 cord of wood already, we just got thru our summer in January Ha Ha. Necessity/economy/availability are my issues. Most of the weapons I shoot are 35 Cal +. Long gun and short. Short stuff no problem, but long guns well. I have a pistol alloy that dumped a big fuzzy brown a few yrs ago. But that alloy isn't up to rifle capabilities. I have some very old coww which was my base for the pistol stuff, water dropped it hardened to 16+bhn and that was cut 50/50 with cable sheath. But effective heavy rifle velocity was lower than desired. Hrs of cleaning barrels just don't cut it. Been looking at rotometals #3 for a possible remedy. If'n I do I got to warn the Post Office lady that IT's not to be returned till I get there. (its a +50 mi o/w trip) Ha Ha PS It's not the end of the world but ya can see from here.
Anyway again thanks for the work on this.
bushman