DIY mold making.

[mooman76]

So with the Lee if you take care of it. I have Lee moulds that are at least 50 yr old. I agree though, I would at least use a better grade of aluminum. I have some TC moulds, aluminum and they are very well made.

 

[springfield art]

Who here makes their own molds?

I recently made my first proper mold and I've learnt quite a few things in the process. If there is interest I'll describe it in detail. I would like to also hear any tips other people learnt when making their own bullet molds.

Here are few pictures.
The cutter before being heat treated:
View attachment 89302

And after the first test cut (what's left of it) :-(
View attachment 89303
Not to worry, enough of unhardened shank was left to machine another one. This time with better relief angles.

Here it is making a cut in the mold blocks.
View attachment 89304

Mold blocks were made with 7xxx grade aluminium rod. 2in diameter. Flats and other features were milled, surfaces were surface ground.

I borrowed a sprue plate from a Lyman mold. I initially planned to use lyman handles, but I ended up using Lees as they work better with long blocks like this one.

Here is the mold completed.
View attachment 89305
And during use
View attachment 89306
Results
View attachment 89307

Those bullets are 0.612 for an original rifle I have.

Hey wow! Interesting! Thanks.

 

[excess650]

I have not ventured into mold making as of yet, but I do possess the engineering and machining background to accomplish the whole process. Aluminum would be my last choice for block material, an appropriate cast iron would be the thing. You can buy a cast iron Lyman, or an aluminum Lee, among others. The difference is that the Lyman will still be with you in 50 years.

Lyman mould blocks are steel, and most likely 12L14. Saeco and RCBS use a variety of meehanite. Aluminum actually makes excellent mould blocks if steel pins and sockets are used for alignment.

 

[Ironoxide]

I have not ventured into mold making as of yet, but I do possess the engineering and machining background to accomplish the whole process. Aluminum would be my last choice for block material, an appropriate cast iron would be the thing. You can buy a cast iron Lyman, or an aluminum Lee, among others. The difference is that the Lyman will still be with you in 50 years.

I haven't made that clear, but this mold is just to test a design and the diameter. It is not meant for permanent use. However, it being made from aluminium has nothing to do with it.

I have no problem with aluminium as the material of choice. I have a number of commercial made (Lee) aluminium molds I'm very happy with. I also have commercial molds made of cast iron, steel and brass so I think I have a fairly good grasp of how they differ.

As long as one is gentle with it, and uses proper lubrication aluminium is a very nice mold material. It is very quick to heat up and cool down so it allows one to cast a lot quicker than let's say cast iron or steel. In fact one has to be careful with iron/steel molds too. Once I damaged a guide socket in a lyman mold by slamming it shut too hard. Aluminium however has a tendency to gall in contact with steel of the sprue plate. The best solution for this galling if it happens with for example Lee molds is to take a q tip and put just the tip in fully synthetic two stroke oil. Let the q tip soak that two stroke oil in. Then heat the mold to normal casting temp by putting a corner in molten lead. Remember to preheat the sprue plate too by submerging its corner too. Then open the sprue plate so you have access to most of underside and "paint it" with the q tip soaked in two stroke oil. If it smokes you're doing it right. Once you painted the entire surface, turn the q tip around and wipe all the oil off. If there is any shiny surface, you left too much oil. You have to wipe all of it off. Then try how it runs.

If you're repairing a mold that's already galled you need a very fine flat stone. Then you have to stone both surfaces. Clean them properly to avoid possibility of any abrasive staying. Then heat it up and apply the two stroke oil as described.

I chose aluminium, specially 7xxx because it machines beautifully. It is one of strongest aluminium alloys, machines great with hardened steel. Its only disadvantage is that its non weld able and non-magnetic so I can't use a magnet to hold it on a surface grinder.

My temporary mold has few deficiencies that will be corrected in the permanent mold. The most important is that guide pins are not hardened and there are no steel inserts in guide holes. It is quite possible it will become loose after a while. However, with hardened pins and bushings it will be pretty good in my opinion.

I only ever heard of Lee blank blocks, but none of the shops in EU have them in stock. The only shop in US that does that I know of doesn't ship internationally because of covid :-( That's why I made my own.

In future I'll explore making molds with free machining steel(like lyman's) but for some reason again it is a real pain to buy in EU. I have suppliers that will sell me countless varieties of tool steel, but no one has free machining steel or ductile cast iron :-(

 

[4575wcf]

I stand corrected sir. I would go with the meehanite cast iron in preference to all other materials. Nothing as unstable under heating and cooling as aluminum is in general is going to make anything but a passable mold block. One other option I would like to try is soapstone blocks, properly and accurately mounted in sturdy wooden frames with wooden handles. Too soft for any real rough handling, but heat stable and then some.

