Best temp to cast lead bullets

[mrappe]

I just got my thermometer from rotometals. What is optimal temperature?

[Ole]

Depends on your alloy and what your molds like.

I like 720-740 with most of my Lee molds, running 2/1 WW/PB alloy.

Pure lead = hotter.
Lino = much cooler.

[sagamore-one]

I use a variety of moulds. Some like it hot... some not so hot.
When I'm in "production" mode I run 2 H&G gang moulds ( 8 or 10 cavity) with the melt temp at 875 with lino. Most other casual casting is with cooooler temps.
When I run into zink infected alloy I crank the melt temp way UP.

[lwknight]

That is just something that you have to work out for yourself.
I only have 8 molds , some steel and some aluminum and I never need higher than 700 degrees for any alloy except pure lead and 750 was just fine for that.
I get the most production at 650 on my 6 bangeer 240 grain 44 mold with WWs and 2% tin.

[JonB_in_Glencoe]

mrappe,
I am in the same boat you are...I just got a Lyman lead thermometer.
I am chomping on the bit to try a few things.

what I want to try is getting the mold up to temp,
then backing down the alloy temp to 675ish.

here is a great conversation in that regards...yeah it's long,
but try to get through the first 50 comments. Lots of valuable info.
http://castboolits.gunloads.com/showthread.php?t=93447
Jon

[cbrick]

When I'm in "production" mode I run 2 H&G gang moulds ( 8 or 10 cavity) with the melt temp at 875 with lino.

It's a shame that what little tin that's left in your lino can do nothing to inhibit oxidation and reduce the surface tension of the alloy going into your mold. The very reasons that it's there.

On the the other hand, if your happy with your results you should certainly continue but in the interest of new casters that sort of info will serve only to greatly increase their learning curve.

As JonB said, the reasons are posted in this current ongoing thread. http://castboolits.gunloads.com/showthread.php?t=93447

Rick

[Tenbender]

I'm finding that high temp. say 725 or so cast a frosted bullet. 650 to 700 cast a bright bullet. Now having said that, The bright bullet will be lighter in weight than the frosted bullet ? I don't understand but for my 150 gr Lee mold to cast anywhere near 150 the bullet needs to frost. The bright ones cast around 142 ?
I'm new here and new at casting so any explanation will help me.
thanks

[cbrick]

Welcome to CastBoolits Tenbender,

You didn't say what your alloy is but 700 should be fine. You need only cast faster at that temp to get the mold temp up and keep it there. Aluminum cools very rapidly, don't inspect your bullet while you mold is cooling off, keep casting and 700 degree alloy temp will keep your mold at a fine casting temp.

The cooler mold will always be your lighter bullets. I pre-heat my mold on a hot plate, even so I don't keep the first 8-10 pours because the mold is not yet at proper casting temp and those first bullets will be the lightest ones of the session.

Rick

[cajun shooter]

I was first taught casting by my mentor in 1970. He was the owner of a gun store in Baton Rouge, La. and the store had a full service type store. We had a gunsmith off site that did all the gun repair problems and also had one of the best stock finish men I've ever seen. We offered store brand cast bullets in addition to those produced by Speer whom we were a jobber for.
I was taught to preheat the H&G molds on hot plates while the alloy was melting in the several Lyman and Saeco pots. I had at least 2 molds per caliber and each mold was 6 or more cavities per mold. We had 4 8 cavities mold for the .357 bullets we casted.
I was taught to take 3 kitchen matches to smoke the cavities of new molds after cleaning, it seemed to work then.
I cast 1-20 bullets for my BP shooting and I keep my Wagge Pot set on 750 for my casting. My bullets are bright with great fill out. I use two 3 cavity Accurate molds to cast my designed bullet for the 44WCF. I have Tom make my molds out of the same mold block that is for 4 cavity molds as this gives them more aluminum to maintain the correct casting temperature. Later David

[mozeppa]

i have a new magna 90 pound pot that runs on 220v.
it does melt 90 pounds to casting temp in 35 mins or less!

it also is governed by a pid temp controller.

yesterday when fully up to 715 it ran good ...and i wondered what the threshold of good melt/mold temperature
was.

so... i re-set the pid down to 680 degrees.... it still cast quality boolits at around 695...will be testing again as
the temp hadn't had enough time to cool to 680 yet.

but at 695 all ran good and they seen to drop from the mold easier....i also noted that at 695 the sprue puddle
frosted over much quicker and was stiffer to cut. (i think this is good as i don't get the curved smear of lead on the top of the mold blocks
themselves.

i was casting for .380 caliber and the weigh about 105 grains...the temp. may be different for larger calibers.

and at this point for this mold and caliber ....i haven't determined what the lowest temp is and still get quality.

as soon as the other molds (7) get here i'll be doing a more comprehensive study on temps.

