How much over sized are moulds?

[Shadow9mm]

Ok, I m hoping to get set up to start casting next month (august 2021)

I'm planning on the Lee mould's so I can tumble lube, just easier and faster starting out.

I am planning to cast for 9mm and 38/357

I only have calipers, but I slugged the 9mm barrel at .356

and for my 38/357 a .358 bullet will pass through the cylinder throat, a .359 bullet will not

So as I understand it I will need .357 for 9mm and .359 for 38/357 for a proper fit.

If I order moulds in .356 for 9mm and .358 for 38/357 they will be over sized right? And I will need to size them down? how much bigger will they be? will I be able to size them to .357 and .359 or will them be too small coming out of the mould?

Really appreciate the help. It has been a bit of a learning curve, especially with the revolver.

[ballardw]

Quite often you'll find that metal content affects size as dropped after cooling.

This link has one shrinkage chart as an example and includes .357.

You want to check the makers recommendations or actual mould size.
Some moulds and alloys may not need any sizing, others yes depending which actual diameter you want.

May want to jump over to http://castboolits.gunloads.com/ if you haven't been there yet. You may get answers regarding specific moulds and alloys.

[USSR]

If I order moulds in .356 for 9mm and .358 for 38/357 they will be over sized right?

Don't bet on it, particularly if you buy a cheap over-the-counter mold. Ordering from a custom mold maker is a different story.

Don

[Shadow9mm]

Originally Posted by USSR

Don't bet on it, particularly if you buy a cheap over-the-counter mold. Ordering from a custom mold maker is a different story.

Don

Most of the customer makers are sold out on everything. that is one of the other reasons I was looking at lee. they are available.

[Shadow9mm]

Originally Posted by ballardw

Quite often you'll find that metal content affects size as dropped after cooling.

This link has one shrinkage chart as an example and includes .357.

You want to check the makers recommendations or actual mould size.
Some moulds and alloys may not need any sizing, others yes depending which actual diameter you want.

May want to jump over to http://castboolits.gunloads.com/ if you haven't been there yet. You may get answers regarding specific moulds and alloys.

Just signed up. I have a LOT of learning to do.

[USSR]

Most of the customer makers are sold out on everything. that is one of the other reasons I was looking at lee. they are available.

Custom mold makers are never sold out. They only make them after you order them. Sure, you have to wait a few weeks to receive the mold, but you will not receive a mold that drops under size bullets.

Don

[Shadow9mm]

Originally Posted by USSR

Custom mold makers are never sold out. They only make them after you order them. Sure, you have to wait a few weeks to receive the mold, but you will not receive a mold that drops under size bullets.

Don

Any recommendations?

The only one I have found so far is accurate moulds but they are 100 for a 2 bullet aluminum mould vs 30 for a lee. And iron is in the $160 range. They also want to know the specific alloy that will be used, and I don't know that yet.

[USSR]

Shadow,

There is simply no comparison between a Lee mold and an Accurate mold. All of my Accurate molds are brass (except 1) instead of aluminum or steel. Think of this as a lifetime investment, not something to get as cheaply as possible. This is where brass or steel pays for itself; both hold up to prolonged use MUCH better than aluminum does. Regarding the alloy, I would suggest you select "COWW + 2% tin". It will handle both the 9mm and .357 loads, and if you want to use something a little softer for .38's, the bullets will come out just a little bit heavier and smaller, but with your Accurate mold dropping bullets .002" over with the specified alloy, it would probably drop them somewhere between .001" and .002" over with the softer alloy.

Don

[Targa]

I would suggest reconsidering a two cavity mold simply from an output perspective. As for Lee, they work great and their tumble lube designed molds are perfect for just that.
You can pickup a Lee six cavity and and handles for around $65. If you are just wanting to get a feel for casting the Lee two cavity is a great way to start. The dozen or so Lee molds I own cast at least .001 over the advertised dimensions but as already mentioned the alloy you use, the temperature your casting at, rather or not you are air cooling or water dropping your cast etc etc can all influence the size of the bullet.

This is a good video to explain it in a nutshell
https://youtu.be/3GTTeXHVYWc

[DukeConnor]

Lee states you probably won't need to size your bullets. But as has been stated, it depends on your alloy. I've had great success with lee moulds. And they are readily available. The lee sizing kit is pretty inexpensive also.

Go for it and enjoy.

[jaguarxk120]

There is good reason some mold are sold out and some are in stock!

Custom molds cost more, try looking at SAECO molds made by Redding.

[armoredman]

I honestly can't say how "oversize" my molds are, (Lee and NOE), because I just automatically run them through the sizer after powder coating. I wouldn't load an unsized boolit, (CastBoolit spelling here), so that really never bothered me. My NOE mold drops at .314 and I size it down to .311 with a standard Lee Push Through sizer for both 7.62x39 and .308 with no issues.

[Shadow9mm]

So to start out I am going with the lee moulds and powder coating. Even if the moulds are under sized for my needs the powder coating should bump them up a bit. It will also let me play with alloys a bit to see what I want to use so I can properly order a custom mould later down the road.