 

[Ironoxide]

I stand corrected sir. I would go with the meehanite cast iron in preference to all other materials. Nothing as unstable under heating and cooling as aluminum is in general is going to make anything but a passable mold block. One other option I would like to try is soapstone blocks, properly and accurately mounted in sturdy wooden handles. Too soft for any real rough handling, but heat stable and then some.

Could you elaborate on this instability, please? Do you mean it has high coefficient of thermal expansion? That can be easily compensated for. Or do you mean something else? I'm genuinely curious.

 

[4575wcf]

Well Aluminum gets hot fast, and it gets cool fast. It expands when it gets hot and it contracts when it gets cool. That means your cavity is changing a bit all the time. Meehanite is doing the same thing, just over a much slower and a more balanced curve. I have had poor luck with Lee molds, and I have owned several. I bought the Lee .526 round ball mold for my plains rifle, shot if for years. When I got the opportunity to buy the Lyman .526 later I did. The group shrank 3 MOA immediately. Turns out the Lee round ball was never really round, but it never occurred to me to check it, I just thought I bought a lemon of a barrel. I still use that Lee--to make split shot for sinkers.

 

[Gordoncourtney]

I have not ventured into mold making as of yet, but I do possess the engineering and machining background to accomplish the whole process. Aluminum would be my last choice for block material, an appropriate cast iron would be the thing. You can buy a cast iron Lyman, or an aluminum Lee, among others. The difference is that the Lyman will still be with you in 50 years.

Wants done advice start with aluminium or brass,

 

[Gordoncourtney]

Well you lucky boys across the pond, the U.K. Plymouth shooting with a pump shotgun by a nutter body builder killing 5 of his family it seems It's all across the papers today , police being blamed for reissuing a shotgun certificate .....people phoning in why do people have to have guns.....radio presenters "Close down clay pigeon clubs why do people need guns" One rifle shooter who started a phone in was soon closed down , mmm commissioner of Surrey police "perhaps it's time to ban all guns only allowing farmers and pest officers to have them ."

While you dear folk argue about moulds making......

...my kids don't like guns the Uk is getting too civilised if that's the word and robbers killers rapists and thugs are treated well as it was their upbringing, their parents fault not theirs. ,!!!!!!! criminals come across the channel and are welcomed by our government as refugees.

And we are not allowed to even hint at protecting ourselves.....these people have human rights you know...

My shotguns were taken away two years ago by two big Plods , The fire arms controls I have known for years nice guys, but plod said "you were overheard saying ". "I'll shoot them next time they rob me." shotguns rifles no more in my life. Gone forever. !!!!!L!

Except air guns and obsolete antiques. Luckily I am 78, Not 22 again last time they took our pistols away....what next Emmigrate. But Australia is just as bad,....

I won't rant on anymore, but protect your right to hold arms.

However

If you are starting out make the moulds out of brass or aluminium, you will make mistakes like me , but with aluminium it's easy to make another and cheap, I use brass occasionally as I have plenty of it......cast iron great for steam engines, but harder to machine without chatter on occasions But it's your mould be interesting to see how you get on.......I would struggle with cast iron on my little lathe, but my big industrial one would be fine, but it gets cold and miserable during the winter months down the garden workshop.

We wish you well from the UK

 

[4575wcf]

Meehanite, ductile cast iron cuts like butter. It is dirty stuff to machine because of the high carbon content, but it cuts accurately. When choosing a bullet mold material it seems we are searching for stability under changing heat conditions. You will find meehanite ductile castings in the bases of machine tools of all descriptions. Properly optically scraped in, such bases, ways, and milling tables are capable of flatness to about 4 millionths of an inch over the length of travel. Beyond that standard, black granite becomes the surface of choice. We see aluminum in the bases of some CNC Routers, and Plasma Cutters. They can be as accurate as to between .003 to .005 over the range of the travel. When aluminum becomes the new standard for machine tool bases, it will begin to make really stable mold blocks.

 

[Ironoxide]

Well Aluminum gets hot fast, and it gets cool fast. It expands when it gets hot and it contracts when it gets cool. That means your cavity is changing a bit all the time. Meehanite is doing the same thing, just over a much slower and a more balanced curve. I have had poor luck with Lee molds, and I have owned several. I bought the Lee .526 round ball mold for my plains rifle, shot if for years. When I got the opportunity to buy the Lyman .526 later I did. The group shrank 3 MOA immediately. Turns out the Lee round ball was never really round, but it never occurred to me to check it, I just thought I bought a lemon of a barrel. I still use that Lee--to make split shot for sinkers.

