Boolits from zinc/pure lead 50/50 alloy; interesting results.

[Onty]

Here is the thread about making bullets from 50/50 zinc/pure lead alloy: http://www.canadiangunnutz.com/forum/showthread.php?t=390251 . Look at those boolits (shiny ones), they are remarkable.

http://i138.photobucket.com/albums/q273/MOUICH/zincbulletswithhardnesstester.jpg

Better yet, see how undamaged the look after passing through 7” of pine.

http://i138.photobucket.com/albums/q273/MOUICH/recoveredzincbulletsfrompineblock.jpg

According to gentleman who cast them, they have such low friction that they were easier to size than lead ones. Also, accuracy was way better than from WW, using 44 rifle.

If I have it right, this alloy is about 83-84% of WW, not bad for larger calibers, especially 45.

[qajaq59]

I couldn't get to that page without logging in. Apparently you have to register?

[Matt_G]

I couldn't get to that page without logging in. Apparently you have to register?

Looks like it. I hate forums that require you to register just to browse. [smilie=b:

[Whitespider]

Interesting that zinc alloyed with WW didn’t work out, but zinc alloyed with ‘pure’(?) lead work OK.
And no lube used on the bullets, hmmmmmmm....

For those of y’all that don’t want to register on that board, here’s a copy and past (of sorts) of the thread.