[Targa]

That is a good way to go.

[gwpercle]

Originally Posted by Shadow9mm

So to start out I am going with the lee moulds and powder coating. Even if the moulds are under sized for my needs the powder coating should bump them up a bit. It will also let me play with alloys a bit to see what I want to use so I can properly order a custom mould later down the road.

There is nothing wrong starting out with Lee moulds , they will let you get your "feet wet" without breaking the bank . Order a mould for 9mm Luger and one listed for 38 special , the as cast diameters will usually be fine in these calibers (45 Colt is the trouble maker) , powder coating will increase the size and you can always size them smaller if need .

I was buying my first 9mm Luger mould and used ( bought) 4 different 2 - cavity Lee moulds to determine what I wanted was a .357 - 124 grain truncated cone gas check mould ... which I ordered from NOE in a 4 cavity version ... I could never have done that if Lee moulds weren't affordable . That was my first NOE mould and they are sweet ! But the Lee moulds let me try : 102 gr. rn , 105 gr. swc , 120 gr. tc , 125 gr rn and figure out what worked best ...it was Truncated Cone around 120-124 gr, weight !
Gary

[FrankenMauser]

Lee molds typically drop a couple thousandths over stated diameter. Sometimes, they drop notably larger, and/or out of round.
For example, if you bought a .359" mold, I would expect the bullets to drop at .360" to .361". But it is well within Lee's typically quality level for them to drop at say, .359" x .363" -- out of round.

Accurate Molds makes a far better product. Materials are better. Tolerances are better. Longevity is better.
But one major factor to keep in mind is that Accurate's entire catalog is custom designs. They are not standard bullets. Even if it is a common design and based on a popular, established cast bullet, the design in the catalog was submitted by a person that had a specific application.
Just because "it's a 9mm bullet" doesn't mean that it will be a good 9mm bullet for your application.

At last count, I believe I have 21 designs in the Accurate catalog. Some were for my own amusement or experimentation, some were special applications, some were for other people and their special applications.
Not one of them is very useful outside of the original application. Some *could* be used by the general public for certain common applications, but other designs would be a better idea.


I do not think it would be a bad idea to get your feet wet with Lee molds and go from there.
Learn what you can. Learn what matters. Learn what you need to know before upgrading to a better mold.

The overwhelming majority of my molds are NOE - whether production molds, group buys for molds that fit my needs, or group buys where I had some influence on the bullet's design.
And I have a fair number of Accurate Molds and Mountain Molds (out of business now).
They're good molds and I like them.
But I also have Lee molds that get regular use when I am casting. (Comes in fits and spurts every few years.)

[Unclenick]

All the mold designs and materials have different advantages. For aluminum, thermal conductivity is a plus. It is about two-and-a-half times greater than brass and five times greater than iron. This makes it easiest to heat quickly and uniformly. Brass is the easiest to machine with high precision. Iron is toughest. Aluminum will also cool the fastest, so it demands the most consistent production rate to keep the temperature even. It also has the highest temperature coefficient of expansion, meaning it will change size most with temperature, where iron changes the least of these three materials; less than half as much as aluminum. The practical consequence is an alloy that casts a hundred degrees hotter will make an aluminium 35 caliber cavity about half a thousandth bigger, while iron will be only about a fifth of a thousandth bigger. This is before considering how much the casting alloy itself shrinks as it cools.

Personally, I like the tumble-lube designs. I got one of the Lee six-cavity molds for 148-grain wadcutters for my K38. In alloy about like Lyman number 2, they cast 0.3585", and compared to any of several brands of commercial match 148-grain wadcutter ammunition I've tried, the groups I get from them are half the size. I shoot them as-cast. Letting the gun do the sizing is a successful time saving step, and seems to produce less leading than sized bullets do. I haven't powder-coated them as they shoot so well that I don't want to change the diameter or start sizing them to accommodate the coating thickness. Plus that adds two steps. The penalty is some periodic lead cleaning, but it's not bad, given the modest target ammo pressures involved. Shooting them without lube seems to work just fine, as long as the bore is smooth.

[Mike / Tx]

So far hard to beat the advice already given. That said I'll add that I have a multitude of Lee molds in various calibers.

For the 9mm I like the 6 cavity 356-120 TC & 356-125 2R. Those both shoot great out of several pistols and can be lubes however you feel up to doing it. The Lee .357 or .358 sizing dies work great.

For the .38 cal, I really like the .358-125 & 158 RF in the 6 cavity versions. Same as above they can be lubed however you feel you want to do it. I've shot all of the listed TL'ed, conventional, and powder coated.

Most of the alloy I use starts off as around a 1/3/96 or thereabouts. I blend in some tin and/or pure for HP'S but usually pour my solids with it straight. I air cool everything so as to try and keep the BHN on a good average.

To date with both calibers, and using Carnuba Red and PC I have run all of the above bullets to top end velocities with no ill effects. Your milage may vary.

[Mike / Tx]

Duplicate post....oops