That's a good enough reason to want a more stable metal. Sure, However, I use a casting technique that ameliorates this problem somewhat.

I have a casting thermometer that shows me the temperature of lead. Every alloy I use has "it's favourite" casting temp. I have a contactless infrared thermometer for checking the mold temperature. Aluminium molds I always heat to 200c, then I let them cool for at least 30s before casting. I also cast with a certain rhythm. I tend to count seconds in my mind almost mechanicaly for each action. I usually listen to talk radio during casting and after few minutes it almost happens on "autopilot"

Then once I have some number of bullets that looks good (20,50 etc). I weight them all and I arrange them on my desk according to weight to nearest tenth of a gram (about 1.5grain). Usually there is one weight most bullets match. All the others go back to the pot.

Regarding your experience with better groups using a Lyman mold. The ball diameter may be a factor. I realise both molds are supposed to be .526, but are they exactly? Even half a thou makes a difference. In my opinion a slight variation of diameter makes a lot more difference to accuracy than out of roundness that is symmetric around the sprue(assuming you load sprue up, if you load without paying attention to where sprue goes I agree out of round will be very bad).

Meehanite, ductile cast iron cuts like butter. It is dirty stuff to machine because of the high carbon content, but it cuts accurately. When choosing a bullet mold material it seems we are searching for stability under changing heat conditions. You will find meehanite ductile castings in the bases of machine tools of all descriptions. Properly optically scraped in, such bases, ways, and milling tables are capable of flatness to about 4 millionths of an inch over the length of travel. Beyond that standard, black granite becomes the surface of choice. We see aluminum in the bases of some CNC Routers, and Plasma Cutters. They can be as accurate as to between .003 to .005 over the range of the travel. When aluminum becomes the new standard for machine tool bases, it will begin to make really stable mold blocks.

I'm having real difficulty finding ductile cast iron to buy in small quantities. I suppose meechanite is not going to be easier, but I'll look for it.

One can argue stability requirements are very different for machine bases (low thermal expansion coefficient) vs mold blocks (predictable behaviour), but hey, if I could have low thermal expansion coefficient I would take it! I'm just saying it is less critical with molds, because it is much easier to control mold temperature, alloy temperature etc.

Gordoncourtney, I heard about the shooting. I didn't realise it was with a shotgun :-(

It is like, when I hear of any crime involving guns on the news here in Poland I hope in my mind "please let it not be a black powder gun" and 99% of the time it isn't. I'm worried if few high profile shootings happened they would try to set up licensing etc. The public are under an impression black powder guns are "less of a danger". Same for smoothbores in UK I suppose. The longer they can think that the better.

I have the same opinion regarding the choice of metals for various things.

 

[Gordoncourtney]

Well you lucky boys across the pond, the U.K. Plymouth shooting with a pump shotgun by a nutter body builder killing 5 of his family it seems It's all across the papers today , police being blamed for reissuing a shotgun certificate .....people phoning in why do people have to have guns.....radio presenters "Close down clay pigeon clubs why do people need guns" One rifle shooter who started a phone in was soon closed down , mmm commissioner of Surrey police "perhaps it's time to ban all guns only allowing farmers and pest officers to have them ."

While you dear folk argue about moulds making......

...my kids don't like guns the Uk is getting too civilised if that's the word and robbers killers rapists and thugs are treated well as it was their upbringing, their parents fault not theirs. ,!!!!!!! criminals come across the channel and are welcomed by our government as refugees.

And we are not allowed to even hint at protecting ourselves.....these people have human rights you know...

My shotguns were taken away two years ago by two big Plods , The fire arms controls I have known for years nice guys, but plod said "you were overheard saying ". "I'll shoot them next time they rob me." shotguns rifles no more in my life. Gone forever. !!!!!L!

Except air guns and obsolete antiques. Luckily I am 78, Not 22 again last time they took our pistols away....what next Emmigrate. But Australia is just as bad,....

I won't rant on anymore, but protect your right to hold arms.

Howeverl

If you are starting out make the moulds out of brass or aluminium, you will make mistakes like me , but with aluminium it's easy to make another and cheap, I use brass occasionally as I have plenty of it......cast iron great for steam engines, but harder to machine without chatter on occasions But it's your mould be interesting to see how you get on.......I would struggle with cast iron on my little lathe, but my big industrial one would be fine, but it gets cold and miserable during the winter months down the garden workshop.

