Casting temp

[Tazman1602]

Just wondering how hot most of you run your melt. I’ve been casting a while and normally keep my melt at around 750° but it’s come to my attention lately that I *may* need to bump that up a little. Opinions welcomed.

Art

[Thumbcocker]

If you are getting good boolits of a consistent weight don't change anything.

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[Winger Ed.]

Do what works for you.

I run the temp up until It just starts to frost 'em. Then back it off a little.
I usually end up with my old Pro-Melt turned up to about 80% of the scale that's on the adjustment knob.

[Ed_Shot]

If you are getting good boolits of a consistent weight don't change anything.

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Agree....if it ain't broke don't fix it. For my 3-2-95 alloy in my PID controlled Lee 4-20 I've determined the sweet spot temp (thru trial and error) for the molds I use. My casting temp varies with mold material, number of cavities and boolit weight and the temp is marked on my mold storage containers. The results are totally consistent and repeatable. My temps are between 680F and 720F. Again, that's my alloy, my PID and my molds.

[Hanzy4200]

I'm curious also. I just upgraded to a Pro Melt 2, and it's the first time I can accurately control my temps. I found, bear in mind just one session and with 2 new molds, I increased to 800 from 750 and was getting better mold fill out. This is also using a very hard alloy I mixed for buckshot.

[lightman]

I cast at 725º. I control mold temperature with my casting speed.

[Rcmaveric]

I start at 750*F. Once mold is up to temp (about 3 cast from a preheated mold) and the bullets still dont fill out then i up the temp in say 75* to 100* increments till its good. I find myself personally casting around 850*F mostly but once or twice i needed togo 925*F (it was do to a zinc and cooper experiment). If i start getting over 900*F then i think about adding tin

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[almar]

Depends on the alloy. I usually run it at 700 or so with wheel weights and range scrap. But 1:20 with big bullets needs more like 850 and its stll a struggle. I am going to swich to laddles for those and leave the bottom pour for pistol stuff.

[RKJ]

I've ran my pots up to 800+ before and still wasn't getting good fill out. I got a $20.00 hotplate off Amazon and was off to the races. I run the pot now at 720-750 and am getting very good looking bullets, even HP's. That hotplate was a great investment.

[ioon44]

Using a PID I run around 700 to 710 deg F and pre heat the molds with a hot plate. The alloy I use most of the time runs around 11 BHN.

[JonB_in_Glencoe]

rule of thumb is...
Keep the pot temp at 100º above the liquidus temp of the alloy you are using.

COWW is liquidus around 550, so if the ambient temp allows, you could cast at 650.
Pure Lead liquidus is just over 621, so if the ambient temp allows, that could cast at 720.
If you are casting outside on a breezy 40º day, you'll likely need to run 100 degrees hotter.
What the mold likes, plays a part of the game, as well.

[Iwsbull]

I usually run around 800- 830 or so with a pid controlled pot, but I am casting hollow points most of the time and running 2 molds.

[Mal Paso]

690-710F with about 2 1/2 drops per minute for 125-270g boolits with hot plate preheat. 96/3/1 Alloy. Casting rate has a lot to do with pot temperature. Also the casting room is 70F, I don't freeze buns for boolits.

[jsizemore]

I'm with Mal Paso. Maybe a little slower on the casting rate because that's what the sprue cut tells me. I cast in the house with all the great AC and heating. Air cool everything.

[charlie b]

Took me quite a while but I finally found what works for me. Don't have a temp on the Lee pot but it is pointed right at the 8. The hot plate is something I'd never do without again and it is set on 4. I get good bullets right off the bat (I usually toss the first pour just for old times sake :) ).

I am usually pouring long skinny bullets (.30 cal 210gn) so the mold gets an interesting heat profile. I had a lot of problems with the nose being too hot or the nose was ok and the base would not fill out. So, I found a 'different' solution. When casting I let the sprue cool and then touch the bottom of the mold to a wet paper towel stack for a 3 count. This keeps the base hot enough to fill out well without being too hot in the nose. FWIW, this took hundreds of casts for me to figure out.

For other bullets I just cast as fast as the mold allows. If the sprue takes too long to cool I slow down a little. If it cools too fast I speed up. The cool time for me is a 5 or 6 count.

[Hossfly]

With a digital controller like a closed loop ddc with PID capability, I set it at 750’ after it brings pot up and starts to flow good, I set the next ingots to feed the pot on top of rim of the lee 20 pounder. That way temp doesn’t drop and stop flow out bottom pour spout.

I cast inside a room in my horse barn, no wind, and around 40-50’.

[country gent]

With the 20-1 I normally cast I run in the 725-750f range and adjust for ambient temp, bullet and other factors from there.

Many things affect the temp needed.
Alloy itself different alloys vary in melting temps to start with, a lead tin will be lower than one with lead tin antimony even the various percentages affect this
Mould material will want different temps also, aluminum seems to want a little higher Steel a little lower and brass maybe even a little lower as it holds heat better.

