Idiosyncrasies of Iron, Brass & Aluminum for Newbies?

[X-man]

I was just discussing the ins & outs of casting with a potential new recruit to the ranks over the weekend and we had a pretty good discussion. I started casting with used RCBS, Lyman and Ideal moulds. In recent years I've been using custom NOE, Mihec, MM in both aluminum and brass.

I think we all probably have our personal likes/dislikes of each material, and have our own personal break-in procedures, maintenance regimes and casting techniques beyond standard/accepted practices. I thought it might be interesting for anyone who cares to, to share their thoughts, opinions, tips, tricks and preferences...And why, as both an academic exercise and as a one-stop "how-to" for newbies trying to figure out what type of mould will work best for them.

[country gent]

I perfer the cast iron malleable steel molds, Ive had several of the Lee aluminum molds and they were okay. I normally only buy Lees to test or if I want to modify to something else to try first. Ive never had a brass mold, but that may change. I like lyman, rcbs, and have recently bought a custom mold from Brooks. I dont have alot of molds right now but what I do have I use alot. I have used older molds from around the turn of the century friends own and all have thier own personalities.

[220swiftfn]

Iron molds here (old Lyman and RCBS).

One thing I will say about Aluminum molds is that they are great for beginning casters, they heat cycle quickly, making them a bit more "forgiving" to get good casts with, but they also tend to gall easily. Somewhere around here I have a Lee round ball mold that the sprue plate took a chunk of the cavity with it......



Dan

[dromia]

I have and use mould made from all three materials, my favourite has to be aluminium but purely from a weight perspective. I have arthritis in my neck shoulders and hands so I like to cast as many boolits in a sitting as possible as an hour at the pot is all I can manage now so like multiple cavity moulds hence my preference for aluminium. All materials make good boolits if the moulds are of a good quality.

For a beginner aluminium is probably the easiest to start with but it has to be from a mould that works, Lee's variable quality and the need for excessive fettling can put a new caster of unless they are lucky enough to get one that works. Lee's prices however are tempting to new starters. I always start new casters away on a god aluminium mould from NOE, Accurate or any other respectable mould maker. Once they have gained experience on the aluminium then they are equipped to try the others. How ever if iron or brass are the only options then go for it as like many here I learned to cast on iron moulds with no problem.

[DRNurse1]

I started with iron 4 cavity moulds and that probably clouds my decision process: I compare any mould I use to that H&G #68 that had already cast a million (really) boolits. My FiL was monitoring my work by my side initially, then after MANY sessions, he let me go it alone and just checked the results. That mentoring is probably the single greatest reason for my casting success.

Lately, I use a number of iron moulds from different manufacturers, including H&G 'knock offs' with good success. I have used only one brass mould and no aluminum molds however I like the positive entries regarding both of these mould materials. I have recommended aluminum and brass molds to other casters with the preface that they should strive for the best available mold at their price point. Since joining here, I discovered an additional benefit to the iron molds: resale value. But I will continue to recommend aluminum and brass if iron is not a financially manageable choice.

I bought one of Mihec's brass moulds (fell into a group buy near the production date when someone else dropped out--THANK YOU, Someone Else). Initially, a bit of a learning curve but I managed to produce useable boolits fairly quickly thanks in great part to my experience with iron molds. While there is no great weight advantage in this particular mold, the design allows FP, HP, and HP Penta booolits from the same mould. I have not found this ability in a reasonably priced iron mould. Mihec's work is top quality and he has a creative and useful solution to multitasking your mold.

Speaking of learning curves, some goof off tinned my brass mould (...okay I was not paying close enough attention when I was trying to preheat that mould on my furnace....). Thanks to folks who paid attention or had already blazed that trail, I have returned the mold to normally functioning condition. Mihec also returned my e-mail for direction in recovering that mold without damaging it. I have heard about the customer service from some other populist mold makers (not good, though no personal experience) and custom mold makers (much better, but they are making molds not fix your mistakes).

In the mean time, I learned a bit about 'beagling' ( I managed to make useable 0.358 boolits from my 0.356 mold and my S&W 14 likes them) and a lot about patience and preheating on a separate hot plate dedicated to casting.

[DRNurse1]

Duplicate oops.

[hermans]

I have just finished a 2 hour casting session with brass 4 cavity 200gr H&G#68 clone from Mihec. I made 850 perfect slightly frosted boolits in this period, and was just saying to myself that casting does not come any better that this!
I do have another 4 cavity brass mold from Tom at Accurate, also a flawless mold. I also do have many RCBS molds, nothing wrong with them also, but once you have hit the sweet spot with a brass mold......there is just no looking back.
The only downside of the brass molds is the weight, but I am lucky to still be able to cast for 2 hours on the trot before tiring.
For me, brass is king!