We wish you well from the UK

 

[4575wcf]

MSC Industrial Supply offers cast iron in shapes. The exact grades I do not know. Shooters the world over need to unite. The biggest most monstrous piece of propaganda we ever let slip here in the US was the "active shooter" label. An "active shooter", introduces young people to his sport, competes in events, whether it be with shotgun, rifle, or handgun. He provides back up to his government in time of need, and he respects the police. To call these murderous, self centered, miscreants with a "poor me" attitude, determined to take their revenge on society with some armed attack on unarmed victims "active shooters" is a brazen insult to the rest of us. Who are active shooters.

 

[Gordoncourtney]

That's a good enough reason to want a more stable metal. Sure, However, I use a casting technique that ameliorates this problem somewhat.

I have a casting thermometer that shows me the temperature of lead. Every alloy I use has "it's favourite" casting temp. I have a contactless infrared thermometer for checking the mold temperature. Aluminium molds I always heat to 200c, then I let them cool for at least 30s before casting. I also cast with a certain rhythm. I tend to count seconds in my mind almost mechanicaly for each action. I usually listen to talk radio during casting and after few minutes it almost happens on "autopilot"

Then once I have some number of bullets that looks good (20,50 etc). I weight them all and I arrange them on my desk according to weight to nearest tenth of a gram (about 1.5grain). Usually there is one weight most bullets match. All the others go back to the pot.

Regarding your experience with better groups using a Lyman mold. The ball diameter may be a factor. I realise both molds are supposed to be .526, but are they exactly? Even half a thou makes a difference. In my opinion a slight variation of diameter makes a lot more difference to accuracy than out of roundness that is symmetric around the sprue(assuming you load sprue up, if you load without paying attention to where sprue goes I agree out of round will be very bad).



I'm having real difficulty finding ductile cast iron to buy in small quantities. I suppose meechanite is not going to be easier, but I'll look for it.

One can argue stability requirements are very different for machine bases (low thermal expansion coefficient) vs mold blocks (predictable behaviour), but hey, if I could have low thermal expansion coefficient I would take it! I'm just saying it is less critical with molds, because it is much easier to control mold temperature, alloy temperature etc.

Gordoncourtney, I heard about the shooting. I didn't realise it was with a shotgun :-(

It is like, when I hear of any crime involving guns on the news here in Poland I hope in my mind "please let it not be a black powder gun" and 99% of the time it isn't. I'm worried if few high profile shootings happened they would try to set up licensing etc. The public are under an impression black powder guns are "less of a danger". Same for smoothbores in UK I suppose. The longer they can think that the better.

I have the same opinion regarding the choice of metals for various things.

Thinking I have been a fool we have smashed up so many old machines over the years. And I did not salvage one bit of cast iron for use as a material I could easily have salvaged material with a big angle grinder with all the hard scale already removed tut tut. I don’t make many bullets now and they are sized anyway so alumin or brass is fine for me

I wish you well for your kind words. Ordinary

 

[shorthair]

My admiration and envy of and for you are huge.

 

[Gordoncourtney]

This should be under "burning embers" but we are having a nice family get together here. I live west of London but my pal is in Norfolk 2 hours drive away, he's heavily into guns especially target shooting in excess of a couple hurdled rounds loaded and shot each week.......however he's been persuaded to join a muzzle loading club.
He says ........

One of the members of the muzzle loaders club had an accident with this some time last year - before I joined.

He was taking part in some sort of rapid fire competition with a Brown Bess and the powder charge ignited as he was pushing a wad down on the powder charge. It blew the ramrod through his hand. They've repaired his hand but he doesn't have full function.

Lyman's advice might be to keep the hammer down on the old cap, but that doesn't help with a flintlock.

And as I said above , same club, a priming flask on a bench blew up last week, it's those invisible sparks, as I said the guy was very lucky injuries slight.

I wish you well.

 

[Gordoncourtney]

I am a good engineer, decent machine shop , lathes mills presses, but my pal above uses mainly aluminium moulds, he's almost as old as me, shoots 3-4 days a week as he is now on his own, he's an exceedingly good shot, I used aluminium moulds in my shooting days, so why cast iron , I understand if I was a model engineer I would make it in cast iron, like I made a twin cylinder 3hp steam engine back in the 1970s. And I agree you can pass the cast iron moulds into your grand children,

I heitate to say , or offend, But is it not the material but a poorly made mould, especially in the case of a round ball, which cannot be sized to shape , I think somebody above mentioned cast iron ball moulds. It's possible that a cast iron moulds would elieviate the need to weigh and select bullets after casting, my pal weighs them often but he is a precision often long distance shooter ....well beyond the limits of a muzzle loader

Hot lead will expand and contract far more than a tiny aluminium bullet shape, I doubt if you could even measure it, it's minute, there lies the answer, it's the technique of good bullet casting that counts, not the mould whatever it's made of. In fact later I will heat up a piece of aluminium and report on its expansion and lost it..lets knock this on the head, interesting anyway.

