High Copper Alloys- Lets discuss this further

[felix]

Size is a function of antimony, and nothing else that matters in our alloy intentions. ... felix

[runfiverun]

yellow orange is lead oxide.

[303Guy]

Mine is more of a greyish yellow (or is that yellowish grey?) The alloy has softened so I'm thinking the tin and probably copper has burned off. That's from running the pot hot to clear the spout. Anyway, I've added the 50/50 I had and will add a bit of tin and give the pot a good cleaning.

[303Guy]

My mixed alloy which now has about ½ % antimony is no harder than the lead-tin with copper. It has less tin at 2½ %. It still needed to be run warm. It cast a little softer but has hardened overnight to about what the lead-tin-copper cast at.

I'm wondering if the trick is to dissolve as much copper into the alloy at a lower temperature to avoid free copper. The alloy I had seemed to be OK but needed to to run hot to cast properly and that's when the surface oxidation became a problem. I'm going to try an insulation fibre lid with wood chips on the melt (to consume any oxygen) and see if that will stop the oxidation.

[303Guy]

Well, last nights casting have hardened up a bit. I added some pewter which raised the tin to 3½ % (assuming there was no tin loss previously). The alloy cast quite well in one mold right from cold but another mold not so much. Wrinkles while cold then when hot it produced shrinking mid-shank with a satin like frosting around the shrunk area. Of course, the pot may simply have become too hot! Time to find the temperature probe. As cast from the first mold hardness was up there so we'll see what they do overnight. What I'm seeing is some castings are dropping fairly hard - harder than aged 50/50's but not as hard as CO's while others are dropping softer. So there's quench hardening going on there and the toughness seems right were I want it to be.

[badgeredd]

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[357maximum]

I think I figured something out........My "pure" lead I used on my 2nd to last batch (the batch I made my 7mmThors from)of 50/50 may have been a bit tin rich as it was lead pipe that I had smelted eons ago.....before I started keeping the unions/joints seperate from the pipe. When I added the 4% copperized RR babbit I obviously threw something out of whack. It made good boolits....I just had to be patient for the growth to stop.

I made a batch of 50/50 ww/pure 3 weeks ago but this time I used certified pure lead and the looooong "growing" issue has not happened in this batch...it has been 3 weeks and they are done growing. Too much free tin in my 50/50+4% Copperized RR babbit is very likely to have produced my LOOOONG growth time. My old batch of 50/50 simply had too much tin in it from the joints in the "pure" lead pipe. Now I know, good thing I have alot of lead pipe that has not had the joints mixed in. I will now save the tin rich leadpipe alloy for plinker boolits and use pure lead or lead pipe without the joints for making Edd's Copper Alloys. Lesson learned.

[303Guy]

If one were to nominate three desirable properties of boolit alloy, what would they be?
I would think malleability, strength and surface hardness. How does one give those (or any) properties usable values? Hardness we know, strength we could use shear strength or compression strength, malleability is going to a problem I think.

What about castability? How would that be defined? Or we could ask what makes good castability. We think that copper in the alloy provides desirable properties which is why we are following this thread so copper is likely to be included but the jury is still out so what have we concluded so far?

[303Guy]

What we NEED to know is the force needed to start the deformation.

I might be able to do just that. I'm planning on a hardness testing device in which the ball indentation is kept constant and the load measured. This same device can be used to draw a curve and determine the initiating load.

[Hamish]

I ran across an old question today and it occurred to me that the enhanced copper alloys being developed here might present a new face to the problem of long, heavy boolits for caliber, when pushed to high enough velocities to cause "pretzeling".

We know that elevating the CU makes for a very "tough" boolit, it does a very good job of resisting stripping and deformation.

What prompted the thought was the 6.5, and some of the problems associated when boolit weight is pushed past the 140's when pushing velocity, which would certainly be improved by an alloy that would resist torsional forces. For myself I wonder what could be done for the 6mm and more specifically, an ultra heavy boolit in the .22 calibers.

Not looking for a resurrection of any of the old drama surrounding the 6.5, just looking to approach an old problem from a new perspective.

[badgeredd]

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[runfiverun]

I wonder if some of that bowing is from the boolit hitting the water and one side cooling a little faster than the other.
added to the one side possibly hotter [between the cavity's maybe]
something like 25* would maybe be enough when combined with the quick cooling.

[badgeredd]

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[303Guy]

I have found bent boolits with my long torpedo 303 boolits I cast with copper enhanced alloy. These were dropping out the bold bent. No water quenching. It's just occurred to me that the copper alloy drops from the mold very soft. I recently picked up a cooled boolit and bent it with my fingers. A while later I could not bend or straighten that same boolit or any others. My first bent boolit probably bend on dropping out the mold! Yours might be doing the same. Long boolits may just need more care when casting. Oh, adding more tin seemed to negate that initial softness - just an observation, not a suggestion.

[runfiverun]

[QUOTE=popper;2147196]Don't know it 180 FB RD or 165 308 is 'long/skinny' for cal, but I checked and haven't had any bent boolits from casting or Lee sizing (my Cu alloy). I did wonder about mold temp causing bending and other factors a while back. I checked some of the 30-30 left in one half of the mold (#2/Pb), broke them in half and saw the grain was not center'd. I HT some and did find the grain center'd better. QUOTE]

had to break this part out.
this sure gives some credence to the thoughts.

[runfiverun]

these things never seem to end do they
the rabbit hole just gets deeper and deeper and curiouser.

[bstone5]

Bump To Top

[bstone5]

I purchase lead that is 92- 6 -2 from a local supplier here in Houston.

92% Lead 6% Antimony 2% Tin

Could the copper be included easily by simply mixing in some of the Babbitt material available from RotoMetals.

I am looking for an easy way to include the small amount of copper with out changing the alloy I purchase.

The super tough has 8 % copper. This material would result in a lot of material with a dilution to get a small percentage of copper in the alloy.

if anyone has used the Babbitt material from RotoMetals for the addition of copper please indicate which products was used and the amount added to ten pounds to give a desirable level of copper in the 92-6-2 alloy.

I want to try to shot the alloy in a 308 Win gun made from a small ring Mauser many years ago.

I had rather purchase the material with copper already added instead of making the addition myself. I do not have a lot of wheel weights or pure lead, I just use the material purchased from the local supplier, Lead Products.



Thanks

[Jailer]

bstone, the image below is a screen shot of the alloy composition that I mixed up and cast using Rotometals supertough. I will have my test rounds loaded tomorrow and hopefully be out to shoot soon.

[bstone5]

Read again and did some calculations.

It appears it will require 2 ounces of the RotoMetals Super Hard to be added to each 10 pounds of alloy to get the copper to .1%.

From the reading it appears .1% of copper will harden the alloy of 92-6-2 to somewhere around to 15.

Has any one else came up with the 2 OZ. addition per 10 pounds of alloy?

Am I in the ball park with the 2 OZ addition.