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***jbunny***(9/29/09)
has anybody here experiment casting with zinc or zinc alloy?????
jb
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***green***(9/29/09)
Do you mean casting bullets?
Tried casting bullets from a zinc alloy and found cutting the sprue very difficult because the zinc alloy is very hard. The bullets weigh about 2/3 what lead does. IIRC the alloy i used was called Kirksite.
This was tried by hanloaders in WWII when jacketed bullets were unavailable. Heard there were high pressures reported because the bullets were hard all the way through and engraved hard.
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***jbunny***(9/29/09)
Green; i a'm glad u replyed. i know now that i'm not the only crazy on this list. LOL. i have been experimenting the last 2 days with lead zinc alloy. wheelweight lead and zinc makes a puty. pure lead and zinc mix 50-50 make a eutectic alloy. i cast a bunch today and my 44 cal 240 gr swc normaly weigh 250gr with #2 alloy. with this zinc alloy there around 136 gr. i will try shooting some tomorrow. i plan on shooting them dry, no lube. they are as hard as copper. here is a few pics on my make shift viberator for casting. works like a hot dam. a old sears hair clipper that u could not hang on to. i removed the 2 screws that held the cutter head on an bolted it on the the bottom of the c frame. the other pic is of the bullets and my princess auto hardness tester. u can see the bullet on the left with the lube is a lead bullet with the hardness punch on top. the zinc bullets have a very shallow punch mark. more later
http://i138.photobucket.com/albums/q273/MOUICH/castingvibrator.jpg
http://i138.photobucket.com/albums/q273/MOUICH/zincbulletswithhardnesstester.jpg
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***kodiak1***(9/30/09)
The fumes from lead are bad to inhale I can only imagine what zinc mixed in there would be like!!!
No I haven't tried it.
Good Luck Ken.
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***jbunny***(9/30/09)
Ken; i wear a painting resperator when casting and the doors are open. i got to try these out today. YAAAAAAAHHHHOOOOOOOO. loaded with 14 gr of unique, 2000 fps, 3 in groups at 100 yds.
http://i138.photobucket.com/albums/q273/MOUICH/3bullethardnesscompare.jpg
the bullet on the left is lead bullet water quench. notice the wide deep crater from the hardness tester. the middle one is zinc and the one on the right is a barnes solid copper. notice the copper and zinc craters are the same size, same hardness. http://i138.photobucket.com/albums/q273/MOUICH/recoveredzincbulletsfrompineblock.jpg
in this pic is 2 recovered zinc bullets from a dry pine block, 7 in penetration, the barrels are mirror clean. these were loaded dry, no lube. they were sized with a lee sized with no drag and less effort that alox lube lead bullets.jb
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***trevj***(9/30/09)
Niiiiiiiice!
Sounds like another great way to salvage some of that zinc 'contaminated' alloy I keep reading about!
Cheers
Trev
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***canidae***(10/1/09)
There is thread on Cast Boolits about using sulphur to separate zinc from molten lead.
http://castboolits.gunloads.com/showthread.php?p=679073#post679073
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***Andy***(10/1/09)
There are no toxic lead fumes emitted in the casting process - the temperature is far too low for that to occur. Neither is any measurable amount of lead absorbed through the skin by handling lead bullets, but it can be ingested. The same can be said for zinc.
Funny that this thread would pop up the day after I smelted some zinc wheelweights into ingots. I only see about 1% zinc and 3% steel in what I have picked up over the years, and it was only in the past year that I've saved the zinc.
I would think that zinc would make a crappy bullet - very light for its size, and hard (and brittle). Given that and its cost, a lead alloy or pure copper makes a much better bullet, but I appreciate someone experimenting.
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***Onty***(10/1/09)
How soft is that alloy? Did you try to improve it with more zinc?
Did you mean 50% weight pure lead and 50% weight zinc? Just 136 gr? If I have it right 50/50 alloy should be about 83% of pure lead. Since those 250 gr bullets from No. 2 alloy are usually heavier when cast from wheelweight, I would expect that bullet from noted alloy should be about 210-215 gr.
BTW, those bullets are just beautiful. Let us know what accuracy is.
Regards, Onty.
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***jbunny***(10/1/09)
they are way more accurate in my rifles than wheelweight lead. so far with 1 range session 3 in groups at 100yd. with win bulk 240 gr bullets the same rifles(1 have 3 44 mags) shoot 1 big ragged hole at 100 yds with the bullets touching the rifleing. i loaded these zinc bullets a little shorter for the first time. i was playing it safe. they shot good enough to make me order a 4 lb keg of unique today. as for bullet weight, the only formula i use is the SWAG formula. my next step is to modify the mould. i'm gona remove the sprue cutter. i'm gona try casting with the big lee electric melter as the temp seems to be more criticle. jb
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***Grizzlypeg***(10/1/09)
Zinc's harder than lead isn't it? I get that impression from carburetors and other automotive parts cast from pot metal. Might be wrong though.
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***jbunny***(10/1/09)
http://www.muggyweld.com/melting.html
this is the melting temp of metals. pure lead and zinc make a eutectic alloy that melts around 670 deg far.
http://www.tedpella.com/company_html/hardness.htm
this is the material hardness tables. zinc and copper are about equal. my hardness tester more or less confirmed that. the coefecion of friction of zinc is way better than copper or lead and when i sized these dry , and i could tell that there was way less drag than lead bullets. this is turning out to be a worth while
project fo me anyway.
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***trevj***(10/1/09)
I think this info would cause a fair bit of interest on the Castboolits site.
Lots of guys over there that are processing wheel weight over a turky fryer burner, and getting the zinc into their alloy.
Anyway, keep on posting this stuff! ood info to know.
Makes me wonder how fast a really light 225107 would be able to go.
Cheers
Trev
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[257 Shooter]

Onty, That is interesting. Please keep us updated.

[S.R.Custom]

So I'm wondering if you can push these 1/2-breeds fast enough to make up for their lack of mass? You know, so their momentums are equivalent... I know, their ballisc coefficients would suck, but who cares about that in a pistol bullet?

[Echo]

As arte Johnson used to say - "Verrrrryyy Eenteresting..."

I will continue to watch this thread.

[Whitespider]

Instead of increasing velocity to make up for lost mass...
I was thinking of recovering some mass by removing the (apparently unnecessary) lube grooves and experimenting with alloy.... say a 2:1 lead/zinc instead of a 1:1. A little more length to the bullet and a TC nose would also add a bit of mass and increase BC. Just some thinkin’ on my part.

[Ricochet]

I'd be cautious removing grooves with alloys much harder than the lead ones we're used to. Copper alloy jackets are harder, I know, but they're thin and have lead inside. Solid copper alloy bullets commonly have grooves to allow for rifling displacing metal. I've just been browsing around reading about zinc alloys and note that the common Zamak 3 or Alloy 3 die casting metal has a Brinell hardness of 97, and stuff called KS used for casting decorative items has a 151 BN. Mild steel's only around 120. Hopefully our barrels are somewhat harder, but if the displaced metal doesn't have somewhere to easily go, the pressures could go way up.

[StarMetal]

I'd be cautious removing grooves with alloys much harder than the lead ones we're used to. Copper alloy jackets are harder, I know, but they're thin and have lead inside. Solid copper alloy bullets commonly have grooves to allow for rifling displacing metal. I've just been browsing around reading about zinc alloys and note that the common Zamak 3 or Alloy 3 die casting metal has a Brinell hardness of 97, and stuff called KS used for casting decorative items has a 151 BN. Mild steel's only around 120. Hopefully our barrels are somewhat harder, but if the displaced metal doesn't have somewhere to easily go, the pressures could go way up.


John,

You're right about the grooves cut into total copper bullets, like Barnes Triple X, but they are also cut to reduce bearing friction area which in turn reduced pressure to push the bullet through the barrel. Another thing too some companies that made both styles of bullets, that is all copper with the grooves and the conventional jacketed with the lead core, use the groove also that the two different bullets in the same weights shoot pretty much the same.



Joe

[Cap'n Morgan]

I like the "vibration casting" setup! Been toying with the idea... should improve fill out.

[Pepe Ray]

HWOOW--STOP==TIME OUT!!!

This is, indeed, very interesting and should be examined further,
BUT
The subject is dealing with straight (pure?) lead mixed with what alloy of zinc?
At first glance this throws suspicion at tin and /or antimony as being a/the culprit in the poor alloy results. Really?
And pure lead is already at a premium, being highly desired by the BP community.
Creating another market for using in the zinc alloyed projectiles may cause problems.
Seems that there are a lot of unanswered questions here.
Who's gonna do the research to find the answers?
I suggest that the first thing to do is to establish some identification guidelines to avoid further confusion in the discussions. My Crystal ball is broken and my mind reading skills are kaput!!

At any rate, go slowly.
Pepe Ray

[lathesmith]

Whoah, this post goes against everything that I have ever seen and read about zinc - lead alloys. Has anyone else actually confirmed that lead and zinc combined actually makes a castable alloy? Like Pepe points out, if this is true, then tin and possibly other metals in small amounts is what ruins a batch of alloy, rather than zinc alone. I'm watching and listening, I Hope there is some reasonable way to get a castable alloy from zinc, but at this point I am not entirely convinced. Keep the info coming guys, I believe you have a captive audience...if this is indeed the real deal.
BTW, if you actually are able to cast projectiles out of zinc alloy, NEVER, EVER shoot them at an indoors baffle-type trap--these would have horrific potential for ricochet, and such bouncing around would have disastrous consequences.
lathesmith

[qajaq59]

Interesting.... I'd like to see where this goes.

[odoh]

Some yrs back, I recovered several 50BMG boolits from the club berm but they wouldn't melt and just floated in the mix so assumed they were zinc. If so, someone must knew something back then ~ IIRC (and thats a big ? mark nowadays) someone did mention one of the BMG guys using zinc.

[runfiverun]

zinc alloyed with pure lead has been done for years.
zinc is also used at the foundry to pull tin from alloys to clean it up,so they can start over with clean alloy.
i recall stories of roundballs being poured with zinc/pure alloy to increase the penetration on african game.
reason the fmj's that came out were a hit in africa [the 275 rigby,303 etc] penetration.
if i was gonna go in this direction i'd be messing with lee tumble molds..
zinc is not the enemy,it has it's uses.