But a pair of Lee moulds is only £22 in the uk...so pull them apart and re machine them......I think it's great that making them in cast iron gives you great pleasure, but a newcomer might get the impression that cheap Lee or aluminium , brass if you like, are substandard usless even, which is not the case. And yes I learnt how to scrape a milling machine table fiat in past ancient days, I still use engineers blue a lot , great stuff,.ok so we did not need a photo

My utter apology for ranting on but us shooters are in a right rage as we are being condemned as not members of a civilised society , as gun owners , after this Plymouth shooting, seems he has a psychiatric problem, his mother wanted him committed, but the police still gave him is guns back........I just muttered "I'll shoot them next time my house was robbed " and Plods took away my shotguns......it was a green and pleasant land , once upon a time.

We wish you all well from UK

 

[Ironoxide]

Gordoncourtney, regarding "burning embers" accident I would be interested to know if he was using any paper in his loads (possibility of burning specs) or anything else that could have left an ember.

Either way I think its good to try to teach new shooters so they avoid putting their hand in a way of possible ramrod launch. I'm not involved in teaching, but if I was I would do that.

I used to load some tight patch/ball combinations normally by putting the palm of my hand on a ball shaped handle I made. After I read all the "burning embers" threads I always hold it in two fingers and rely on ramrod weight rather than force(I made few solid brass ramrods for two guns that need tight loads).

Lee molds are a good starting point. I agree, but I already started making another set of blocks. I need another one and there are few reasons why I didn't go down the Lee mold route.
- I'm interested in finding out if I'll manage to make the second set much faster than the first one. It is usually the case with other diy things for me.
- I can get a double Lee . 562 ball mold for £28($38), but it'll arrive Wed/Thu and by then I hope to be on the range testing
- I want to document the whole process to show others (possibly beginners) how I do it.

So far the most time consuming part is surface grinding.

Regarding, the world in general and our countries. It is very unfortunate, but believe me when I say nothing what you and others describe with regards to public perception happened by chance. There are a lot of resources involved to ensure "active shooter" is a bad word. That guns are portrayed as almost able to kill by themselves and everyone who wants one must be at least a nut and probably a psycho. It is not a new thing either. The ideology that is behind it has been at work since the guns we shoot were the latest technological marvel. Here in Poland we have, shall I say, extensive experience of what happens when this ideology has free reign. We also have other historic reasons why it is a lot easier to convince the public popularity of shooting sports is a good thing. I'll leave it at that as it is not the politics section

 

[Gordoncourtney]

Gordoncourtney, regarding "burning embers" accident I would be interested to know if he was using any paper in his loads (possibility of burning specs) or anything else that could have left an ember

Yes Iron Oxide I have already emailed pal Roy up in Norfolk, however unless he gets a Colvid *** he like others are banned from the ML club, his choice.....he is not happy with the so called *** as many others are. See what comes back...

To you all. I thought I sent this ???????

This is it I just heated up some 1/2" round aluminium bar. In the cold it measured .498 hot .502 heat tested beyond the lead solder melting......I was quite surprised it was that much.....cast iron will be a lot less Well how much is .004 well it's the thickness of one of my hairs, in real terms nothing....so it's clear poorly made bullets are down to poorly made moulds or casting technique not the material the moulds is made from.

As I say I have no argument against cast iron moulds , a beautiful final product, but the years are going by and I haven't the time to wast , the choice is yours, it's your mould do enjoy making it

 

[Gordoncourtney]

To you all. I thought I sent this ??????? As for Ironoxide abovev

This is it I just heated up some 1/2" round aluminium bar. In the cold it measured .498 hot .502 heat tested beyond the lead solder melting......I was quite surprised it was that much.....cast iron will be a lot less Well how much is .004 well it's the thickness of one of my hairs, in real terms nothing....so it's clear poorly made bullets are down to poorly made moulds or casting technique not the material the moulds is made from.

As I say I have no argument against cast iron moulds , a beautiful final product, but the years are going by and I haven't the time to wast , the choice is yours, it's your mould do enjoy making it