some like it cold

[Kevin Stenberg]

I didn't want to step on Elric's post. But in 1 case I like it cool.
Most of the time my pot temperature runs 700 to 710. I tried casting at a lower temp. yesterday and my rejects drastically diminished. this experience is only with 1 mold ( I just tried it yesterday) I used a NOE .358 135gr 5 cavity mold. I set the temp to 695 deg. and I used a 6 count between bullet dump and refill and a 3 count for sprue cut. But my weight variation was still about 4 grains lightest to heaviest. And my reject weight variation out of my 2 grain weight target was about 25%.
On a whim I turned the melt temp. down to 685 deg. And kept my casting tempo the same. I was pleasantly surprised that my weight variation dropped dramatically. My new weight target became 1 grain variation. My reject rate went from 25% down to 10%. I only had 10 over weight and 15 under weight bullets. Almost all of the under weight's were caused by incomplete fill outs on the bases caused by my casting experiments as I went
I know this is only 1 case with 1 mold. So it is not a rule just an observation

 

[quicksylver]

I have at least a dozen molds and find that with a 90/5/5/ alloy all will cast beautifully with the pot temp set for 680 deg. ( I use a thermostat)...
When using COWW + 2% I will raise the temp to 700 degrees..

Mold temps run 350 -370 deg ( again with thermo)

 

[358156 hp]

Man! I can't get decent results at 700 degrees with my iron moulds, especially the 4 cavs. 720 is usually the minimum temp for most of these moulds, and the 4 cavs require a bit more than that. I especially run into problems with bullet designs like 358156 & 452460 that have pretty narrow bands. I do add tin as required, but some of them just require a bit more heat. Contrast this with my original H&G 503 that required much lower temps than any of my other moulds. Each mould has it's own personality, I reckon.

 

[Brad]

Yes, each mould is unique. Block material makes a difference as does block size and bullet design and number of cavities.
I have an NOE 4 cav 314640 I damn near have to race with and a Lee go up buy 6 cav for a 460420 plain base I need to crawl with.
In the end it comes down to maintaining mould temp in the right spot via heat dumped into the cavities.

I have started running at 700 for most casting. I don't seem to spend as much time waiting on moulds to cool a bit. I used to go with 725 but decided to give 700 a shot and I'm glad I did.

 

[Ian]

The Lee commercial blocks do best with bullets in the 125-200-grain range. Lighter and you have to frantic-cast and run hotter alloy, heavier and you might as well run two of them at a time.

I usually let the alloy determine casting temperature. Antimony at 2-3% and low tin, have to run the alloy at at least 725 to keep it liquid enough to fill well. Straight WW at 700 or 715 most of the time, and if I add 2% tin for a 3-3-94 alloy I can usually go clear down to 650, which helps with the heavier bullets unless I need them to cast larger, in which case I'm back to 725 for maximum diameter.

 

[JWFilips]

700 to 725 depending on my alloy & mould but most times I'm in the middle of those two temps.
Even though I have been casting for a number of years I'm still learning what temperature does to bullet size.
I do like a light frost however a bit too much & I see my drive bands are rounded

 

[RicinYakima]

I cast linotype for match bullets, about 675, or other alloys a minimum of 100 of liquidous temp. I have an Accurate aluminum mould now, and had to add 15 degrees. FWIW, Ric

 

[Creeker]

When I first opened Dry Creek it was my goal to sell nothing with a "frost" mark so I ran lower temperatures with 92-6-2. I could cast well filled bullets that shined like chrome. It took a while to learn each mould or combination of moulds in order to do this. Once I stopped sending bullets to the rag authors & sold off my webpage I went to wheelweights & range alloy, higher temperatures & lite frosting all over. And these days that's how I cast for myself.

 

[Hawk]

I like a little frost on my bullets. Those are usually the most consistent with the fewest rejects.

 

[KHornet]

I also prefer a little frost, and agree with consistency. You really have to cast fast and consistent when doing small 224's.