using zink in cast boolits

[josper]

recently I signed up to a group on Facebook "Reloading and casting for polite adults" this one guy posted that it's ok to add zink to your lead that you only had to run it hotter to get good bullets. I told him that it was a terrible idea and that if he shot these bullets at a club range it would screw up other members that salvaged this lead for casting. he got all defensive about it. He was giving this info to a new member that asked if he could use zink for casting his bullets. I advised the newbie to buy Lymans bullet casters handbook for the correct information. Was I right and how would you reply to these guys that push this bad info? whenever I'm smelting lead I'm ever so careful not to let any zink get into my alloy.

[kevin c]

He's right, and so are you.

It's been posted here that low quantities of zinc in lead are castable. Too much is not. Most casters prefer to avoid it altogether, and, that being the case, we're talking about berm mining some bullets made of a castable zinc containing lead alloy mixed in with bullets made of non zinc containing lead alloy. In other words, melting everything mined all together, you'll end up diluting the zinc down to levels well below what was castable in the first place.

IMHO, it's more problematic if folks start shooting all zinc bullets in quantity. Then the chance of getting a high zinc blend out of the berm is greater. Another reason to minimize zinc in casting alloy maybe that there's less understanding about how it changes how the alloy acts; all the long years of slowly accumulated experience on lead/tin/antimony/copper boolit alloys doesn't take zinc into account, so some folks might have to start over from scratch (for some applications it may be a non issue, though).

[quack1]

Sadly, if you are casting with wheel weights, your probably already have some zinc in your lead. I can't imagine wheel weight manufacturers bother sorting recycled wheel weights before they melt them down to make new ones. All they need from their alloy is to fill the mold well enough to have slightly legible weight numerals. Thankfully, so far, the zinc is still diluted enough to not give trouble with mold fillout.

[farmbif]

accurate sorting of scrap meals has become a very automated and exacting science. quick look through any of the metal recycling magazines and you will understand what I'm saying.
I guess I'm a purist when it comes to what I put in my casting pot, I make every effort possible to prevent any zinc to go into what I melt down to cast with. the guy on facebook can do whatever he wants, its a free country after all, but for me its lead, tin and antimony is all I want to use.
there was a member here who was making cannon balls with zinc, but that's something a bit different than casting for handguns and rifles.

[JonB_in_Glencoe]

I did a test with adding 1% ZAMAK III to 94-3-3 alloy.
Mostly, I wanted to know about hardness, and if it increased the BHN.
The result was so small, I'd call it negligible. I did notice the alloy being somewhat troublesome to pour if the heat wasn't increased by 50 or so degrees.
I ended up cutting the alloy with 50% pure lead and then it cast trouble free at a standard temp for that alloy (if it didn't contain 0.5% ZAMAK III).

[William Yanda]

"He's right, and so are you." Kevin C
I agree. If Cu in small amounts adds positive qualities to boolet alloy, might not Zn do the same?
Without a range standard, do shooters have an ethical responsibility to anyone who might recycle their boolets? My first take is, if I am recycling, I will deal with what I find. If I don't like the results I will adapt or move on. Of course, if we lived in California, it would be required that the bases of any boolets cast with an alloy containing zinc, would be stamped Z.

[cwlongshot]

He's right, and so are you.

It's been posted here that low quantities of zinc in lead are castable. Too much is not. Most casters prefer to avoid it altogether, and, that being the case, we're talking about berm mining some bullets made of a castable zinc containing lead alloy mixed in with bullets made of non zinc containing lead alloy. In other words, melting everything mined all together, you'll end up diluting the zinc down to levels well below what was castable in the first place.

IMHO, it's more problematic if folks start shooting all zinc bullets in quantity. Then the chance of getting a high zinc blend out of the berm is greater. Another reason to minimize zinc in casting alloy maybe that there's less understanding about how it changes how the alloy acts; all the long years of slowly accumulated experience on lead/tin/antimony/copper boolit alloys doesn't take zinc into account, so some folks might have to start over from scratch (for some applications it may be a non issue, though).
I agree here.

Prefer none but some alloy ya just dont know and quite likely it's already in there. If ya run hot or hotter a piece or three in a 20# pot probably could go un noticed. If something doesn't melt "fast enough" Ill pull it and set aside. Yea I know some alloys melt differently.

CW

[popper]

I deliberately cast some Zn'd bullets for 40sw, 2% and they cast/shot fine. Added some CuSO4 to cut down to 1%, still did fine (~1% Zn/Cu). Est. fps 950. Unfortunately they sized small and I got a lot of sideways hits but they expanded great (lube grooves disappeared on target) and I got light leading (alox lube - I never did PC any). About half made round holes, other half made rectangular holes. Accuracy @ 7 yds was fine. Added 1% Sb and they still worked great and sized properly. 2% gets a little 'stringy' when pouring but does work. So yes, a small amount of Zn is fine but you get lighter bullets.

[Conditor22]

A couple of % of zinc hasn't proven to be a problem.

Bad news for those who rely on public range lead, I know of more people casting/shooting zinc boolits (best done with hot alloy and 1 cavity steel molds, It can be done in 2 cavity mold if you are fast)

The percentage of zinc casters is low so the possible percentage of zinc from range lead should be minimal.

[gwpercle]

recently I signed up to a group on Facebook "Reloading and casting for polite adults" this one guy posted that it's ok to add zink to your lead that you only had to run it hotter to get good bullets. I told him that it was a terrible idea and that if he shot these bullets at a club range it would screw up other members that salvaged this lead for casting. he got all defensive about it. He was giving this info to a new member that asked if he could use zink for casting his bullets. I advised the newbie to buy Lymans bullet casters handbook for the correct information. Was I right and how would you reply to these guys that push this bad info? whenever I'm smelting lead I'm ever so careful not to let any zink get into my alloy.

Don't "reply " to them ...make sure your information is correct , post good information , and move on . Don't mention any names . A few zinc bullets in a range backstop full of lead will not "contaminate it beyond use" . A pot of Zinc contaminated alloy can be cast into small ingots and one small one used in a larger melt and will dilute the zinc to the point where you can get decent boolits out of it . Dilute the zinc tainted metal enough and you don't loose the entire pot.

Thanks for the Heads Up ... Sounds like some of the adults aren't so polite ! I like to avoid sites like that . Mom always told us to ..."Be Nice"...so I try .
Gary

[gpidaho]

Zinc and copper in trace amounts in the alloy are good things. They add hardness and strength to your cast bullet. I'm far to lazy to mine lead from a berm but the zinc in a small % of the scrap wouldn't be a worry of mine. As mentioned, If it floats at seven hundred degrees, skim it off. Gp

[jim147]

Future generations my have to learn to cast straight zinc. Not much new lead coming these days.

[tmanbuckhunter]

Future generations my have to learn to cast straight zinc. Not much new lead coming these days.

Plenty of it coming... it's just expensive as all get out. It's almost cost prohibitive.

[Winger Ed.]

Zinc is in the future of casting, and some are already doing it.

In range Lead, I've already found a couple.
I don't want to mess with it yet, so in my melting process, I raise the heat slowly.
That way the Lead melts first, and the Zinc boolits float to the top intact and can be skimmed off with the other trash.

The same method will also work on scrounged wheel weights that didn't get sorted quite well enough.

[JonB_in_Glencoe]

Future generations my have to learn to cast straight zinc. Not much new lead coming these days.

I don't think any "new" lead has arrived since creation ;)

[Wayne Smith]

I don't think any "new" lead has arrived since creation ;)

Since lead is completely expired uranium - yes, there is a little new coming along constantly.

[dtknowles]

I don't think any "new" lead has arrived since creation ;)

New lead is created every day.

Radioactive decay to lead

Frequently, the quantity of uranium 238 and lead 206 are measured for radiometric determination of the age of rocks. The half-life with which uranium 238 decays to form lead 206 is 4.46 billion years. After 4.5 billion years (the alleged age of the Earth), at least the same quantity of lead and uranium should therefore be present on the Earth's surface. However, in reality, there is more lead than uranium. It could be assumed that an undetermined quantity of lead 206 formed directly when the rocks originated. Moreover, in addition to uranium 238, 52 other elements also decay to form lead 206. The half-life of these elements varies between a few microseconds and 245,500 years. It is therefore not possible to estimate how much of the lead 206 present today actually originated from uranium 238.

