How hot do you cast?

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22to45

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I do not have a pyrometer, but I have tried from quite cool to very hot and cannot get 30 cal Lee 200 grain bullets to cast without a wrinkle on one side, about a quarter of an inch from the front of the bullet. I have casted as fast as I can go to try and heat up the mold, it gets better but not perfect. I am using a Lee melter, and it is one of the ones with the pour valve at the bottom. Any ideas?
 
My bullets are shiny, I am casting wheel weights plus 2% tin, I flux with parrafin, Close to the front of the bullet I get an both vertical and horizontal lines on the surface of the bullet indicating a cold lap in the cast. I have turned up the heat until the surface of the melt turns blue, and it still does not give correct looking bullets. I Lube with lee alox, and the first time I tried the 30 cal ones you could just keep them on the page at 25 yards. Loading is another matter, of course, these are gas check bullets, and I probably tried them too fast, at 2300 fps. from a 30'06 '17 enfield. I would like to get perfectly shaped bullets before I try to find an accurate load.
 
Clean mold and then clean it again, maybe use break fluid as it leaves no residue. Preheat mold on a hotplate, do not use any mold prep. unless you use"Bullplate" and then very sparingly. If this doesn't help, you need more heat and speed, unless mold has flaws. I found that wheelweights are the poorest material to use for casting and I haven't used them in many years. In regards to accuracy, you say it is a gc mold, but are you using GC's? Quite often I keep and shoot "rejects" and they shoot just as well as any others, so your scarred bullets should still shoot!
 
Thanks, that was the insight I was looking for, I will clean the mold. I am using hornady gas checks and the lee 309 sizer. Perhaps this aft I will get a chance to photo a bullet. I tried smoking it once with a match, but that did not improve things.
 
22to45 said:
I degreased the mold, and cast a few to see how they looked. Now they are different, but still not right, any suggestions would help. I cast them quite hot

http://i872.photobucket.com/albums/ab283/22to45/cast bullet pic/200gaftercleaningmold.jpg
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From the picture, it is evident the mold is still dirty. How about boiling the mold for 20 minutes. That is what I do before using any of my Lee molds.

A buddy uses VARSOL then compressed air...works too.

The bullets look shiney so I think your temp is just about right. WW usually doesn't flow very well into all the mold details, so I add .5% tin from 50-50 tin solder bars (get higher percentage tin if you can find them). Frosty bullets indicate temp is too high. I like a little dull finish (not frosty) because I believe ALOX will stick better, but what do I know?

Another thing, I smoke each cavity thoroughly using wood stick matches. It aids in releasing the bullets. Helps make the whole process go smoother.
 
Your aloy may be too soft for your velocity possibly water quenching them to increase the "Hardness" might help ! Have you slugged your bore and are you sizing 1-2 thou over groove diameter ?
 
blaser.306 said:
Your aloy may be too soft for your velocity possibly water quenching them to increase the "Hardness" might help ! Have you slugged your bore and are you sizing 1-2 thou over groove diameter ?
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Funny you should mention that, as I just measured an "as cast bullet" and it was .307", I could push it through the .309 sizer with no resistance. Ok, why does the mold cast undersized bullets. It does not even touch except to put the gas check on.
 
Dip the corner of the mold in your lee pot till the lead won't stick to the mold block then try casting.
Wheel weights get slushy at 463 degrees and molten at 505 degrees.
If your mold is to hot you will get dull finish bullets if its too cold it won't fill out right.
 
I thought using more lead DECREASED the diameter of the bullets. Pure lead casts smaller than WW and WW are smaller still than Lynotype. The slugs weigh more with pure Pb but are actually smaller in diameter. If you do a good degreasing of the mold and still have problems look with a magnifying glass to see if your mold has the vent lines blocked up. Don't hold your mold to close to the spout, if you don't allow the air to come out of the mold (plugged vent or spout tight to sprue plate) you can't fill it properly. Try holding the mold slightly further and perhaps even on a slight angle to the spout. To be honest (I'll probably get thrown out for this) I've found that using a LADLE gives me better bullets than bottom pour. FAR less variation in weight and almost no visually faulty bullets once the mold is heated, 8-10 casts. Good luck.
 