Bullets with more detail or finer features will take more heat for the best fill out. Hollow points some tumble lube or micro grooves will take more heat to maintain fill out.

Ambient temp cooler days winds will pull heat away faster Hot calm days not as much. A 20* ay will take a highrt pot temp than a 100* day

I cast from a gas fired 120lb pot it takes a lot to change vary temp once up to temp. I start at temp fr moulds and cast adjusting cadence to maintain mould if I can, a small adjustment to the flame takes a while to show up in the mass of the pot. On the few times I overshot temp I add a few ingots and start over. With my set up it is easier to sneak up on temp than back down to it.

Experiment with the temp and cadence find what works for you and your equipment. If bullets are frosting try slowing down a little or lowering temp here 10* can make a big difference. If fill out is varying speed up or add 5-10*.

[Shadow9mm]

So I'm still getting started but I have been getting good results so far. Using a lee pro 4 20lb furnace with no lead thermometer and lee molds. Usually casting around a 7 give or take a little. I start casting a touch on the hot side, around an 8, and drop the temp little by little until they go from frosty to shiny. I have a lead thermometer on order, but it got delayed with the weather. Once I get it and know what temperature I am actually posting at I will let you know. It will be nice to have a set temp to cast at.

[Tazman1602]

Thanks for all the input guys and I agree, it works for me so why change. That’s what I get for reading 40 year old books.

Art

[Winger Ed.]

That’s what I get for reading 40 year old books.

There's an argument for sticking with 40 year old books.

You might have been rocking along for all these years only to read a new book and find out you've been doing everything all wrong.:bigsmyl2:

[ShooterAZ]

There's an argument for sticking with 40 year old books.

You might have been rocking along for all these years only to read a new book and find out you've been doing everything all wrong.:bigsmyl2:

Well at least they aren't 140 year old books. They might have told you that they use a cast iron skillet to pour the boolits, and then turn around and cook their bacon and eggs in the same pan cause it's the only one they had. For me, 725 degrees is where I normally start, and move up or down depending on the mold and alloy used. It helps to keep notes of what works best for you regarding the mold and alloy. Because if you're like me...you won't remember.

[Winger Ed.]

Well at least they aren't 140 year old books. They might have told you that they use a cast iron skillet to pour the boolits, and then turn around and cook their bacon and eggs in the same pan cause it's the only on they had.

Oh yeah.
At Quantico, one part of the base was where Confederate forces camped and blockaded the Potomac for about a year and a half.
We'd dig around do metal detecting in their old camp sites.
There was lots and lots of Lead 'splashes' where they'd cast musket balls around their camp fire and toss the dross & dirt
out on the ground. I knew they only had their one pan from their mess kits to do it with.

[Tazman1602]

Well at least they aren't 140 year old books. They might have told you that they use a cast iron skillet to pour the boolits, and then turn around and cook their bacon and eggs in the same pan cause it's the only one they had. For me, 725 degrees is where I normally start, and move up or down depending on the mold and alloy used. It helps to keep notes of what works best for you regarding the mold and alloy. Because if you're like me...you won't remember.

Actually…the author, Paul Matthews did exactly that with a cast iron pot when he first started. I have gotten some VERY good tips from these books and intend to use some of them to improve my casting skills although I make very nice bullets now.

I don’t believe one can know everything about anything but if you choose to stop learning new things and think you do, well, enough said. I’ve gotten a couple of really nice molds in excess of 500 grains for an Uberti Sharps 45-70 and I can’t wait to try them out.

Keep the good info coming.

Art

[HATCH]

It all depends on YOU.

There are several variables to casting.
You can hand cast using a bottom pour or a ladle pour.
You can also machine cast using a Master Caster.
Your method doesn't really change the basic variables

Mixture of alloy
Temp of alloy
Timing

You want a consistent mixture. The way it flows, the way it melts, etc, needs to all be the same every time as it effects the other two variables.
You want a steady temp. It doesn't matter really if it is 650F, 750F, or higher. But you do want it to always stay a constant temp with very little fluxuations.
Now down to the last item. Timing. I saved it for last because it can compensate for the other two if you really know what your doing.
How long does the mold stay empty between fills, How long before you cut the sprue, How long before you dump the boolits, all of this is timing.
If your running a hot pot then you would keep the lead in the mold less time but you would have to wait longer to cut the sprue and you may have to let the mold cool down before pouring again.
If your running a cooler pot then you would keep the lead in the mold longer but would be able to cut the sprue sooner and have little or no cool down.

I am not a expert and I am sure someone will say I am full of it or wrong but it is always how I have done it.
I have a Automated Magma Master caster with a PID controller on the pot.
I can control every aspect of casting with the only variable being the alloy. I purchased several tons from a foundry so my alloy is pretty constant.

[Bigslug]

The happy place for me has been to set the PID around 775F, give or take a bit for the individual alloy and mold.