[JonB_in_Glencoe]

well, I ain't seen any of this "new" Lead, so I'm thinking it's FAKE NEWS :veryconfu

[josper]

thanks for your input. I learned something new. I still cling to the old ways and try my darndest to keep zink out of my alloy. I hand-sorted my wheel weights and when melting I pay close attention to any floaters which get skimmed off before they can melt. I mined the berm just before the club had moved the berm to extend the range. I ended up with close to 800 lbs. I probably will never have to do that again. I got a little carried away with casting my 45 boolits and I gave away some to my buddies that reload. one of them has a nice sharps that he loads for. another has one of those old carbines with the trap door,45-70. I gave him enough to keep him shooting for a couple of years, lol.

[bangerjim]

I've cast up to 5% Zn for tests and have seen not problems. Boolits are a tad lighter and it takes a little more heat to get perfect drops, but as the "sages of olde" kept saying for generations......."one zinker in a melt and you throw the whole thing out." Totally wrong.

Cast away and don't worry about a few % Zn in your melt.

Some cast pure Zn boolits!

banger

[hodg0610]

This is interesting. I had always thought zinc would somehow ruin the pot and the molds, not just the mixture. I might have to give this a try.

[bangerjim]

This is interesting. I had always thought zinc would somehow ruin the pot and the molds, not just the mixture. I might have to give this a try.

You will not ruin your mix...................and CERTAINLY not your molds!!!!!! Many decades ago, that old wive's tale got started about a "teeny bit of Zn will ruin everything" because people got wrinkled boolits with a known Zn %. Wrinkled boolits are generally caused by just a very few things............low temp alloy, low temp molds, and novice casters. That's it. Not oil, not grease, and not Zn. And if there is Zn in there, you simply need to goose up the temp of your mix a bit and make sure your preheated molds (on your electric hotplate.....you DO use one, RIGHT?) are a bit hotter than normal.. Frosty boolits (if you do get them) are not bad. If you do not like them, just slow down your casting speed a tad and/or lower your alloy temps.

And adding a little more Sn will help also.

Good luck casting. If you ever get the urge to "throw a whole pot out" just because of a little Zn contamination, just cast it up into ingots and send to me! I will pay the USPS charge for the box. And I will gladly cast boolits with it.

[GregLaROCHE]

I would never consciously add zinc to my casting pot. However, if some accidentally gets in, can’t you flux it out by lowering the temperature, until it starts to congeal and rise to the surface?

[bangerjim]

I would never consciously add zinc to my casting pot. However, if some accidentally gets in, can’t you flux it out by lowering the temperature, until it starts to congeal and rise to the surface?

You would have to have a LOT of it to do that! And you will be scraping off most of your Sn and Sb by skimming and throwing it away.

Just do not worry about a small amount of Zn. Your best way is to do a very good sort B4 you ever melt anything.

But try it and see if it works for your needs. I never worry about Zn anymore. Haven't ever since I did the research on up to 5% Zn contamination. Just adjust the temp and cast away.

[Baltimoreed]

My first experience with zinc wheelweights was when I bought some ‘lead’ weights from a guy years ago. When I saw the box and felt the weight I thought this isn’t right. Turned out 3/4 was zinc 1/4 lead, when I contacted the guy he claimed he didn’t know-didn’t want them returned but did refund some of my money. I keep meaning to carry them to a tire place to see if I could swap them for lead. I had never heard of them living in NC. Live and learn.

[dondiego]

I have had a serious case of zinc contamination in one of my melts. I just kept adding known, good wheel weights until the melt straightened out and poured real nice. I might have increased the temp, I can't remember. It happened to me at about the time when zinc weights had just started up. I had never heard of them. Well, I melted some into my melt. It was thick but I just kept diluting it and it turned out fine. It didn't take too many pounds in a 50 pound melt.