What temp do you cast at?

[grendel]

I cast a few slugs last night with two new molds.  One was a Lee 2 gang .429 @ 310 grs and the other was a Lee 6 gang .452 255gr.  According to my (also) new Lyman thermometer most of my casting was done at around 625F.  The WW alloy pored nicely from the ladle and the .45s filled out nicely and gave good bullets, however the .44 threw mostly wrinkled ones.  

My best guess is that the smaller mold and lessor (total) amount of WW in each mold caused the 2 gang mold to run cooler then the 6 gang.  I am guessing that I need to up the casting temperature for that mold.

Thoughts?  Suggestions? Up the temp?  How high?  Also, would it be worth my while to pick up a pound or two of tin/lead alloy to mix with my WW alloy?

The .45s will be used in a RBH .45LC and the .44s will be used in a Win 94/44.  

Thanks

Grendel

[Lloyd Smale]

probably because the 6 cavity mold is holding its heat a little better. I usualy cast at a temp that will allow for good bullet forming and that varys with mold material individual molds and air temp how many molds im running at one time ect. I try to keep records on what temps my molds like. One thing Ive found though is that the lee molds like to be cast hot. When I use them I usualy will only run one or two molds and cast quicky.  Being there alliminum and the blocks are so small they loose heat fast. I like to run the lees hot enough where the bullets that come out are a little frosted something i usually dont do with a steel or brass mold. Tin will help make nicer bullets but if you got the temp right its not neccesary in ww. I use it cause I have alot of it but have really never noticed a big difference.

I cast a few slugs last night with two new molds.  One was a Lee 2 gang .429 @ 310 grs and the other was a Lee 6 gang .452 255gr.  According to my (also) new Lyman thermometer most of my casting was done at around 625F.  The WW alloy pored nicely from the ladle and the .45s filled out nicely and gave good bullets, however the .44 threw mostly wrinkled ones.  

My best guess is that the smaller mold and lessor (total) amount of WW in each mold caused the 2 gang mold to run cooler then the 6 gang.  I am guessing that I need to up the casting temperature for that mold.

Thoughts?  Suggestions? Up the temp?  How high?  Also, would it be worth my while to pick up a pound or two of tin/lead alloy to mix with my WW alloy?

The .45s will be used in a RBH .45LC and the .44s will be used in a Win 94/44.  

Thanks

Grendel

[Cat Whisperer]

What temp?  Depends on the mould and the alloy.  Usually about 750 to 800 (measured).  I'll adjust it to cast well without frosting.  Sometimes one has to get it hot enough so that it frosts.

Too cool - bullets won't fill out right.  Too hot - frosting. fins, and lead wiping onto the underside of the sprue cutter (also from cutting too early).

Mould temperature is important too.  Haven't yet drilled mine to measure it.  Key is to keep a rythm to keep it constant once you've got the right combination.

A little tin helps fill out the mould, don't need a whole lot.

[Cheyenne Ranger]

I'm using the 20# Lee bottom pour pot.  With the Lyman them. I am right around 650--700*.  If it gets more than that I get frosted bullets--not a problem other than they're not shiney :grin:
Casting in a 6-gang 250 gr .45 LC mold I can cast about 5 times, set the mold aside to cool, add another lb of lead to the pot.  Then I switch over to another 6-gang mold for another 5-6 casts, add lead, go back to first mold, etc.  This lets the molds cool enough for me.
The 6-gang molds don't have to be the same, either; I usually use one in .45LC 200 gr and the other is .45LC in 250 gr.

[Kragman71]

My pot is a bottom pour,and I have a constant airflow over it from a window fan. That's probably why I do better at higher temperture:around 750 to 800 degrees.
Frank

[Tom W.]

But aren't frosted bullets more frangible than the "shiny" ones?

[Cat Whisperer]

If they are it's the first I've heard of it.  Hardness is affected very much by alloy and cooling - like water quenching.  But if they're air cooled they are about as soft as the alloy dictates.

I wonder if anyone has done a photomicrograph of the crystaline structure near the frosted areas?

[Leftoverdj]

Those moulds being new may have a little something to do with it. It's hard to get all the presevative off so they cast well in the first session. Jack that temperature up a mite and give it another try.

I'll take, indeed I prefer, a little frosting. I mostly use Liquid Alox for lube and feel it works better on a frosted surface.

I will also note that IMHO the Lee six cavities are enormously superior to the one and two cavities.