The question was, how hot do you cast?
Old time sawmill and planer equipment had lots of bearings that often had to be repoured. The bearing metal was called babbit and it was very similar to the alloys we cast for bullets. The old millrights and workers of the day had a method for testing temperature of their molten alloy.
They took a splinter of DRY wood, with pine being a favourite, dipped it in the molten metal, counted to about three and pulled it out. The metal should not be so hot as to set the wood on fire, but the splinter should come out a golden brown.
I use this method for testing the temperature of the alloy when I am pouring from my Lee pot. With a bit of practice it is very accurate.

(This tip is for free, but might have to charge for any more lessons!)
 
You anywhere near a Princess Auto?

They sell a cheapo digital multimeter that comes with a temperature probe (K type thermocouple).It reads only in Degrees Celsius, but it only takes a few minutes to print a chart up to get a decent conversion.

Talk nice to a welder and have the end of the thermocouple welded into the end of a length of stainless steel line. Split the wires apart, thread them through the tube, crimp them into the end of the tube with a vise or Vise-grips, then take the unit in to have a bead run across the end.

Makes a great tool for $10(on sale price) and whatever the two minute weld sets you back.

Or drop a few more bucks and buy a thermometer that is set up for casting. It does not need to be decimal places accurate, but repeatable is good. Once you find the temperature that works, anyways.

Or buy a probe already built. Take a look at Auberins.com. Some pretty good stuff there for not too much spare change.

I'd suggest clean clean clean for the mold. Hot soapy water and a scrub with an old toothbrush. Rinse. Repeat. Dry. Skip the smoke, skip any other possible sources of contaminants. Save the smoke for IF you have issues getting the bullet to drop.

Metal is clean? Pot has been cleaned out since the WW were melted out? I bead blasted out the inside of my old Saeco bottom pour. It behaved much better afterwards. A good scrub out with a wire brush would go a long ways, if there is crap stuck to the sides or bottom of the pot.

Get a thermometer, though. Then you know at least close to what temperature you are at.

I got great looking bullets out of my 22 cal molds on straight WW at 600 deg C. (1100F!) indicated on my thermocouple. A tad warm. Very frosty. Some flame issues when fluxing...piece of dry lumber split down to stir with. No trouble keeping the mold warm, though. :D Casts well at around 350-380C for me. Dropping below 350 makes for wrinkles and folds.

Cheers
Trev
 
That's one good reason to buy quality molds, they drop bullets the size that they are supposed to, and if they don't; you can send them back to be made larger. The harder the alloy, the larger the bullet drops but only by .0005" or so. You would be surprised at the number of molds that are undersized, recently I've had a few RCBS molds that were undersized.
 
22to45 said:
I do not have a pyrometer, but I have tried from quite cool to very hot and cannot get 30 cal Lee 200 grain bullets to cast without a wrinkle on one side, about a quarter of an inch from the front of the bullet. I have casted as fast as I can go to try and heat up the mold, it gets better but not perfect. I am using a Lee melter, and it is one of the ones with the pour valve at the bottom. Any ideas?
Click to expand...

As mentioned earlier, oil or grease on the mold may cause the wrinkles even if your mold is hot enough. Try brake cleaner, Varsol, or simple boil the mold for 20 minutes.

A previous post by ben hunchak mentioned that your bullets are wrinkled because the mold may still be too cold.

I also use a Lee 20 lb bottom pour and set the thermostat to 5.5 (maximum is 9 on my melter. The thermostat is not a precise temperature control and the numbers only give you a reference, you may need to set to a different number).

I preheat the mold (Lee 6 cavity .451 230 grain) about one minute by dipping one corner in the melt. Then I go through 3-4 pour cycles before the bullets come out smooth. Smaller bullets like 124 grain 9mm .356 require more cycles to heat up the mold.

Are you using a single, double or 6 cavity mold? In the double or 6 cav, are all the bullets from all the cavities wrinkled?
 
It is a single cavity mold. I will try some of the ideas here, I will have to get some lead, hopefully tomorrow, and I will try it again. I was so hoping that the mold was machined too small and not that my technique was wrong. I do intend to make it work though. No doubt there will be a bit more trial and error.
 
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