Brass vs Iron or Aluminum Molds

[Alstep]

Want to order a new mold. Never cast with a brass mold so thought maybe I'd try one. Any advantages/disadvantages of brass vs iron & aluminum? Will the lead alloy "solder" onto a brass mold?
Your thoughts please.

[upnorthwis]

I like aluminum for the light weight and easier to get up to temp. From what I've heard of brass, people get them because they look nice.

[DAFzipper]

If casting larger quantities I prefer aluminum due to weight. I have several brass moulds also. Mostly hollow point designs. M&P only does hollow point moulds in brass. After a couple of hours casting with a brass mould I remember why I prefer aluminum. With care durability isn't an issue with aluminum.

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[country gent]

I have brass and iron moulds mostly ( only a couple of aluminum moulds from Lee). Heres what I have found and learned. All will cast very good bullets, Its more the makers craftsmanship than the material. All have their pros and cons.

Brass:
Heavier for given size of blocks weight wise. Heats evenly and holds heat longer. Machines easily and has a very nice smooth finish. May take a session or 2 to break in and cast their best. Dosnt rust.

Steel / Iron:
middle of the 2 concerning weight. Heats and holds temp well. A slightly coarser surface than brass or aluminum. very durable and long lasting. It will rust if not cared for. A good all around material and very useable.

Aluminum:
Lightest of the 3 materials this can make a big difference in long casting sessions. Softest of the 3 materials. Heats and cools the quickest, meaning cadence is more important with these moulds. Doesn't rust. Do to softness more care is required handling. again it machines easily and has a very fine polished finish.

I have brass moulds from Old west moulds, steel from Lyman, RCBS, BACO, Brooks, and aluminum from Lee. All are for BPCR bullets in various calibers from 38-45. All are heavy for caliber.

Casting with the brass moulds I can take a break and flux the pot pick the same 2 moulds up and go back to casting with out any concerns. ( The draw back to this is when done it takes longer to clean up because the moulds take so long to cool down. They cast great consistent billets and will run all day long. My usual 4 hour session will result in a few hundred bullets all with in .5 grns
The steel moulds take a little faster cadence to keep hot but cast great bullets and again consistency is very good.
The aluminum moulds cast good bullets and I get good weights but they just seem a little fussier at times. Cadence is noticeably quicker do to the faster cooling but then so is clean up at the end of the session.

I cast from big gas fired pot with a ladle. I normally run 2 moulds at a time. I over pour the sprues. I start with the brass moulds first casting what I need then the steel/iron moulds and last the aluminum.

[robg]

Use both iron and ally ,ally is easier on my wrists both cast good boolits.

[gwpercle]

Use both iron and ally ,ally is easier on my wrists both cast good boolits.

Ally is the new term for aluminum ?

I bought a aluminum 4 cavity NOE , my first 4 cavity.... It is much heavier than I expected , I don't think I could cast much with a 4 cavity brass mould .
I ladle cast and the wrist and back gives out after one 20 pound pot of metal . I started casting using both left and right hands and that seems to spread the load out , fill with the mould in left hand, open the mould with it in right hand , try it if you're having trouble with the heavy weights .
Gary

[WHITETAIL]

I have some of each.
The molds I have are mostly
2 cav. and singles.
To me, they seem to work good.
Yes they all have their own personality.
But to me making boolits is not a chore.
The ones that are NOE are great.
The ones I got that are RCBS, Lyman,
Ideal, Saeco, and Lee. Needed a little
T L C to come out the way I needed.
Get the best you can afford and have fun!!!!!

[Bazoo]

I have both iron and aluminum, I prefer the iron. It's easier for me to keep it at correct temperature. The advantage of Lee moulds is not there material but there low cost and widespread proliferation.

[Lloyd Smale]

steel brass aluminum in that order. Aluminum are nice for there light weight but just don't hold up well.