[Turk]

Leftoverdj Posted: Sun Apr 13, 2003 10:07 am    Post subject:  

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Those moulds being new may have a little something to do with it. It's hard to get all the presevative off so they cast well in the first session. Jack that temperature up a mite and give it another try.

Leftoverdj,

Try cleaning new or oiled moulds with Brake Parts Cleaner.  If I oil my moulds between sessions and I don't use the Brake Cleaner compared to other solvents I get wrinkled bullets plus it take quite a lot of pours to get a good bullet.  Cleaning with the BC I get good bullets real fast.

Be careful and wear eye protection when spraying as it can splash back.

Turk

[grendel]

I did not think to use Brake Cleaner to clean the molds.  I did however clean both of them with lighter fluid. before casting.  I suspect that I just need to jack up the temp a bit.  Next chance I get I'll give it a try at 700 to 750F rather then 650F

Grendel

[Tom W.]

Cat Whisperer,
The reason I mentioned it was because since I started casting way back when I saw articles saying frosted bullets weren't a good thing.I never saw an explanation as to why.
I see in my Lyman 47th reloading hand book that Frosted bullets, or bullets that break apart easily, are sign of a mould or alloy (or both ) that are too hot.  This I already knew, but I was the first time I have seen it in print as to why  frosted bullets aren't as good as the ones that aren't frosted. Far be it from me to say that they aren't shootable, as I have yet to hear a paper target or aluminum can complain about what it was hit with, but I have seen where a frangible bullet isn't the best to use on game, as there is the chance of it breaking apart into small fragments and not giving a quick  or humane kill. My son watched and commented on some I had loaded up for my .45Colt. We were shooting at 6inch stainless steel plates at the bottom of a clay pit. When hit with his 480 the plates caved in some, but there wasn't a huge spray of lead. When hit with my bullets, there was visible reaction to the overhanging trees, which were about 40 feet above the targets.

[Cat Whisperer]

Tom -
  Good observations.  I wonder what the mechanism is in the cooling process that, when the alloy and/or mould is too hot, causes the frosting and/or the frangible nature of the bullet.  Knowing this has the obvious results of being able to produce a quality product faster by knowing/controlling the process.

  You've done well in taking published information and combined that with comparitive observations.

  Is the frosting the only indication that the bullet is frangible?  Is there a way of testing for this condition (to see if it existst on bullets that were cast at a just sligtly lower temperature than that which produced frosting)?

  What combination of temperatures - alloy and mould - produce the frosted condition?  

Just some thoughts.

[lcicco]

Howdy,  My first time here.  If tin melts at 600 degrees and lead melts at 650 degrees, how can Antomony mix when it doesn't melt till it reachs 1100 degrees.??

[Cat Whisperer]

Icicco - that is a problem IF one were to add the pure metal.  Very often it comes alloyed with something else.  Further I'm sure that there are techniques one can use to get the job done (others will fill in here).

An interesting thing happens when you mix lead, tin and antimony.  The metlting temperature of the mixture is LOWER.  The lowest possible melting temperature is called the eutectic temperature, sought after in soldering where temperature can damage components; hence electrical solder is about 60/40 tin/lead to gain this low melting temperature.

The implication is, obviously, that the temperature at which you cast will vary also with the mix of your alloy, as well as the temperature of the mould and the size of the cavities.

The moral is that reading will bring to you much information that you'd never known before.

[Tom W.]

Ain't THAT the truth!

[cukrus]

Icicco, let me fill in a bit.  Antimony will form an intermetallic compound with tin, even if the tin is alloyed with lead.  I've used this principle to dissolve (not melt) antimony into lead/tin alloys just using charcoal as a reducing flux by submerging the floating antimony into the melt in the casting pot.  I doubt the temp needs to exceed that needed to melt the lead/tin alloy.  
cukrus

[Tom W.]

CW,
 I work with molten babbitt on a daily basis. Today I watched what I was doing. I turned the pot on at 0530 this morning and went about my tasks. about 1300 the pot was about 530 degrees. (It holds 600lbs or so)  The first 30 minutes all of my plates were wrinkled, as one would expect. but I watched and saw that the babbitt never got above 620 degrees, which is comparatively cool. by time i decided I had enough plates, the mold was so hot that I had to wait about 1 1/2 minutes between pours, and the babbitt was as frosty as could be. If the mold was opened earlier, the plates would break  or crumble. It appears that the frosting has a lot to do with the temperature of the mold, as once it gets hot, the temperature of the molten alloy can be decreased and still get good product. :eek: