Cast Iron, Brass or Aluminium - What is your choice?

[Bad Ass Wallace]

I've been casting for the last 50 years and beside the valuable experience, have accumulated over 120 boolit molds made of all different metals, steel, brass and aluminium.

So what is best? I don't have one preferenced over the others.

Steel molds are great for stability and consistancy; all my precision match grade and lathe bored molds are steel. Once set to casting temperature they can turn out tens if not hundreds of boolits with a variation in weight as little +/- 0.0015 grains. The finished cast diameter is also perfectly uniform.

Brass molds are also good for precision boolts. Faster to heat to casting temperature but also by running alloy a little "hot", can gain almost 0.001" in size due to the difference in the co-efficent of thermal expansion to steel. If having a small break from casting the mold cools more quickly, so you may need to cast some dummies before beginning production once more.

Aluminium molds, such as Lee, heat up quickly but also loose heat quickly if you casting process is not consistant. With molds over 30cal, casting with a 'hot' alloy can increase the finished diameter by 0.002". A good example of this is my Lee 220gn boolit mold for the 338WM, Cast hot it throws 0.3395" boolits 'as cast', perfect for the application.

https://i.imgur.com/28FwQVIm.jpg https://i.imgur.com/azoXSdKl.jpg

[Mal Paso]

Iron is first in my book but MP Hollowpoints only come in Brass and 6-8 cavities in current molds is always Aluminum so It Depends!

I preheat all molds now. Brass 4 cavity and Aluminum 6-8 cavity are hard to start without a warmup.

[bangerjim]

I own only TWO steel 2 cavity molds. That's enough for me. The rest of the "HUGE crowd" is mostly 2 & 6 cavity Lee Al molds and now 12 or so 5 & 6 cavity brass molds. You have not cast with pleasure until you use the 6 cavity HP molds in brass, unlike that single older "bottle stopper" style pictured above. The HP's just rain out of the mold! Very accurate and very repeatable.

Brass does take more heat and stays hotter longer. That is why I am a proponent of electric hot plates to pre-heat all your molds (no matter the material) to FULL casting temp, not just warm, like on the side of a casting pot.

My assortment of brass molds yields excellent precision castings every time. Many of the boolit designs I use only come in 2 cavity Lee Al design, so I have to live with that.

No worry about rust with Al and Brass!!!! Just leave 'em laying in their boxes with no treatment needed.

Any new molds I buy in the future will definitely be BRASS!

Put another shrimp on the barbie and cast away!!!!!!! :drinks:

banger

[Winger Ed.]

I've only used Iron & Alum.
They both work. But I tend to gravitate towards Iron.
I just more comfortable with them, and I think they last longer without having 'issues'.

[Bazoo]

I’ve never used brass. But iron and aluminum both work well. I tend to like iron better. Partly because it holds temp so well. Partly because I don’t have to baby it like aluminum.

[TyGuy]

I still feel like a greenhorn when it comes to casting. I only have two iron molds but I do prefer them over my many aluminum ones. I’d love to try a nice brass mold. I should really buck up and get one ordered.

[barnabus]

iron only for me. never had a Lee on my bench.

[winelover]

Iron, hands down. Most durable but also the most costly. Brass would come in second, then aluminum. Of course, I talking custom manufactures. Only own one Lee and it's for my ROA.

Winelover

[ioon44]

I've only used Iron & Alum molds for the last 50 years.
They both work, I tend to gravitate towards aluminum molds and only 5 cav Accurate or NEI.

[Finster101]

I have all three. The different metals all have their own traits, but that can be said of individual molds as well. It seems each mold has it's sweet spot. I try and take notes of temp and cadence when I get one running really good and put a slip of paper with it so the next time I use it I get good boolits faster. I tend to cast a lot at one time or over a couple of days, so it might go a year or more between using some of them.

[Larry Gibson]

I have all three [currently have 87 moulds of single through six cavity] and only two of them are brass. I won't buy another brass mould as I've found aluminum or iron moulds to produce equal to or even better cast bullets without all the finickiness of the brass moulds.

[JonB_in_Glencoe]

What's the Best?
(I always love it when questions are asked this way, it always leads to an entertaining thread)

Myself, I prefer Aluminum molds for use with Ternary lead alloys.

While I have a few aluminum Lee RB molds, I also have Iron RCBS and Lyman RB molds ...I prefer Iron molds when casting with pure Lead.

[Cosmic_Charlie]

I have all three materials and they all can make nice boolits without trouble. I do like the cast iron molds the best as these seem to have less quirks. I spray my vast iron down with Birchwood Casey Sheath after use and clean them off with brake cleaner before casting again. Hate to have them rust.

[autogun]

Iron for me. I store them in those protective sheets that use to come with Smith and Wesson handguns. Never had a rust issue.

[Mal Paso]

Iron for me. I store them in those protective sheets that use to come with Smith and Wesson handguns. Never had a rust issue.

Excellent! A new excuse to buy more guns!

[Targa]

I won’t say one type is better than the other but my preference is aluminum.

[GhostHawk]

I have one lyman 2 cavity round ball mold for .45 caliber rifle.

Everything else is Lee and Aluminum. IMO the Lee 6 cavity's are the way to go.

[justindad]

Do iron molds perform better straight out of the box?
*
I have three aluminum 5-cavity molds, one 2-cavity brass, and a single cavity iron. The iron mold is the only one I have not had to deburr & otherwise fix.

[Winger Ed.]

Do iron molds perform better straight out of the box?

Actually, the few Lee molds I've had did better the first time I used them than the Iron molds.

Iron ones do OK right out of the box, but seem to improve over time where you could open
the handles and the boolits just fell out.

I figure the Iron molds are sort of like Grandma's beloved old cast Iron frying pan.
It also probably needed to be 'seasoned' when it was new.

[lightman]

I like iron but I have bought a few aluminum molds from Accurate lately.

[Velosa]

I prefer aluminum. Though I do have a bunch of brass as well. My brass molds tend to be a bit finicky sometimes.

[quilbilly]

I usually only do a few boolits (under a hundred) at a time after I finish other lead casting projects so I find aluminum to be more efficient for short periods. If doing a larger boolit making project, I usually prefer iron or brass.

[gwpercle]

I've never owned or cast with brass moulds ... when I got started it was Lyman and Herters Iron moulds ... then cheap Lee aluminunm moulds dominated what I bought .
It wasn't untill 2015 that I bought my first NOE alumninum mould ...
... that was an epiphany ... A Quality aluminum mould ... it was an amazing thing to cast boolits with and the boolits it dropped were beautiful .

Cast iron , Brass or Aluminum ... That's a tough one ... cast iron is rugged , brass is heavy and aluminum is light . The number of cavities plays a big part , I'm 72 and weight is now a factor , hand / arm strength is less and I can't sit and cast for hours at a time any more ... 1 1/2 or maybe two and I'm ready for a break and some Ibuprofen .
Taking those things into consideration ... I'm going with Aluminum , preferably a 4 cavity NOE in aluminum . I purchased a couple three cavity NOE aluminum moulds and they aren't much lighter than a 4 cavity NOE mould ... the three cavity are cool to pressure cast with a ladle and I like the fact they are unusual .
If I have to pick ... Aluminum !
Gary

[FISH4BUGS]

I use only H&G moulds. Once up to temp, they produce bullets like nothing else.
I use 4-6-8-10 cavity H&G's. As I get older, they get heavier. A mould guide is required on all of them.
I like them because of their lifetime of use won't even hardly break them in. :) My son and his kids will be using them.
I DO have ONE Lee 6 cavity 130gr 38 gc bullet. I have no idea where I got it but it casts wonderfully.
I load these in 357's and man do they shoot.
I load them with 295 powder and while the recoil is not bad, the muzzle flash is something to behold - especially in a 2" 357!

