Willy Snyder
PO Box 2732
Pocatello, ID 83206
Greetings, don't post much but have a question.
Using wheel weight, keeping temp about 650, Why do my
38/357 boolits come out very large?? Supposed to be .358 getting .363 some 365??? Seems like a lot &
not nice running them through a sizer?? Gonna toss 'em back in the pot.
Any & all info greatly appreciated....
Big difference. First question is have you used this mold previously and did they come out close to 0.358? If yes, I had this happen once and it turned out I had a little lead that had gotten stuck to the surface where the two mold halves meet. This was holding the mold halves apart just enough that they would still cast but to the wrong size. If the have never come out at 0.358 the mold might be bad.
Hick: Iron sights!
Hello LarryW, Check to make sure that there is not any specs of lead on the mold blocks. Close the mold and hold it up to the light to see if there is anything inbetween. Also sometimes there can get specs of lead in the slots where the handles go. Also, sometimes the handles just don't close all the way.
I usually run my wheel weights around 750 to 800F
Which mold do you have?
Could you post some pictures of the molds and your cast bullets?
Are the bullets the same when measured from different points? Like on the parting line and 90deg from the parting line?
Exactly what mold does the OP have? A picture of the block ID stamping or of the original box would help.
.
Originally Posted by PositiveCaster
So would casting alloy. Pure lead will cast vastly different size boolits than Lyman #2
“Cui prodest?” Lucius Annaeus Seneca
800F degrees or more, will allow more shrinkage, as bullets cool.
Frosted bullets from an iron moild will be smaller in diameter.
Less % antimony, smaller as cast diameter.
Higher temp will shrink more. Antimony/tin in the mix will shrink less. It's easier to size them smaller than to size them larger.
Your casting temperature is too low. Try using around 750 degrees. You don't want to get the alloy too hot or it will start to oxidize, so around 750 degrees should be good. Check your mold to see if it is closing completely. Close the empty mold and hold it up to the light. Look through the sprue holes - you should not see any light between the mold blocks. If you do see some light find out what's keeping the mold from closing completely and fix that.
Very rarely will you get a mold that throws a bullet exactly the size indicated. Alloy & casting temps affect final size quite a bit. Of you are using a multi cav mold, good chance they all wont be the same size as cast. I cast any alloy about 725 deg. Agree, check the mold faces for any irregularity that would hold them apart.
EVERY GOOD SHOOTER NEEDS TO BE A HANDLOADER.
NRA Cert. Inst. Met. Reloading & Basic Pistol
What make of mould?
Larry Gibson
“Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
― Nikola Tesla
I second this question. My Lee molds generally tend to cast bullets way over their nominal diameter. .358s dropping at .362 or larger is not uncommon. Not as much a problem with MP, NOE, etc.
No matter the make of the mold or alloy, If it is that big out of a 358 mold them either the mold was modified or lead between the blocks. a .005.008 difference is a mechanical problem
Not necessarily. If he's using a Lee 6 cavity and holding the sprue lever when pouring such oversize bullets are common. Additionally, if the mould was made by for a different alloy or a custom diameter such oversize bullets can be the result. That's why I asked what make mould is being used.
Or, as mentioned, there is something on the mould face keeping the blocks from closing correctly such oversize bullets can be the result. There have been numerous "group buy" moulds, especially for handgun bullets, made to cast larger diameter bullets to fit perceived oversized cylinder throats. A couple of the custom mould makes have also made such and offer them for sale now as cataloged items.
Larry Gibson
“Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
― Nikola Tesla
harder bullets cast larger than softer..but weigh less.
.005 to .007 is way to large
something is wrong with your technique (holding mold handles) or something mechanically wrong with your mold (specs of lead on mold face or protruding alignment pin).
~~~~~~~~~~~~~~
“If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun.”
― The Dalai Lama, Seattle Times, May 2001
Hello folks. Sorry for the long time of not answering back but, as we all unfortunately know,
Sometimes, life happens!!! Anyway...
Everyone, thank you all for your time & great answers, Much appreciated, much learned!!
I found I was not holding the mold solid closed?? Bad arthritis, just kind of let the handles lay in my somewhat closed hand? Thought they were closed?? So, found if I squeeze just a tiny bit, all good.
Using old Lyman, Ideal & Lee
Once again,, Thank you all. PS..
You know, so many folks on other sites moan & groan & bitch about Cast Boolits????
I don't understand any of them, unless they were starting trouble or scams!!!!
I have been treated with NOTHING but respect since I first joined & started casting?
Just don't get it????? Thanks again... Take care & be safe...
Thanks for the update and glad you found the problem .
I'm sorta having the same problem ... Hands and fore arms get tired ...giving out before I'm ready to stop .
I can't cast as long as I used too .
I now Cast in shorter Sessions and I try and rest my arm on something ...
anything that takes the weight off , that helps ... I also change hands ... cast left handed for a spell ... try anything that takes the weight off your hands and arms .
Two Cavity Lee moulds help with weight but my favorite are Three Cavity alumn. moulds made by NOE ... not many make 3 cavity moulds but they are lighter than 4 cavity and produce more than a 2 cavity ...
Try a 3 cavity mould if you can find one !
Just Keep On Keepin On
Gary
Certified Cajun
Proud Member of The Basket of Deplorables
" Let's Go Brandon !"
Buffalo Arms offers a couple mold handles that lock the mold together.
https://www.buffaloarms.com/steel-mo...cthandles.html
~~~~~~~~~~~~~~
“If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun.”
― The Dalai Lama, Seattle Times, May 2001
I am with Hick on this one.
Ain’t it funny how as we age we have to change how we do things……actually I’ve changed from quickly getting out of bed to grumbling and groaning as I try to reposition all of my bones
Last edited by Echo#154; 08-01-2026 at 01:30 PM.
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