[stocker]

I'm assuming that your 50-50 alloy is calculated by weight which would mean the volume of zinc far exceeds that of lead. I have to wonder if you shouldn't try working the percentages (at whatever proportion you care to try) by volume of the two metals rather than weight and see if they still alloy well. You would certainly gain some weight back working by volume. Interesting and possibly some hope for the future. I have yet to encounter a zinc wheel weight but I'm sure they're coming.

[Ricochet]

I'm assuming that your 50-50 alloy is calculated by weight which would mean the volume of zinc far exceeds that of lead.
Pretty close to 2:1, isn't it?

[Ugluk]

Interesting! I got buckets of sorted zink weights..
How about making a softnose with a zink/pure shank? Feasible?

Could open up a whole new field of custom molds perhaps.

[docone31]

I am no longer alone!!!
I have been mixing high amounts of zinc in my paper patched Boolitts. I mean high!
I have been getting excellent results.
I have this crud metal that I got from someone. It has a foamy whatever top to it. I have been thinning down the metal to make it castable. I am not big on waste.
With my .303 British, and .308(s), I get enough penetration that I have never recovered a casting at 100yds. Never. The berm is sugar sand.
The paper patched loads do not key-hole, are an higher POI than jacketed, and I get excellent castings.
I use Lee Molds. I run them hot!
My Muzzle loaders I use pure lead. The rest, I have this blend that has been working so far.
I am not sure zinc is the enemy. I have perhaps fired over a thousand rounds in both calibers so far.
No issues yet.

[Onty]

Thanks Whitespider for copying that thread, I was all day out, chasing 357 brass and those so illusive primers.

As for appropriate boolit design, I was thinking about LBT configuration with couple greases groove in order to reduce contact surface and consequently friction in the barrel, something like this (45-265, 44-250, 41-215 boolits);

http://img2.pict.com/a2/91/f9/1708479/0/412c442c45zinclead.jpg

[turbo1889]

This post deleted by original poster.



I am in process of deleting everything I have ever posted about casting with zinc because I have decided I will not share any of the knowledge I have learned over the years about casting with zinc due to the bloodthirsty prejudiced posts of some members on this forum viciously attacking those who cast with zinc. I will not share my knowledge with the enemy.

[Ricochet]

As for zinc causing trouble when combined with tin and/or antimony, I read somewhere today when looking around for info on zinc & lead that metal recyclers use zinc to remove tin from lead alloys. That suggests that they form an intermetallic compound. (As do tin and antimony.)

[Onty]

...Even then, though, if it works I wouldn't recommend these bullets for long term storage. I think over time "Zinc Pest" is almost a sure thing with such a combination.

"Zinc Pest" you mentioned, can it be prevented with boolit lube or some sort of wax coating?

[Whitespider]

What... is...
"Zinc Pest" ??

[turbo1889]

This post deleted by original poster.



I am in process of deleting everything I have ever posted about casting with zinc because I have decided I will not share any of the knowledge I have learned over the years about casting with zinc due to the bloodthirsty prejudiced posts of some members on this forum viciously attacking those who cast with zinc. I will not share my knowledge with the enemy.

[Bent Ramrod]

Has anybody on the thread mentioned the melting point of this "eutectic" mixture of 50:50 lead and zinc?

The one time I got zinc into my lead the mixture had the castability of oatmeal, and that at the highest setting on my pot.

Sharpe said that Kirksite A, melting at 717F, was the only practical zinc alloy for standard casting methods, and even that gave trouble at times. The fouling which sometimes accumulated on the moulds had to be removed with muriatic acid, and the blocks boiled in water as soon as the zinc disappeared. The melting and casting qualities of most zinc alloys require die casting under pressure.

Also, an exact groove diameter mould was indicated. The average Ideal at the time cast 0.003" over nominal, which would tend to raise pressures if cast in zinc.

Still, if they can do it, this is an important development.

[Onty]

Here is the answer:


***jbunny***(10/1/09)
http://www.muggyweld.com/melting.html
this is the melting temp of metals. pure lead and zinc make a eutectic alloy that melts around 670 deg far.
http://www.tedpella.com/company_html/hardness.htm
this is the material hardness tables. zinc and copper are about equal. my hardness tester more or less confirmed that. the coefecion of friction of zinc is way better than copper or lead and when i sized these dry , and i could tell that there was way less drag than lead bullets. this is turning out to be a worth while
project fo me anyway.

[XWrench3]

ok, so even if it is entirely possible to cast perfect boolits this way. 2 questions scream out of my puny little brain. 1) how will this affect barrel wear? especially with no lube. and 2) besides just burning up zinc for target practice, is there a reason we want boolits that hard?

[Whitespider]

Well, apparently all is not well in candy land.
It appears the lead and zinc did not mix after all. Probably was just too good to be true.
Here’s the latest...

-----------------------------------------------------
***Whitespider***(10/3/09)
Hello all,
First, allow me to introduce myself.....
.....Also, I’m an import (of sorts) from the castboolits site, one of our members over there posted a link to this thread. This is quite interesting and I’ve a couple questions...

jbunny,
When say your alloy is a 1:1 lead/zinc, is that by weight or by volume? What I mean is, did you weight out say, 10-pounds lead and 10-pounds zinc, or did you use say, 5 ingots of lead and 5 ingots of zinc (volume)? It would make a big difference given the difference in mass of the two metals.

The other question is about the ‘pure lead’. What is the source of your ‘pure lead’, is it certified or is it some sort of scrap metal? I’m not questioning your word, I’m just trying to determine what elements present in wheel weights cause the casting problems when alloyed with zinc.

Thanks a bunch...
WS
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***ahsly***(10/3/09)
Have you noticed any throat erosion in your barrel? I was talking to an old-timer about casting bullets not to long ago and he was telling me that he had a big stash of a lead/zinc alloy that he used to use for casting bullets for his 30-30. After about 200 or so rounds (from new) he said the barrel was almost completely shot out.
He figured the zinc was the culprit, and I might be inclined to agree with him. IIRC there used to be a line of bullets that were sold as cleaning bullets for handguns that had a zinc band at the back and they were used to clean heavy leading from barrels. They had a warning on them, to avoid excessive shooting using those bullets.
I think that Zinc (although just as hard as copper) lacks the self lubricating qualities of copper.
Any signs of excessive wear? You said the barrels were mirror bright after shooting.
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***joe-nwt***(10/3/09)
I don't cast my own bullets but I shoot cast. This is an interesting thread but I have a question. If you eventually end up with some zinc fouling in a barrel, what would you clean it with? Will standard solvents work on zinc? Might be something to look into before you get to that stage.
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***joe-nwt***(10/3/09)
I don't cast my own bullets but I shoot cast. This is an interesting thread but I have a question. If you eventually end up with some zinc fouling in a barrel, what would you clean it with? Will standard solvents work on zinc? Might be something to look into before you get to that stage.
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***jbunny***(10/3/09)
mr WS; did u just come from a cast bullet list where the list owners name is "chas"????
update on todays findings. lead and zinc is suposed to form a eutectic alloy as i was told by a metalergist on an other list. well my pure lead (scrap but soft by the fingernail test) zinc alloy did not mix. that why my bullets weigh 136 gr. pure zink. when i dipped from the bottom the bullets were soft and weighed almost 250 gr. i will be talking to alloy specialist on monday. maybee i shouldof used borax for fluxing instead of parafin wax. i will know more on monday. i have the hard sprue cutting problem licked. the vibrator is working great and the bullets are looking great. i have a range date on tuesday. more later jb
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[rob45]

According to Lyman Cast Bullet Handbook (Third Edition), page 49

Zinc % Solubility in pure lead at 752 F = 1.7%

I would like to know how someone thinks they can obtain a 50/50 alloy of zinc and lead after considering the above information.