[Harry O]

I have some of all three. All are good for some things and not so good for others. The aluminum are much easier to cast with during long sessions because of the light weight. Small aluminum moulds (like Lee) with large bullets overheat easily. Works great with smaller bullets. I have three brass moulds. They are heavy and very tiring with long sessions. They heat up quickly and maintain their heat well. They do not "solder". Steel or iron are fairly heavy and heat up slowly. It is often hard to reach required temperatures with small bullets in large moulds. Big bullets work OK.

[jeepyj]

I have brass and iron moulds mostly ( only a couple of aluminum moulds from Lee). Heres what I have found and learned. All will cast very good bullets, Its more the makers craftsmanship than the material. All have their pros and cons.

Brass:
Heavier for given size of blocks weight wise. Heats evenly and holds heat longer. Machines easily and has a very nice smooth finish. May take a session or 2 to break in and cast their best. Dosnt rust.

Steel / Iron:
middle of the 2 concerning weight. Heats and holds temp well. A slightly coarser surface than brass or aluminum. very durable and long lasting. It will rust if not cared for. A good all around material and very useable.

Aluminum:
Lightest of the 3 materials this can make a big difference in long casting sessions. Softest of the 3 materials. Heats and cools the quickest, meaning cadence is more important with these moulds. Doesn't rust. Do to softness more care is required handling. again it machines easily and has a very fine polished finish.

I have brass moulds from Old west moulds, steel from Lyman, RCBS, BACO, Brooks, and aluminum from Lee. All are for BPCR bullets in various calibers from 38-45. All are heavy for caliber.

Casting with the brass moulds I can take a break and flux the pot pick the same 2 moulds up and go back to casting with out any concerns. ( The draw back to this is when done it takes longer to clean up because the moulds take so long to cool down. They cast great consistent billets and will run all day long. My usual 4 hour session will result in a few hundred bullets all with in .5 grns
The steel moulds take a little faster cadence to keep hot but cast great bullets and again consistency is very good.
The aluminum moulds cast good bullets and I get good weights but they just seem a little fussier at times. Cadence is noticeably quicker do to the faster cooling but then so is clean up at the end of the session.

I cast from big gas fired pot with a ladle. I normally run 2 moulds at a time. I over pour the sprues. I start with the brass moulds first casting what I need then the steel/iron moulds and last the aluminum.

Excellent write-up and in my opinion spot on.

[mold maker]

Starting with no experience, it will take some experimenting and lots of reading to become proficient with each type and size. I've used molds of all metals and number of cavities. The major difference is weight and ability to take abuse. Each mold type and size is a challenge of its own. Keeping a consistently hot mold is imperative.
After learning each molds particulars, you'll find they are like children. Each will produce good quality boolits and a long life of service, depending on the TLC you give it.
Your question about soldering of alloy to a brass mold is valid. Most brass mold mfg offer suggestions about heat treating the fresh brass to avoid the problem. Basically the brass needs a coating of oxide on its surface. This is accomplished after cleaning of oils, by heating the open mold several times before introducing alloys containing tin. Oxidized brass takes on a darker color and acts as a mold release.
You've come to the right place to get the skinny on casting. Asking questions is important. Many expensive and annoying mistakes can be avoided by using the experience of others whose path you follow.

[LenH]

No experience with a brass mold, but each of the 6 aluminum NOE molds are unique critters and require different casting techniques. I have to cast faster with some than others
due to bullet size and diameter. Some like the melt a bit hotter than others say 730° and others around 700° or a bit less. I can usually cast longer with these molds as they are of
lighter material. I have an 8 cavity H&G iron mold that I usually limit my casting sessions to about 30 minutes or less due to draining the pot.

[country gent]

My bigger 2 cavity moulds (45 cal 550 grn 40 cal 425 grn ) really empty a pot quick when casting even the 20 lb pots go quick. I ladle cast from a gas fired pot that holds 125lbs of 20-1. even with it you can see the pot level dropping when running 2 moulds at a quick cadence. There's only 12 of those 550s in a lb of lead LOL. SO the normal sized pots go quick. The bigger pot is a plus for a couple reasons.1) it simply lasts longer in a session, 2) Temp swings from high to low are much smaller di to the added mass. 3) bullets stay more consistent thru the sessions.

