Mold Material

[Lights]

What is you favorite mold material and why, Aluminum, Brass or steel?

[USAFrox]

Since the only steel mold I have makes finned bullets, I'll have to say aluminum, because at least I get good bullets from them.

[Fishman]

Aluminum because it is light. :)

[wrench]

I have quite a few aluminum molds, a few iron, and one brass. The brass casts nicely, but it is a four cavity and it is h-e-a-v-y.
For a two cavity mold, iron or brass is fine, but for bigger molds, I really like the lightness of aluminum.

[jmort]

Aluminum - no rust. As Tom at Accurate says, "My favorite for my own casting is aluminum." Obviously, he could have any type of mold he wanted, aluminum, brass, or ductile iron.

[historicfirearms]

I like aluminum, especially the aluminum NOE uses. It's strong, light, and doesn't rust.

[bangerjim]

I have 18 Lee Al molds in 2 and 6 banger versions. And only ONE steel mold (pain the keister) brand unknown.

I will only use Al. They heat up fast and distribute that heat well. Smooth finish on castings. Just do not drop them or bang with a metal hammer! You will dent the edges and prevent closure. The you have to file down the divits to eliminate flash. NO RUST.

Aluminum is by far the less expensive and the best in my view.

bangerjim

[Red River Rick]

Why start another thread on this subject when there is already one going............

http://castboolits.gunloads.com/showthread.php?42570-Poll-Best-mould-material&highlight=Mould Material Poll

RRR

[Lights]

Why start another thread on this subject when there is already one going............

http://castboolits.gunloads.com/showthread.php?42570-Poll-Best-mould-material&highlight=Mould Material Poll

RRR

Well kick me for not searching for a thread that's last post was in January. Guess I will just stick to lurking and not asking or posting again.

[MtGun44]

All work well, no huge preference. Not rusting is a nice feature.

Bill

[Three44s]

I don't have a favorite as to usage but I certainly own a lot more aluminum molds than all the others put together.

When it comes to six bangers, they'd better be aluminum or I am going to weaken in a hurry!

But when it comes to beauty ...... then it's gotta be brass!

Best regards

Three 44s

[geargnasher]

My preference is that the thermal mass of the blocks is balanced to the size and shape of the boolits it makes. Nothing more frustrating than a small steel mould with two honkin' huge boolit cavities in it that constantly overheats, or a huge, heavy brass mould for .22s. I have a preference for brass moulds, but they all work.

Gear

[runfiverun]

I didn't know they even made molds from anything other than mehanite until a couple of years ago.
I have a few aluminum ones now and I do like them, but still have a fondness for steel 4 cavity molds.

[MtGun44]

I think only RCBS molds are mehanite, are you saying you only had RCBS molds? I
do think that mehanite is a superb and even superior material. I wish RCBS made
4 cav molds! (not a small group that has that wish!!)

Bill

[M-Tecs]

My preference in order of preference is brass, mehanite iron, 2024 aluminum, cast iron and last is the aluminum Lee uses. Some don’t like brass because it’s heavy.
Heavy is a relative term. I cast a lot with H&G 10 cavity molds so a 4 cavity brass mold is lite to me.:bigsmyl2:

[John Boy]

My molds are 50:50 aluminum & steel. Only 1 brass
So it's no preference

[rintinglen]

I like brass, iron and Aluminum--in that order. Brass is heavier, but tends to produce good boolits with very few rejects. I learned to cast with Lyman and RCBS molds, I know them and have learned to cast well with them. Aluminum molds tend to have more rejects, they lose heat more quickly and seem to have a more narrow "sweet spot." But they are light, cheap andmake lots of boolits quickly. As I get older, I find lighter is a very good thing: be it molds, guns, or recoil.

[jmort]

"I think only RCBS molds are mehanite"

And NEI

[TXGunNut]

I like whatever works. I have a couple of Lyman steel single-cav moulds that I wish were aluminum 6-cav's but they drop awesome boolits that work, can't ask for more than that. Steel takes a whole different technique than aluminum and not all aluminum moulds work the same. Don't have any brass moulds (yet!) but feel they are likely superior to other materials.

[MT Chambers]

I like Iron and Brass molds the best, but most designs come in aluminum, I think it's more of a matter of being much easier on machinist's tooling.

[btroj]

I am far more concerned with bullet design than I am mould material.

I like brass but my 4 cav brass mould is heavy enough to make me not want another one.

I really like Lee 6 cav moulds. No way I want one of those in iron or brass.

[Greg5278]

I have Molds made from Brass, 65-45-12 cast Iron, and Aluminum. They all have their purpose. I do like the Machining qualities of the 65-45-12, and the C360Brass. They give a good Finish if tyou ar making ur own blocks. The Downside with both is the weight. I like Aluminum for the fact is is light and does not rust, but it does easy suffer damage from a missaligned Pin or other problem easily. It also changes dimensions more than Brass or iron Molds when heating up. I have had several pins actually fall out on some Aluminum molds the first few times they were heated up. I even had used .001" oversized pins. I wouldn't make any more from Al, unless they were prototypes.

I have alway been tempted to make some molds from Aluminum Bronze. It is hard, and wear resistant and will not solder to the Bullet. The downside is cost, poor maching, and long stringy chips to contend with when boring the Cavity. I haven't given up, but it is a PITA to work with. Tapping holes can be a problem too, and it doens't like to give the best milled finish. If I were to go ahead, I would surface grind the Mold blocks once they were milled.

I also thought of using C17200 Beryllium Copper to make smaller Molds that had a problems with overheating. It is often used in Molds that are finicky or very complex in Nature.
The Downside is, it should never be ground Dry as the Dust is hazardous. It also costs more than even the Aluminum Bronze. It probably would last Forever given reasonable care.

I guess you could use Stainless Mold steel like 420 if you wanted to avoid corrosion, but I have no direct Experience with that. I don't know how well it would machine.
Greg

[geargnasher]

Contrary to popular belief, brass alloys generally lose heat three times faster than aluminum. The reason it appears to be opposite is that brass moulds typically are made from very large blocks, in part to reduce the natural tendency of brass to heat-warp, so there is more thermal mass in the mould than many of the aluminum designs. I've never warped an iron or aluminum mould of any brand, but have had issues with brass (my fault). Miha and Accurate have both taken measures to prevent warpage of their brass blocks unless they are really abused with heat.

Gear

[41 mag fan]

Contrary to popular belief, brass alloys generally lose heat three times faster than aluminum. The reason it appears to be opposite is that brass moulds typically are made from very large blocks, in part to reduce the natural tendency of brass to heat-warp, so there is more thermal mass in the mould than many of the aluminum designs. I've never warped an iron or aluminum mould of any brand, but have had issues with brass (my fault). Miha and Accurate have both taken measures to prevent warpage of their brass blocks unless they are really abused with heat.

Gear

Well I learned something else today. i never would of thought that brass would lose heat faster.
But i still like brass and aluminum. Brass first, then aluminum, but I'll take either or without batting an eye.

[Lights]

Greg5278,

420 machines pretty darn nice. I machine cavity and core block for plastic molds all the time.