[Cap'n Morgan]

I've been searching the net for zinc/lead alloys after reading this thread. Precious little has emerged - matweb.com, which list thousands of non ferrous alloys, has only a few soldering alloys listed with small amounts of zinc.

At Freepatentsonline.com an aluminum soldering alloy is listed:

"...of a tin/lead/zinc alloy consisting essentially of, by weight, from 1.7 to 2.2 percent aluminum, from 0.01 to 0.02 percent magnesium, from 45.9 to 50.4 percent zinc, from 14.2 to 34 percent tin, and from 16.6 to 36.7 percent lead"

And this is from http://chestofbooks.com/crafts/metal/Metal-Worker-Assistant/Remarks-on-Alloys-of-Copper-Zinc-Tin-and-Lead-etc.html:

"Zinc and lead are also very indisposed to mix alone, although a little arsenic assists their union by "killing" the lead, as in shot metal."

Apparently the vote is still on

[jbunny]

hi, newbie sortoff; i'm the chap u are talking about that's casting zinc bullets.
i was talking to purity alloys in surry bc yesterday and the condensed version,
vibrator is good , iron or steel melting pots and ladles are a no-no for zinc casting.
the zinc will pick iron from the pot and ladel and become harder to pour which
i experiancing. the info that i first got about pure lead and zinc making a eutectic
alloy did not work for me the lead was on the bottom and the zinc on top. if i diped on top, hard bulletes. dipped from the bottom , soft bullets. i'm haveing trouble getting the
base to fill flat, and it's getting worse. the rest of the bullets fill real good. today i tried
machineing the base flat on 6 bullets and 5 with good looking rounded bases.
this pic tells it all
http://i138.photobucket.com/albums/q273/MOUICH/zincbullettarget.jpg

this is what i did to over come the hard sprue cutter problem. i cut a 3/8 coupleing
nut in half and welded it to the side of the spruecutter. i welded the rod to the bold
of center so the vibrator does'nt vibrate the bolt out.
http://i138.photobucket.com/albums/q273/MOUICH/bulletmould.jpg
so now i'm in the market for a nose pour bullet mould in 44 and 357. any ideas??
sorry for the long post. jb

[nonferrous]

How about just cutting the sprue sooner, while it's still soft?

[sagacious]

According to Lyman Cast Bullet Handbook (Third Edition), page 49

Zinc % Solubility in pure lead at 752 F = 1.7%

I would like to know how someone thinks they can obtain a 50/50 alloy of zinc and lead after considering the above information.

The 50% zinc alloy is far too good to be true, and without casting aspersions at anyone, had a very distinct ring of unbelievability to it.

50/50 zinc-lead alloy isn't going to happen. I tried a few lead/zinc "alloys" back in the late 1980's, and I can tell you as a point of fact that any more than about 1% zinc will not dissolve into the lead-- in fact it will float around on top exactly like oil on water. You can see the liquid zinc on top of the lead; it's as plain as day.

One should be skeptical of any "revolutions" that are announced online concerning basic metallurgy and commonly-available metals.

[sagacious]

...
the zinc will pick iron from the pot and ladel and become harder to pour which
i experiancing. the info that i first got about pure lead and zinc making a eutectic
alloy did not work for me the lead was on the bottom and the zinc on top. if i diped on top, hard bulletes. dipped from the bottom , soft bullets.
...
This is exactly what happens-- the zinc simply floats on top of the lead. Use caution with unverified info you pick up on the web.

Zinc will slowly dissolve a cast-iron pot until it's paper-thin. The sides of the pot become really shiny and "wetted" with zinc, and then you can see the zinc slowly dissolveing the iron. It will shortly destroy your casting pot, and also screws up your zinc alloy.

The more immediate and dangerous problem, is that as the zinc busily devours your iron casting pot, it will eat a small hole through at the bottom. Then, suddenly, molten zinc will be squirting out from the bottom or side of your pot. Not fun, and it certainly holds your attention. Zinc splashes will usually burn exposed skin far worse than lead will.

Zinc will also dissolve aluminum FAST. If the zinc melt is stirred with an aluminum rod, it will dissolve it right before your eyes, even though the zinc is below the melting point of aluminum. I need not give any warning about melting zinc in an aluminum pot!

Anyone wishing to work with zinc and zinc alloys should read-up on it before they begin pouring.

Hope this saves someone some grief or some burned skin. Good luck, and stay safe!

[jbunny]

This is exactly what happens-- the zinc simply floats on top of the lead. Use caution with unverified info you pick up on the web.

Zinc will slowly dissolve a cast-iron pot until it's paper-thin. The sides of the pot become really shiny and "wetted" with zinc, and then you can see the zinc slowly dissolveing the iron. It will shortly destroy your casting pot, and also screws up your zinc alloy.

The more immediate and dangerous problem, is that as the zinc busily devours your iron casting pot, it will eat a small hole through at the bottom. Then, suddenly, molten zinc will be squirting out from the bottom or side of your pot. Not fun, and it certainly holds your attention. Zinc splashes will usually burn exposed skin far worse than lead will.

Zinc will also dissolve aluminum FAST. If the zinc melt is stirred with an aluminum rod, it will dissolve it right before your eyes, even though the zinc is below the melting point of aluminum. I need not give any warning about melting zinc in an aluminum pot!

Anyone wishing to work with zinc and zinc alloys should read-up on it before they begin pouring.

Hope this saves someone some grief or some burned skin. Good luck, and stay safe!
thanks sagacious. i was told by purity alloys that zinc would pick up iron from a steel pot after i experianced the unmixed alloy in my pot. any idea on time frame for zinc
to eat through a pot. i realize pot temp and thicknes would probly have a bearing.
temp is very criticle for good bullets and i suspect that my pot has picked up
a fair amount of iron as my bullets are getting harder and harder to size. i am
getting good bases on my bullets now . i converted my mould to a nose pour.
silicon carbide crucible would be the way to go but there are problems with those
too. i will keep some zinc bullets to clean a copper and lead bore out and my
next big experiment will be useing 40 cal pistol brass as swaged jacket bullets.
jb

[sagacious]

thanks sagacious. i was told by purity alloys that zinc would pick up iron from a steel pot after i experianced the unmixed alloy in my pot. any idea on time frame for zinc
to eat through a pot. i realize pot temp and thicknes would probly have a bearing.
Yes, pot thickness makes all the difference. A thin rolled-steel pot (or crucible) will be eaten-through very quickly. I believe that some steel alloys are either resistant or immune to zinc dissolution-- a Google search may turn up some results for you on that. Most recently, I have been using 18-8 stainless crucibles as melting/pouring vessels, and they work well. But I remain vigilant and untrusting of molten zinc's ability to eat through what it's contained in, and always keep an eye on things. When the pot looks beat, I toss it just to be safe, but stainless lasts a long time. You can buy 18-8 stainless vessels at cooking stores that are perfect for melting zinc-- and lead too.


temp is very criticle for good bullets and i suspect that my pot has picked up a fair amount of iron as my bullets are getting harder and harder to size. i am
getting good bases on my bullets now . i converted my mould to a nose pour.
silicon carbide crucible would be the way to go but there are problems with those
too. i will keep some zinc bullets to clean a copper and lead bore out and my
next big experiment will be useing 40 cal pistol brass as swaged jacket bullets.
jb
You may need to flux your melt more frequently. Keep us popsted on your results with zinc, and with the 40cal brass-jacket bullets. I used to swage those for my 77/44 rifle.

Good luck, and stay safe! :drinks:

[AZ-Stew]

Interesting stuff, if we can make it work.

From what I see in the photos, though, no one on this board will use those boolits, anyway. They aren't frosty.

Regards,

Stew

[jbunny]

Interesting stuff, if we can make it work.

From what I see in the photos, though, no one on this board will use those boolits, anyway. They aren't frosty.

Regards,

Stew

ahhhhh but they are a hoot to shoot. i yell HIGH OHHH SILVER every time i pull
the triger.
cheers
jb

[lathesmith]

sagacious, I was wondering how much zinc it takes to be destructive to our casting pots. Is the amount necessary to be destructive greater that the 1.7% soluble threshold, or lower?
lathesmith

[Traffer]

I know this is an old thread. But I have found it relevant for what I am now doing.
As many of you know I have been developing a workable 22 rim fire reloading system for the past 3 years. I want to deal with a situation I had the other day. I discovered after fighting to mold some 40gn, 22lr bullets, that I had zinc in my batch of lead. I had been using very soft 6bhn lead and decided to add some harder stuff to the melt to get some harder bullets. Unfortunately it looks like I grabbed some zinc contaminated lead. Since I swage the bullets after I mold them, it is not critical that they be perfectly molded bullets. So I soldiered on with the molding of some 200 bullets. I found out after the fact that there was zinc contamination by putting a few drops of muriatic acid on the left over batch. Fizzing and foaming...sure sign of zinc. What percentage? I have no idea. The bullets were harder but it was very difficult to get a good idea of the hardness with the pencil hardness test that I do. My guess is that they are about 10bhn. They swaged up well (though a bit more pressure needed). I did a crimp test by measuring the amount of bullet pull in lbs to pull out of the crimp, I noticed something that seemed weird to me. The bullet pulled at about 78lbs of pull. (That crimp would have been about 30lbs with the soft lead). But the bullet pulled like taffy before letting go. It stretched to about twice the original length of bullet. (sorry no pictures as of now...I will try to get some). I am very pleased with what I have learned here. Lead-zinc alloy bullets may be something that will work out very well when they are swaged after molding. There are a lot of benefits that may be gained by Pb/Zn alloy.

[Wayne Smith]

Not if an uncrimped boolit pulls out of the case at 78lbs! Talk about high pressure excursions!

[therealhitman]

But the bullet pulled like taffy before letting go. It stretched to about twice the original length of bullet.

198444

[Traffer]

You will note that it WAS a crimped bullet. It was a deeply crimped bullet. I have tested some factory ammo... Remington Golden Bullets pull at about 25 to 30 lbs. And Winchester Super X pull at about 60 to 68lbs. My goal has been to make the crimps hold between 45 and 55lbs. I was not able to attain that with soft 6bhn lead. The highest pull rate I was able to get was about 35lbs, no matter how deeply I crimped them. That is why I went to a harder alloy. Again, the same crimp that held around 30lbs on soft lead held over 75lbs with the Zinc/lead that seems to be about 10bhn. In my research I have found that 22 rim fire loaded with modern smokeless powder needs a heavy crimp to provide the necessary confinement to get the powder to burn under compression. I am not 100% sure why center fire ammo does not require the same conditions. Perhaps because of the fact that there is a lot more powder in a center fire or because center fire cartridges provide the confinement to pressurize the burn by fitting in the gun tighter. Or maybe a combination of both. But in the book "Ammunition Making" by Frost, he is very clear pointing out the need to have the crimps consistently hold from 45 to 55lbs for match grade 22 rim fire ammo.


Not if an uncrimped boolit pulls out of the case at 78lbs! Talk about high pressure excursions!

[Traffer]

198444

I take it this is a shot at my eureka moment. If so, Yes it felt just like that. It was like "wow I can now do things that no one else has ever done...maybe"

[therealhitman]

Yes, definitely a eureka moment I would think. Lighter weight, added lubricity plus elasticized alloy potential? Does that all lead to lower powder charges for like velocities plus less mechanical wear combining to minimize erosion? Or am I excited over nothing? (wouldn't be the first time)