Mold Material

Lee S. Forsberg

New Member
What's your preferences and why?
I like cast Iron.
For, holds temperature more consistently.
Against, takes longer to get to cast temperature, particularly with small caliber bullets.
Thanks
Lee
 

Bisley

Active Member
I got started with iron -- pearlitic copper alloyed cast iron (SAECO, I think); lead alloyed iron (Lyman, I think); whatever RCBS uses, etc. I like the weight, heat retention, and handling because that's what I got started with. No, I am not going to bash Lee, but I had a .457 RB aluminum mould from them once, and it wore out (I got dies, priming tools, and a pot from Lee, but not their moulds) . Then a professional bullet caster from Anchorage, whom my Dad and I met on the range, told us that aluminum Lee moulds were great and economical (true), but would do that. For the time involved in shipping, and extra cost to AK, I decided on iron. I've never had an iron mould fail or wear out in normal use; they take repair, surface rust and storage considerations not withstanding.
 

Bret4207

At the casting bench in the sky. RIP Bret.
#1 on my list is the brass or bronze my sole Yankee mould is made of followed very closely by the iron/steel my H+G 10 cav is made of. After that it's a toss up between Lyman/RCBS/SAECO/Hoch and the Lee type aluminum. There's nothing wrong with aluminum, but OTOH, there's not a lot to make it "better". I think the quality of the individual mould can make or break how much I like them. A really good Lee type is easier to use than a poorly cut iron type. Heat retention I can control via casting tempo, it's not a major factor to me.
 

Petrol & Powder

Well-Known Member
I have Aluminum, Iron and Brass molds; more iron than anything else. They all have their pros and cons, but I must say that I favor iron.
The mass of iron holds heat well. The iron is less likely to get scratched or dinged. And the material is very tolerant of the thermal loads we place on molds.
The downside of iron is the weight and potential rust. Not much you can do about the weight, but a 4-cavity mold isn't too heavy and is a good compromise of size/weight/speed of production. Preventing rust is simply a matter of self-discipline. Iron requires some dedication to storage and de-greasing, but it is a price I'm willing to pay.

Brass has most of the good qualities of iron and it will not rust (well the blocks will not rust, the sprue plate and hardware can). The downside is cost and weight. Again, a 4-cavity is about the right compromise in size/weight.

Aluminum is certainly the lightest and generally the least expensive. I wouldn't call aluminum molds fragile but if you're going to damage a mold; an aluminum one is the most likely to get damaged. Rusted blocks are a non-issue with aluminum molds (again the hardware is still vulnerable).

For me - Tools are generally a "Buy it Once" activity.
 
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Winelover

North Central Arkansas
Almost fifty years ago, my first mold purchases, were RCBS (iron). Next up were brass (MP). Finally, aluminum from custom makers. My last mold purchase was a iron four cavity from Accurate. Went full circle and returned to what I learned on and prefer.

Iron molds are the least fussy and most durable. IME

Rust is a non issue, if stored with desiccant packs in airtight containers.

Iron molds, in terms of weight, fall somewhere between brass and aluminum, given equal number of cavities. Anymore, three or four cavity molds are perfect for my usage.
 

CWLONGSHOT

Well-Known Member
I started with a single cav 38 Wad cutter IDEAL. Was probably 15-20 years before I had a LEE Alum. But my Fav by a good margin is Brass. Yea its heavier, but the way it regulated heat is second to none. I also see a difference in "IRON" molds. H&G cast different then Saeco then Lyman.

CW
 

RBHarter

West Central AR
I have and have had some of the purported best moulds available .

I have currently a broad selection of iron and aluminum moulds and 1 MP brass nose pour PB/HB .
Aluminum moulds are from Lee , Rapine , NOE , Mountain , and I've had a couple of LBTs . Lee is a tool for a job and it does the job most of the time . Guilty confession in 40 cal for the 40 Smith LBT and RCBS gave me nothing on paper or Chrono I wasn't getting from the 6c Lee so they're not here anymore . Lee also doesn't offer all of my wants .
NOE has been the best cash per value to me so far for new moulds .
I'm a little bit sad that I didn't buy more Mountain Moulds when I could the 2c .453-350 RNFP is stellar . Of course it's perfect where it was intended .
Rapine was a used mould for a dimensional want and it's not a bad mould . It doesn't seem to have all of the faults often pinned on them .
The LBTs were nice moulds and worked well but we just didn't click , I may have expected more from them or maybe the sprue plate was off putting ...... Both have new homes .

Iron moulds . Lyman etc , RCBS , Cramer , Herters , H&G , Ohaus , Lachmiller and at least one more I've forgotten ......
The Ohaus didn't stay long , pig in a poke 54 cal SWC . I cast one of the 2 just to see what it was .
The others well their iron moulds . I'm not terribly attracted to the Lyman 4 hole but it's on clam shell handles and a 257312 so that's part of it I think .
The H&G is everything it's said to be and with a 1992 price of $225 it better have been . It's also 8 holes .
The others are singles and doubles cast easy and hold well , the older ones are well scaled to what they make .

Brass . I was initially very let down , 20 sessions later I can see the hype of both brass and MP .

I haven't bought a new mould in 6 years but I will say if I'm going to spend $90-110 on a single or a double it would be a toss in iron or brass .
If I were only buying for production without a particular design need I think I would spend the double on NOE over Lee .
I don't see iron or brass being a thing here again unless I can buy another $30 8c H&G in a desired shape .