[Cast10]

Still a new guy as I see it…..My molds are Lee Aluminum. I use a Lee 20# pot, PID, and hot plate. I bring everything up to temp and am able to cast usable boolits from the start. I cast several hundred, up to 500 at one setting. 6 cavity molds.

[GONRA]

GONRA's Boolit Moulds are all Olde Lyman Cast Iron / Steel or LEE aluminum.
All verk Just Fine for my modest needs...

My olde Potter (?) Electric pot verks Just Great for "bottom pour" casting.

(Mostly "Range Lead" collector auto pistol boolits - nothing fancy.....)

[DocSavage]

Molds I have are either iron or aluminum. Had 1 mild made of brass but it was heavy and using it just wrecked my hands and wrists.

[Edward]

Iron 1st than aluminum and screw the brass (NEVER AGAIN)/Ed

[1hole]

I cast my first bullets in 1965 with two Lyman iron single and double cavity molds. The first alum block I got, in 1978, in .54 caliber Thompson-Center mold for my unbelievably accurate front loading rifle; to my surprise it worked as well as my iron molds, maybe better. Now I have a mixed few others and like them all. (I shoot, I don't collect reloading tools.)

The thought of buying iron molds because they can withstand more rough handling than alum is astonishing to me; I don't abuse ANY molds!

I find Lee's delightful and inexpensive 6 hole molds to be a delight to use. Like any other molds, how well the boolits may shoot mostly depends on the users guns, shooting, and reloading skills. I no longer enjoy sitting in front of a hot lead pot for hours and Lee's big molds can make a pile of good bullets quickly; I really like that!

[alamogunr]

I've got all three types but find that the boolits I favor come from the brass MP molds. I usually stick with solid boolits rather than HP because I don't hunt and don't like the extra work with the HP pins.

Recently I've been casting with some of my first molds which were Lyman, SAECO and RCBS one and two cavity. Just wanted to reacquaint myself with the boolits they produced. Except for the time to produce a good pile, they were the easiest to cast with, especially, the SAECO and RCBS. The Lyman molds were mostly acquired early in my casting experience and some had been "well used".

I just finished casting standard .45 auto round nose boolits to compare, with all three brands. Haven't shot any yet but hope to soon. Don't really expect to discover any real differences.

[Rich/WIS]

All mine now are aluminum, Lee 6 cav for handgun and NOE 5 cav for rifle. Have had steel molds, Lyman/Ideal and RCBS and they worked fine but were double cavity except for an old Ideal 4 cav 38 WC mold. Went with the 5-6 cav aluminum molds for higher production and less fatigue, an issue for me as a normal casting session is 800-1000 bullets.

[triggerhappynme]

Limited experience but so far I prefer brass. Mp hp mold after getting to temperature made me feel like I knew what I was doing.
Less luck with lee molds. They worked but not as nice or clean

[Bent Ramrod]

If I could wave a wand over my mould pile and change them all to a given metal, it would be brass.

The ones I have seem to need no obsessive cleaning, scrubbing, smoking, mould prepping, or other finagling, like some of the aluminum ones do. And they don’t seem to get cranky or balky in the middle of a casting session like some of the iron ones do, with the lead frosting, shrinking and rounding off bands until the temperature or casting rate or fluxing (or whatever it is) is tweaked or adjusted.

Most of the objections to the alleged weight of brass, as far as I can see, would go away if the blocks were made smaller. For some reason, (maybe to provide a “better” heat capacity?) a lot of brass blocks are larger than Lyman 2-cavity blocks, even though they’re for a 1-cavity mould. They cast well, but so do the small-block integral handled Yankee moulds I have, and the weight of those isn’t noticeably greater than the iron Ideal moulds.

But a good mould is a good mould, whatever it’s made out of.

[Eddie Southgate]

I have some of all three and they all do exactly what they are supposed to do so I see no advantage of one over the other. I actually have no idea of how many molds I have accumulated over the last 55 years but I can say that I am still short by a few. My next will be one for .348 for the Winchester model71 I just got last month. I also need molds for .32 S&W & L , 25-20 , and at least one for the .22 Hornet/ .218 Bee rifles.