[dg31872]

Cut may casting teeth with RCBS, so probably influences my choices some, but for me, if RCBS made 4 cav., I would be in hog heaven.

[btroj]

Brass is heaviest, iron in the middle, aluminum is lightest.

All have a different specific heat- how well they stay hot. This means they all need to be run at a slightly different tempo. Cavity size also affects the required tempo. Not a huge deal, just realize that 2 moulds that are identical except for block material can have very different preferences in how they prefer to be run.

I like brass. Makes for very smooth cavities, doesn't rust. It is darn heavy though. A 4 cav brass mould is tiring for me.

For more than 4 cav aluminum is the way to go. Brass or iron get so heavy that the mould just isn't manageable.

Aluminum moulds are far more prone to galling on top of mould from sprue plate. Keeping this lubed makes a huge difference. Aluminum moulds are made from a softer material so they require a bit more care in operation but if you are rough enough to damage an aluminum mould then you need to look at your casting routine and make some changes.

I shop far less based on block material than I do bullet design.

I prefer brass for 2 cav moulds but use far more 6 cav aluminum moulds because they fill my needs better.

In the end, they all work. They all produce good bullets. They all require some care in operation and some TLC.

[RED333]

I like the iron best, easy to heat, just the right weight, oil after EVERY use and they last a long time.
Brass is heavy, but as said before, ya get the HP option with no HP as well.
ALU is good for 6 cavity to make a lot of boolits fast, just have to watch the scraping of the
top.

[FishingFool]

First mold was a two cavity 405 gr 45-70 aluminum mold. Second was a pair of Lyman 9mm 147 gr iron molds. I liked how iron casts so much I ordered another iron 45-70 mold.

[paul h]

I've cast all mold materials and here are my thoughts.

If money is not an object and I can find a bullet design I like than an H&G or Ballisticast H&G style hand casting mold is the best mold money can buy. H&G set out to build the highest quality molds and they achieved that. I say this having cast molds from every other maker. The H&G is a joy to use and cast quality bullets cast after cast. Cast iron produces and excellent cavity and holds a consistent temperature.

Aluminum is my second favorite and generally my first choice as it's the least expensive. I don't abuse my molds so haven't had any issues with it being a softer metal. I have bought some used molds that were damaged so I prefer to buy all my aluminum molds new. They heat up quickly and so long as the blocks are of a reasonable size hold a consistent heat. The lee 2 cavity molds definitely need a consistent cadence due to their small mass, but for the money they are excellent molds. The 6 hole lees are outstanding for producing mounds of bullets. For customs Mountain Mold's are excellent and I really like the online design tool.

Brass has been the most fickle material to me. My MP 360640 is astounding and an absolute joy to cast, but in the larger diameters and heavier bullets i.e. 475's in 500's in 400-500 gr I find brass has a narrow temperature range of too cold and too hot which yields problems. Mihecs are amazing so I'll tolerate the brass, but the MM and Applegate brass molds I've cast leave me somewhat down on brass in terms of castability.

[bangerjim]

Al molds will last for years if treated properly. Al is soft and will gaul/ding, so you have to treat them as such. I prefer the lighter Al molds to the heavier brass and iron ones. Have a few, but use Al mostly. Not due to cost, but to performance I have seen.

You will be happy with any of them.......................because the cast boolits!!!!!!!!!!! :drinks:

bangerjim

[**oneshot**]

I have a mix of NOE(aluminum), Accurate Molds(brass), and Saeco(steel). I cast all my molds with 725-750temp. This gives me the best fill out. The biggest difference is the time between casts and also the method of casting. Some molds like to just be poured til they fill others like a little over pour, and others yet like to have the ladle pressed into the sprue and turned over. I have a cheat sheet above my casting bench for each mold.
Each mold will let you know when you have it right.
New molds go through a cleaning with dishsoap and 3-4 cycles through a 380degree oven and cooled to the touch between heatings.
All molds get set on a hotplate (I have 2 saw blades on top of hotplate to prevent direct contact with the element) to preheat while I get the pot ready. Once the melt is up to temp and fluxed I start casting.
With the steel and brass, Once I start casting the hotplate is no longer used unless I take a break. With the aluminum ones they go on the hot plate while waiting for the sprue to cool.
Always use sprue plate lube on sprue plate and alignment pins reguardless of metal. Repeat application after I take a break.
I never clean a mold unless it starts acting up. A hot mold is easier to clean than a cold one.
I store all my molds in old sweatshirt sleeves that I have sprayed with gunoil and dried. I tie off the cuff end like a gunsock. They are then put in plastic bins with lids and I throw a few Silicone packs or anti rust chips in with the sleeves.

One other note for the newbies--- An over tightened sprue plate will give you alot of headaches and never seem to be the obvious problem. Always adjust your sprue when the mold is hot.