What temp??

[Vance in Ak]

I've never had a casting thermometer before but intend to start playing with the new one from RCBS that I have.
Jusr curious, when casting large boolits (400gr) from WW alloy what temp do you guys shot for?

[243winxb]

780* for alloy. Mold temp 450*

[That'll Do]

The largest boolits I cast are 250gr ones for my 44 Special, and I find that 700F works fine. I don't have a way to measure my mold temperature, but I do preheat them on a portable electric burner set to "medium", whatever that may be.

I cast with WW w/ tin added.

[RobS]

Alot depends on what your mold is made of.............iron, aluminum, brass, etc. It also depends on your casting technique and if you are ladle pouring or casting from a bottom pour.

A bit more info can help us give you a better temperature range for your intended purpose.

[LAH]

This changes from mould type, alloy & casting method. These below from another thread were cast using a bottom pour pot & three 4 cavity moulds at 800 degrees.

http://i66.photobucket.com/albums/h244/Creekerpics/Picture515.jpg

http://i66.photobucket.com/albums/h244/Creekerpics/Picture516.jpg

[Humbo]

650-700 degrees works for me.
http://home.online.no/~kjel-phu/bilder/IMG_4232.JPG

[LAH]

Which mould is that Humbo?...........Creeker

[excavman]

Nice castings LAH and Humbo, looks like 429421. Like many other things we do in the shooting sport use moderation and play it by ear, too hot gets frosty, too cold won't pour. The temperature depends on what you're casting at the time and the alloy and how fast you are working.

Larry

[MtGun44]

No, I think that is the 454424, Elmer's .45 Colt boolit.

Bill

[RobS]

Yep I think Humbo's is the 454424 GB designed by one of our forum members

[Humbo]

It's the one and only RCBS 45-270 SAA. Alloys was between 650 and 700 degrees, I was casting fast and cooling mold just a little on a wet sponge after every 3 pours.

[RobS]

I have cast the 45-270-SAA and it's a nice bullet and I had pretty good results from it. I know have moved to LFN bullet design and have had more versitility. Good cast pics Creeker and Humbo.

[Wayne Smith]

To get back to the original question, I'm ladle casting and the big 45-70 and 500 S&W molds do best between about 780-820. I don't have near the temp control I'd like and mine often fluctuates about that much anyway.

[RobS]

Yes back to the question..............as a general here...............iron molds will cast with a bit cooler alloy temp as iron holds heat better than aluminum. That is why Humbo was casting at 650 to 700 degrees with an RCBS 45-270-SAA Iron mold. I bottom pour cast 300 + grain 45 cal bullets at 800 ish degrees with aluminum molds. We don't know what Vance in AK is working with exactly except big bullets (400 grains) and WW alloy. When we hear more from Vance in AK then we can all chime in on what may help him.

[Humbo]

That is true, iron molds are more forgiving as far as temperature is concerned. When casting with aluminum molds I usually ramp it up 50 to 100 degrees compared to iron molds, but I still try to keep the temp as low as possible. I don't like frosted boolits, I get smaller variations in weight when they're all shiny.

[jimmeyjack]

I haven't been casting long, but I noticed the things Humbo says is right on with what I have found.

[LAH]

It's the one and only RCBS 45-270 SAA. Alloys was between 650 and 700 degrees, I was casting fast and cooling mold just a little on a wet sponge after every 3 pours.

Been a while since I cast with mine, guess I forgot how good they looked.

[KYCaster]

I thought I cast some pretty nice boolits till I saw these pix, now I'm embarrassed.

Great looking boolits, guys.

Jerry

[Vance in Ak]

Thanks for the input guys.
Pretty wide range of temps here. 650-820.
My mold is a LEE double cavity.

[Marlin Junky]

760F is a good place to start if you are using an RCBS ladle and a single DC Al mold.

MJ

[armyrat1970]

Thanks for the input guys.
Pretty wide range of temps here. 650-820.
My mold is a LEE double cavity.

Hi Vance. I also use Lee molds. My 357, 45 and 30carbine are double cavity. My 8mms are single cavity. I have found, that contray to popular belief, the Lee aluminum molds take a little while to heat up evenly. And cool rather quickly. I now use a hot plate, at the highest setting, to heat the mold and run my temps between 780 and 800.
I have bad eyes and start to get a little crosseyed after dropping 30 to 50 boolits from my Lee 20 pounder. I then take a break. Throw my sprues back into the pot. Set my mold on the hot plate. Check my boolits and throw the rejects back into the pot. Smoke a cig and drink a beer. Check to make sure my temps are back up to 780 or 800 with my RCBS thermometer. Than start casting again, until I start getting a little crosseyed again. Then I do the process over.
I have tried different alloy temps with the Lee molds and it doesn't seem to keep the mold hot if lower than 780 to 800. At 600 or 650 I can drop 10 or so boolits, with the first ones coming out a little frosted, but after the 10 or so, they start getting wrinkles because the mold is cooling down.
Now with your molds dropping 400gr boolits, you may find the mold may heat up a little quicker. Because there is less meat around the cavity. But they may also cool down quicker. Because there is a little less meat around the cavity to hold the heat.
You may need to run you alloy temps a little higher. 800 to 820. Gives you a reason to use that RCBS thermometer.
I would start with a really hot mold and the alloy temps being around 780. Drop a couple of boolits and check them. Drop 20 more and check the last two. If all is right, roll with it. If you're starting to get some wrinkles, however slight, crank your temps up a little. On your alloy.

[Vance in Ak]

760F is a good place to start if you are using an RCBS ladle and a single DC Al mold.

MJ


Lee production pot

[Changeling]

It's the one and only RCBS 45-270 SAA. Alloys was between 650 and 700 degrees, I was casting fast and cooling mold just a little on a wet sponge after every 3 pours.

Humbo if you don't mind my asking, what alloy were you using, they are some of the best castings I have ever see on this forum.

[HORNET]

Vance, the real starting point is the melting temperature of your alloy. I can cast quite well with 50/50 WW/Lino at a temperature that barely gets pure lead melted (with some molds). Bass Ackwards claimed a couple of years ago that you should start 100 degrees above the melting temp for iron molds and 200 degrees above it for aluminum molds. That seems to work as a good starting point for me but may need modified depending on the amount of fine detail in the cavities, the number of cavities, and several other factors. YMMV

[Humbo]

Thanks for the input on my boolits guys.
@Changeling: Thank you. This thread was initially about ww alloy, the boolits in the picture were cast with an alloy with 2 parts ww and 1 part lino. I added the lino just to bring the hardness up a little, I get similar results with straight ww alloy when I do my part.

I'm pretty anal about my casting, but it pays off. I prep the molds properly, then I bring them up in temperature to the point where I get slightly frosted boolits. Then I figure out how often I have too cool the molds just to avoid any frosting. It's easier to get the mold a little too hot and then bring it down to temperature, than the other way around. It takes me a couple of tries, but after that, I can cast hundreds and even thousands of boolits, with no rejects. The picture is taken of a box with about 20 pounds of boolits in it, and I didn't take out one single reject after I got going. And I cast fast, as fast as I can as long as I keep the cooling consistent. I also keep the sprue puddle as consistent as I possibly can.

For example, with an alloy temperature of 650-700 degrees, casting with the RCBS 45-270SAA I cool the mold about one second on a moist sponge after every 3 pours. It's not always needed, but it keeps the mold temperature consistent. I keep the sprue plate just cool enough that I don't get any tearing in the center of the base where the sprue plate holes are when cutting the sprue. This is pretty far from the point where you start to get smeared bases. Sprues are a bit harder to cut, but bullet weight is very consistent and bases turn out perfect. I cool the top of the mold, when keeping the melt below 700 degrees I hardly ever have to cool the bottom of the mold at all.

I have similar techniques for other molds. The Lee 2-cavity molds are a bit more tricky. Lately I have been casting loads of the .501-440 WFN. This is a big boolit, which means less meat on the mold. Casting with an alloy at the same temp, I have to cool both top and bottom of the mold after every pour, about 2 seconds on the top and about half that time on the bottom. Still keeping the sprue puddle consistent, about the size of an US quarter. Frosting usually starts to occur at the center of the base. Try to keep this area as small as possible, and don't let it reach the circumference of the boolit. Casting like this, I get less than 2 grains of variation on a boolit that drops at 450 grains. And this is from a 20 dollar mold.

This was a couple of examples on how I do my casting with a couple of my molds. Lyman and LBT molds require slightly different casting teqniques and cooling frequencies, SAECO's are pretty similar to the RCBS. It pretty much depends on the size of the boolit, as long as the melt temperature and casting pace is the same.

Good casting!