Pros
Cost aluminum wins
Weight aluminum wins
Production aluminum wins
So far I really don't have a problem with run out in aluminum against production and cost . Only 17 yr in the game though .
Iron and brass win for consistent singles and doubles excluding semi/custom aluminum .

Cons
Aluminum life . I don't see this as a problem for me personally but the Lee 2 C 452-255 did show it's miles around 5500 cycles so I replaced it with a 6 c .
Brass and iron are heavy not so much in scaled singles and doubles but "modern" 3 blocks for everything moulds are heavy and quads plus are just tanks to work with , so weight is a con for me .

Reliable accuracy ....... I don't know if that's an iron con or not I've been lucky I guess and I don't want to let one example drag down a whole class , but aluminum hasn't showed me that at all .

At the end of it all singles and doubles iron and brass are a dead heat but the 462-420 brass is a little heavier than I'd like .
I love the 8c H&G but I could do without it's 8-9# on the other hand at 3 pours per lb in 45 pours it's time to refill the pot and there's 300+ keepers in the bucket .
I hate the 4c Lyman 257312 it's hard to get hot and keep hot , it's also on large blocks so it weighs about 5# .

NOE 3,4,5 Cavs have been stellar from 225-37 to 460-543 .
Heat retention I struggle with a little under 25 cal .

I guess in all it's as much about goals as weight . Once you have technique and designs that are working volume vs weight is the only real contest left unless you need over 30,000 bullets .
 
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Red Bear

Member
aluminium is my favorite only because of weight. other than weight i think brass is best for me. not sure brass is better or my brass molds ( mp )are just better molds.
 

Brad

Benevolent Overlord and site owner
Staff member
I like them all. I own more aluminum than anything. Like the light weight. Brass casts very well and you get in an arm workout too.
Been a while since I used an iron mould.
 

Rockydoc

Well-Known Member
MP makes high quality molds, but they are my least favorite because they are brass and very heavy. If I didn’t have arthritis so bad in my right wrist I might feel differently about brass molds.
I don’t have trouble with 6 cavity Lee aluminum molds. I haven’t compared weight of th 4 cavity brass to the 6 cavity aluminum but I wouldn’t think there would be much difference.

I have only a few iron molds but they are 2 cavity molds and a delight to cast with.

I am having surgery on my right hand next Tuesday. Carpal tunnel and “trigger finger “ release procedures. There is so much damage to the bones of the wrist I am not expecting much relief in that area. Just something to keep things from getting worse.
 

david s

Well-Known Member
I've got to fall in with Rockydoc, as time goes by, I begin to appreciate aluminum moulds more for their lack of weight. Still have some brass and some Lyman/RCBS iron moulds but I've either sold or given away quite a few of the iron moulds. And it's not like the bullets cast in an aluminum mould are some sort of compromise there fine. As RBHarter mentioned the NOE 5 cavity aluminum molds have to be about the best deal going, even beating the Lee 6 cavities. Simply better quality.
 
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Jeff H

NW Ohio
I'm going to say that my personal preference has finally shifted to aluminum.

I grew up on iron and still have them, almost all single-cavity moulds, a couple 2Cs, and they all did a great job. These were my dad's moulds and he turned them over to me several years ago, but in the interim, when I wasn't close to home, I ended up buying a few aluminum moulds and learned to use them. They were cheap and cheap was a major in the criteria category at the time.

I ended up with a couple 6C aluminum moulds just to get the bullets I wanted and got the hang of those, pretty much.

Once I discovered the custom mould makers, I ordered aluminum, because I liked the volume of the 6C and the weight difference was pretty significant, besides I was used to using aluminum by then. Now, I order 4C aluminum moulds when I want something, because the 4C is a good weight with great production, and I never have to clean the blasted oil off them before using them. I put them away as-is and they are ready to go the next time.

I only ever had one iron mould rust on me, and it was a fluke. I've cast my 429421s from the same 1C iron mould for as long as I can remember, and it got used EVERY time I cast so I could keep up using that slow-poke 1C. I never had to oil it because it never got rusty in the defunct freezer I store them in, but it was a horrific sight when I pulled it out one day and saw RUST all over the insides. I got it cleaned up, but the aluminum won't do that.

I can get interrupted in the middle of anything and I have to drop what I'm doing and take care of things. This is ithe main reason I don't shoot my muzzle-loader any more too. Maybe if I had leisure time I could plan, I'd still use iron, but the aluminum 4Cs are easy to handle for an hour or two at a time and I do like that. They do cast just as nice a bullet as my old iron too.

A few of them say "LEE" on them, but I won't lie - I've had some stinkers. The ones I do have were the only choice for THAT bullet at the time I bought them. None of my moulds were made in China, if that means anything.;)

If I hadn't had a LEE mould to practice "de-gas-checking" on, I'd have never had the guts to do it to one of my custom-maker's moulds.
 

Bret4207

At the casting bench in the sky. RIP Bret.
Yeah boy, nothing like opening the old dead freezer up to find out rust has hit your moulds. I'm still working on that issue! There is something to be said for aluminum in that respect, but brass has the same features- and costs more. Pluses and minuses.
 

CWLONGSHOT

Well-Known Member
All my molds in rotation, get a coating of mineral oil after use.

A good friend submerges his long term storage molds in single weight gear oil.

Mineral oil works well for me but Im not badly troubled by rusting issues.
 

smokeywolf

Well-Known Member
Can't knock aluminum moulds, never owned one. With the exception of one brass mould, all my moulds are iron; most being old IDEAL.