What is the advantage of a brass mold over aluminum?

[Jayhawkhuntclub]

I've never used brass or steel molds. What's the advantage, besides durability?
Thanks!

[Beagle333]

I just ran a poll on that. Here are the results.
http://castboolits.gunloads.com/show...Aluminum-thing

[country gent]

Brass holds heat much better and more evenly. Steel ( cast iron) also heats evenly and holds it better. From my years as a tool and die maker I found it easier to get the fine finishes easier with brass or cast iron. aluminum in certain grades could be a pain sometimes. I have been using my first brass mold for about 6 months now and really enjoy it casts great is very consistent and heats and stays hot. The big plus to an aluminum mold is the lighter wieght. Aluminum heats fast and cools fast making casting cadence more important.

[tomme boy]

Nothing! I like the Aluminum molds 10x's better. The problem with most alum molds is which type of alloy is used to make them. LEE is the worst of them all. They are very soft. Accurate and NOE are very nice and use a lot harder alloy.

[dragon813gt]

Nothing! I like the Aluminum molds 10x's better.

At least you said "I" and didn't make a blanket statement like some do. The biggest advantage as I see it is heat retention. Once the mold is up to temp it stays there. This allows me to cast a reduced rate. I'm not into speed casting. And w/ the increased weight of brass the slower speed is more to my liking.

You will get all types of opinions on which is better. I buy aluminum if it's the only option or if I'm trying out a new design and not sure if it will work. If it does, I buy a four cavity brass mold. I'm sure this decision is going to bite me in my older age due to the weight. But hopefully by then I will have a Master Caster, hopefully automated.

[John Boy]

Rapine & Accurate aluminums ... hardly able to see the parting lines and the base edges are not out of round & sharp edges

[Hardcast416taylor]

At this point of my life I tend to buy what I can afford as molds go! I would like to buy more brass and steel molds, but I also like to buy food and pay other bills!Robert

[TheCelt]

I have them all and like them all but MY preference is Brass. The material matches my casting cadence well and I find I get much smaller weight variances.

[shooter93]

And don't forget Brass looks way cool....lol.

[historicfirearms]

I like the aluminum molds better, especially the NOE ones. Lighter than brass and they don't hold heat as much, so I can cast faster and wont be tired out when I'm done. To each his own.

[longbow]

If I had to choose one I would go with iron. Second is brass.

Since you ask what the advantage of brass over aluminum is:

- brass is tougher than aluminum so harder to damage (think sprue plate rub/galling)
- as stated, brass holds heat better so even temperatures
- brass tends to machine extremely well while some aluminum alloys do not (NOE and other high quality aluminum moulds also have excellent machining qualities and finish)
- my opinion ~ brass is likely more suitable for Cramer style moulds where there is sliding action taking place. Aluminum tends to gall and bind if anything causes tightness.
- also as stated, "brass looks way cool"

Nothing wrong with good quality aluminum moulds though. Also, you could say that the low price of Lee moulds is a benefit in that you can get a less expensive mould or more moulds for the same money as brass, or a six cavity instead of a two cavity.

I have moulds in those three materials and others. I use them all... but if I had to choose one it would be iron.

Different strokes.

Longbow

[jmort]

Tom at Accurate prefers Aluminum for his personal molds. He will cut you what you want and his FAQs are informative. I have both and prefer aluminum. Here is his take:

"What are some of the properties of the different mold metals?
2024 Aluminum is very durable, light weight, and inexpensive. Its propensity to change temperature quickly is seen by some as a disadvantage, since molds produce their best bullets within a narrow temperature sweet spot.

Ductile Iron is the most durable of the commonly used mold metals. It is easier to maintain a more consistent temperature. It is lighter weight than brass and heavier than aluminum. Its biggest disadvantage is propensity to rust. Iron is rough on delicate boring tools, and thus it is the most expensive.

360 Brass is a bit heavier than iron, and costs less because of ease of machining. It maintains temperature very well, and cavities machine mirror bright. Some see its weight as a disadvantage.

Sprew plates and hardware are carbon steel.

My favorite for my own casting is aluminum."

http://www.accuratemolds.com/FAQ.php

[bangerjim]

I prefer Al molds:

light
cost-effective
readily available from several sources
heat up fast on the hotplate
give perfect boolits
do not rust or tarnish
6 cavity = lots of good boolits fast

I have a couple iron molds that are difficult to use for my purposes.

IMHO

bangerjim

[Bigslug]

My current thinking is I'll buy brass if it's an option for HP/HB molds, and I'll be getting Cramer style in those. I want HEAT in those pins! Otherwise, I've not seen any reason yet to use the yellow stuff over the silver stuff. I LIKE my NOE and Accurate aluminum solid cavities. There's nothing to casting with them!

[rintinglen]

Chief advantages of brass over aluminum? Heat retention and exercise! Two hours of casting H&G Clones with a 4 cav MP Brass and you start to understand how Popeye got that way, but the pile of excellent boolits dampens any criticism you might be inclined to make.

[osteodoc08]

It's kinda like having children. You love them all but they come with their own quirks.

But to answer your question: heat retention. That's about it. And they're purty. I can cast just as good a boolit with aluminum and steel. Aluminum can gall, but if you use an appropriate sprue plate lube (like Bullshop) it's a non issue. I can use 2-3 brass molds at a time and have a nice slow easy cadence and enjoy my time. With aluminum, my cadence is a bit faster. Sometimes I mix them up.

A quality mold is a quality mold regardless of material.

['74 sharps]

I've never used brass or steel molds. What's the advantage, besides durability?
Thanks!

Durability in a mold is a nice thing to have. Hardness of mold materials as follows:

Brass - 60 BHN

Aluminum - 95 BHN

Iron/steel - 220 BHN

[Screwbolts]

I have 3, Mihec 22 cal brass molds and 3, 22 cal Al molds, NOE, ACE and BRP. My money will be on Al from now on. That is my preference. and I counted 8 NOE boxs on the shelf today beside the 22 stuff. I ran 17 pounds of alloy threw a NOE 5 cav 246-75 FN today. no problem with heat.

Laus Deo,

Ken

[StrawHat]

Since heat retention has been mentioned a lot, is there a way to increase the aboility of an aluminum mold to hold heat? This appears to be a problem, especially with small caliber boolits. Perhaps one could machine a cavity into the mold and fix a brass or iron weight to add in heat retention?

[slide]

I have and use both. I don't think there is an advantage to one or the other. If you can buy both and see what suits you.