My casting pot is big enough that I usually invite 1-2 friends over to cast with me. This is a plus as I have help there with my mobility issues we talk and enjoy each others company, Of something does happen there's someone there to help or call for help. Its also Handy when working with a new caster starting him or her out. And If Im really short on bullets my son and his friend running my moulds effectively triples production for me. LOL

[georgerkahn]

Having roughly fifty years of casting, with my collection in three digits, I have moulds in all three metals. I am 100% in concert with Lloyd Smale's order of preference. I will add, however, that the "weight" issue is pretty much of your choosing. To wit, I have, say, iron (e.g., Ideal, Lyman...) moulds which are single cavity, two cavity, and four cavity. Hensley and Gibbs? I have a few 8- and 10-cavity moulds of this manufacture. Most of my brass moulds are two and four cavity, while those in aluminum are four or less cavities.
Not rocket science, if weight is of importance, just get moulds with fewer cavities. Yes, your production rate is proportional to the number in the mould you're using, but -- primarily due to the 70 candles on my last birthday cake, I have had, let us say, less fun using all mould with greater than three cavity size, based upon their respective weights. My production rate actually has not significantly diminished! Regardless, though, in terms of a "rewarding casting session", it seems my best results come from my iron, then the brass, and lastly the aluminum.
I have brass moulds in the 100 vicinity, and have yet to have any "solder"-type affects. Bion, I have purchased (used) iron moulds which came to me with lead smears all over them -- but, again, I've never experienced that in my brass mould casting.
BEST!
geo

[rintinglen]

In 1966, at the ripe old age of 12, rising 13, I cast my first boolits. Like George, I have scores of molds and I dare say I am well into casting my second ton of boolits, if i am not into my third. I like Iron two cavities and under, Brass hollow point, and aluminum 6 cavities and up. Brass molds, once to temperature, make good boolits more consistently with fewer rejects. Iron molds are almost as good as brass, but weigh less, and don't hold to temperature quite as well. Aluminum molds heat up and cool down rapidly, resulting in a larger number of rejects. Cadence is more important with Aluminum molds than those made of Iron or brass.
Aluminum is also less durable, though it also fair to say it doesn't corrode as quickly as Iron.
At the end of the day, though, I own and use all molds of all 3 metals and just look at what the mold is showing me. I adapt my fill rate and alloy stream flow to get the best results.

[Petrol & Powder]

Country Gent's post #4 is well written and spot on. Thank You Sir.


I have a few aluminum molds but I far prefer iron.
Ferrous metals will rust if not cared for. I'm pretty old school when it comes to tools and consider the need to oil/grease iron & steel tools as "just part of the job". I really don't mind the extra time it takes to properly store an iron mold or to degrease one when I take it out of storage.

I have some hand me down tools that my father got from his father. If you buy good quality tools and take care of them they will take care of you.

I don't think aluminum molds are bad and they have their place but to me a mold is a once in a lifetime purchase. Unless I treat it poorly, an iron mold will likely out live me.

Brass is appealing because it will not rust and they hold heat well but the material is a little bit softer than iron. I can get past the initial high cost for brass because I'm going to keep it a long time but greater strength (hardness) of iron wins out in my book.

I will also say that the iron used in RCBS and SAECO molds is very high quality. I wish RCBS made 4 cavity molds. If I want a 4 cavity mold the SAECO is my fall back.

[robg]

Over here we say al- you -mini-um therefore ally for short .don't work for aloominum sorry.

[44Blam]

I prefer Brass...

[44Blam]

Over here we say al- you -mini-um therefore ally for short .don't work for aloominum sorry.

I work with a bunch of South Africans, they say the same - but they live in America, so it is Aloominum here.