Is it important to cast at a specific tempeature

[burbank.jung]

Currently, I heat up my pot where the Lee knob is just past halfway between off and high, drop my lead ingots in, and as soon as the lead is melted and my mold is heated, I start casting. Cast bullet keepers begin when my bullets don't have flaws. Maybe I should insert my thermometer to take a temperature reading and the lead happens to be the same temperature every time. I've read that you should turn your pot down untill you notice solidification and then turn the temperature up 100 degrees. What is your technique?

 

[waco]

Depending on what mold I'm using, I usually cast between 700-750

 

[Brad]

My pot is set at 700 and hasn’t been adjusted in years.
I worry far more about mould temp than pot temp.

 

[Glaciers]

My PID is set at 725* mold temperature as Brad indicates.

 

[Winelover]

Depends on your casting cadence. Whether or not you return your sprues to the pot.

Learned to cast without PID controlled furnaces. Never even used a thermometer.
Internetdidn't exist.

Learn by trial and error, combined with rote.

 

[Ian]

700-725⁰ pot temperature for anything having between 1 AND 5% antimony and .5 to 3% tin.

 

[CWLONGSHOT]

My pot is set at 700 and hasn’t been adjusted in years.
I worry far more about mould temp than pot temp.

Same here. 700 has been magic.

 

[Petrol & Powder]

I purchased a lead thermometer a few years ago. I think I have used it less than 5 times total, and I haven’t used it at all in at least two years (maybe three years).

The mold and bullets will tell you where you need to be in terms of temperature.

And that knob on a Lee 4-20 Drip-O-Matic is a rough estimate, at best.

As the pot empties and the mass in the pot decreases, the temperature goes up. When you add lead back to the pot, the temperature goes down. I use the graduations around that knob as an approximate starting point and adjust to meet to current conditions.

The temperature of the mold is more important and even that has a pretty big acceptable “window”. When the bases, noses and driving bands are crisp, it’s hot enough. When the bullets start looking “frosted” it is starting to get a little too warm. (but even then not out of the ballpark).

 

[todd]

the Coleman stove asks what is a temperature? lol

trail and error always.

 

[Petrol & Powder]

Years ago I started casting for Cap & Ball revolvers. Almost pure lead, round ball. I intentionally cast over a campfire to prove to myself that I could do it with primitive equipment.

I suspect hundreds of thousands of people made lead projectiles over the course of centuries without a clue of the specific lead temperature they were cast with. It worked just fine.

I progressed to a single burner camp stove (much easier) and then to an electric pot (way easier). I made great bullets without a thermometer.

I got a thermometer and saw absolutely NO need for the thing. Went back to casting without it and don’t miss it a bit. It sits on the shelf.

I cast about 200 bullets today, couldn’t begin to tell you what the exact temperature of the lead was. Nor do I care.

 

[Bret4207]

Got a thermometer, can't remember where it is. I start casting when the alloy is hot enough to run smoothly, get the mould hot by casting bullets and cast as fast as I can for as long as I can until the sprues start taking "too long" to solidify, which varies from mould to mould, then I slow a bit and keep casting. Worrying about perfect numbers is a waste of time in this game IME.

 

[Glaciers]

Yeah I used to do it that way until I got the equipment upgrade “Bug” and have been spoiled every since.

 

[Glaciers]

P&P -
Yeah I don’t need to think about the temperature either as my PID is pre set, so just flip the switch and put whatever molds I’m going to use on the hot plate and go get a cup of coffee. Nice.

 

[Petrol & Powder]

P&P -
Yeah I don’t need to think about the temperature either as my PID is pre set, so just flip the switch and put whatever molds I’m going to use on the hot plate and go get a cup of coffee. Nice.

I do the same thing. Plug it in, set it to "7" (whatever that equates to), go do something else.
The pot automatically and precisely sets the heat to an exact temperture ........I just don't know what that temperture is !!!!

 

[popper]

I set the PID to 725F, insert when alloy is fluid. Then wait (and stir some) for 15 min. Then pour. Typically bee wax on top that collects crud. Sometimes it will flame up.

 

[Brad]

I do the same thing. Plug it in, set it to "7" (whatever that equates to), go do something else.
The pot automatically and precisely sets the heat to an exact temperture ........I just don't know what that temperture is !!!!

But it works. Just shows that exact temp isn’t that critical.

 

[RicinYakima]

"7" relates to some point depending upon the temperature in the room. When I cast in my shop at 25 degrees, it is hotter than when I am casting at 65 degrees. FWIW

 

[burbank.jung]

How much of a temperature variation would I have to have to see a weight variation? I tend to toss any cast bullet with flaws back into my pot so after that my mold is above a certain temperature. I've never experience overheating my molds either but do you have a technique to maintain a stable mold temperature. Obviously setting a mold on the floor is not good. Would a hot plate on medium maintain a mold temperature do you think?

 

[fiver]

i know where my thermometer is.
it's over at my buddy's house along with one of my ideal molds.

i did use it to mark out some spots on my dial so i had a clue.
one big slash for bigger molds.
2 smaller slashes for 4 and 2 cavity molds.
i like to cast at the same pace no matter what i'm using so i marked things according to that more than an actual temp setting.

i also used the thermo to see how long it took for my pots to return to temp after dropping in various sizes of ingots at room temp etc.
at 60-F room temp a bigger '1lb'. ingot took over 5 minutes to get the lee 20lb'er back to where it was before i dropped the ingot in.

i done a long write up on the variations, temp drops, and recover time over at Boolits.
unfortunately i know for a fact it was wiped.

 

[RBHarter]

I think there is one here also .

Keeping moulds at temp is not a one size deal to be sure .

This all takes hands on doing.

A 5 cavity 37 gr 22 cal aluminum mould is nothing like running an 8 cavity 45 cal 200 gr iron mould .
2 cav moulds changing from iron to brass isn't bad but the jump from those to aluminum can be nerve wracking. Early on I had it all figured out I was casting beautiful 358-158s and 452-252 and 255s then I thought I was king of the world when I got the RCBS 45-200 and what a joy it was . Then I got me a 310-160 and a 323-175 ...... It took months to figure out how to get those hot enough to not get drips in the bullets .

Excerpt from something I read .
Ideal mould temperature resides at 350° , mostly for iron moulds .
Alloy has effect of 25° , honestly I can't remember if it wanted to be hotter softer or harder .....but it seemed at the time like it was backwards or inverse .

Another writer said ;
Use a clock to time each step for consistent pours .
Think of it as pouring heat rather than metal .

Then there was the Marine ;
You some lead .
Something to melt it in .
Something to get the lead hot enough to melt .
Something to put the lead in to form it .
Something to get the melted lead from the melting container to the form .
Try some stuff go shoot it .
If it doesn't work try some more stuff.

It's not rocket science, it's bullet science.

If it was easy anybody could do it .
It's not really all that hard .

I got to 9 push through sizers before I decided I should have just bought the stupid gas checks . On the other hand I can roll a decent paper patch and I have several really slick shiny barrels .