[georgerkahn]

I am ever so fearful of dreaded zinc melting in my mix, so I always start at the LOWEST temp that will fill mould cavities. But, then if boolit to boolit uniformity is not where I want it, I crank heat up a bit. My last batch (RCBS 2-cav mould for .35 Rem) seemed to work best at 760*, PID controlled RCBS Pro-melt Pot. My mix was COWW + RotoMetal superhard + Tin (18:1:0.50)
What keeps the bullet-casting hobby from ever becoming boring for me, is every session, every mix, is slightly different. Even same mix, temp, and mould from day to day...
I'd suggest you start as cool as possible to have a mix which gives a good fill-out; after visual inspection, weigh maybe 20 to 25. If they all "pass" whatever tolerance YOU elect, great; if not, perhaps raise temp a few degrees. I understand tin oxidizes greatly as temperature of melt increases, as does the chance of getting dreaded zinc in your mix. MOST important, too, imho, is you flux sufficiently. I have "corrected" a few problems not by changing melt temperature, but by energetic fluxing.
When you find what works perfectly for you, then record that temperature.
BEST!
gorgerkahn

[robg]

depends on mold they choose what they like,all different like women.some like it hot:bigsmyl2:

[bobthenailer]

for iron and LBT & Mountian aluminum 2 to 8 cavity moulds 650 to 700 degrees, for lee moulds 750 degrees !

[montana_charlie]

I run ... the melt temp at 875 with lino.
Linotype is molten at 465 degrees ...

[geargnasher]

Run the pot temperature at what's best for the ALLOY, regulate MOULD temperature for what's best for the MOULD using casting pace, pour rate, and sprue puddle size. These are two different things entirely, and it's very important to understand and think about the difference. JonB and Rick posted links to the thread that will help immensely, IF you're an "input" sort of person instead of "output only".

Gear

[41mag]

Yep like mentioned, it is usually best to start out low, 680'ish and work up. I use a PID controlled Lee pot. I started out using the standard lead thermometer and found I was constantly chasing my temps. One minuted I am barely getting the sprue cut the next, I'm pouring frosted bullets. That said I was learning while using a Lee 452300RF 6C mold which also dropped the level pretty quick.

Once I got the PID set up and running I found that with that mold hitting 695 with a preheated mold was the sweet spot. Usually the second pour was quality bullets which were all the same diameter and ran within a couple of grains high to low in weight for a full pot of bullets.

Then I got a brass mold and that all changed, then I picked up several steel ones and again adjustments had to be made. For the most part however with the alloys I use between 685 and 740 I can pour out great bullets from all of the molds I have.

One last thing that I have found, the larger the cavity, like 44 and up, the hotter the mold will get and stay when your hitting a good pace, so you have a little wiggle room. Drop down to .358 and smaller, and well you have to run hotter or pick up the pace quite a bit to keep the mold hot. Then there are the HP molds, which are a critter all unto themselves.

[Beagle333]

I don't think there is just one number. My aluminum molds run toward the cooler end of what has been mentioned and my MiHec brass HP molds run toward the hotter.

[largom]

As said boolit size, mould material, and alloy changes things. I can't run my 22 moulds at the same Temp. as my 45-70's.

Larry

[fredj338]

I try to stay around 650deg +/-, with range scrap or equiv. Some alloys will need a little more heat to flow well.

[altheating]

62-70 degrees is best. Any warmer and I start to sweat.

[geargnasher]

62-70 degrees is best. Any warmer and I start to sweat.

:drinks:

Gear

[Rodfac]

I'm running a 20# Lyman bottom pour, casting straight WW + as little tin as is possible for fill out. 700 degrees seem to suit my brass and iron molds well, but Lee's aluminum is 20 degrees cooler. I use my casting rate to keep mold temperature so that the puddle of sprue hardens in 3-5 seconds, then open just after the 'color' change. I use the time waiting for this to happen by dropping the previous sprue cutoff back into the pot. I flux with straight sawdust, using a piece of pine cutoff to vigorously stir the pot, every 50 boolits. I also very rarely skim off the dross, and keep a 1/4" - 3/8" thick layer of sawdust charcoal on the surface which I believe helps minimize tin oxidation. As a result, I use very little tin whatsoever, and get good fill-out with more or less straight WW's.

Rod

[Loudy13]

So I got my thermometer yesterday and fired up the pot at the usual setting that I have been using. I was surprised to see my setting of 775 on my lyman pot yielded a 600 degree reading on the thermometer. Which every time I add lead it drops about 20 degrees for a couple minutes. From what I am reading on here looks like I need to bump my temp a little. My easiest mold to fill and get decent frosty bullets with COWW is a lee 230GR TC/TL in 45, a little more temp may help fill some of the other molds I have more consistently.

[Dusty Bannister]

Quote: I was surprised to see my setting of 775 on my lyman pot yielded a 600 degree reading on the thermometer. Which every time I add lead it drops about 20 degrees for a couple minutes. From what I am reading on here looks like I need to bump my temp a little.

Or better yet, find some one with a PID controlled pot and compare the reading of your thermometer and the PID. If not that, melt "pure" lead and as it just starts go become solid it should be about 621 F. Then note the difference in readings.

Since you were casting at your setting 775, which the thermometer showed as 600 degrees, I suspect the thermometer is off or the lead would not flow.

[Loudy13]

I was thinking of the doing the pure lead melt to check the temp...don't know anyone that has a PID so that isn't an option

Thanks for the help

[John Boy]

... Different calibers with iron and aluminum molds - Cast between 710 to 730. If high lead content - cast at 680. The key is a 5 second pour and a 5 second sprue puddle frost = filled out bullets than are not frosted