Look at these boolits

[leadmonkey]

And tell me what I'm doing wrong, please. They're 9mm from a Lee 356125 mold. I'm using pure clip-on wheel weights at 750 degrees according to my PID controller (I've checked it against several other thermometers, and it is correct). I heated the mold on a hot plate to ~400 degrees according to my infrared thermometer (It's hot enough to discolor the steel on the holder).

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[Went2kck]

Looks like it needs to be fluxed some more. Appears to have some impurities in it. Those still could be shot I do believe with no problem. Weigh them and shoot them.

[tomme boy]

How many have you cast through the mould? It looks to me you need to clean the mould better. I have had 2 moulds do this. One was a Lee and the other was a NOE

[ShooterAZ]

Try casting them at 700-725*, maybe add a little tin to your alloy. Sometimes you just have to adjust temp a tad to get beautiful boolits. Keep notes of your alloy & temps.

[Yodogsandman]

Mold too hot. Run your pot at 700*F to 725*F.

Every mold wants a different temperature. Try starting off with the mold temperature at 350*F.

New mold? Not cleaned of all oils yet. New molds sometimes take 3 or 4 cycles of hot and cold to start casting good boolits.

Maybe sprue plate lube contaminating the cavities.

Sprue cut off is high. Waiting too long to cut the sprue or the sprue plate is too loose. Maybe lead build up under the sprue plate or on top of the mold is holding the plate up.

Did boolits get better as you cast? It looks like you started off with a hot mold that took a long time for the sprue to cool and as the mold cooled, the boolits got better. Like you stopped casting just as the mold temperature stabilized. Keep casting till the lead is gone.

[mozeppa]

yeah i noticed as well that every mold has its own personality.
all of my molds are 4 cavity.

my 25 acp mold likes 725 degrees
whereas my 357 mag 158 grain mold likes 660 to 670 degrees

230 grain 45 acp like 680 to 690

this is MY findings with MY alloy
it may not work for you.

just have to pour a lot to see what it likes.

[Eddie17]

I'm going to agree with Went2kck, you need to clean you lead out.

[runfiverun]

yep clean the alloy.
the top 2 look good the bottom ones are frosted.
once I get my mold going well I turn the alloy temp down to about 700.
then I go into cruise mode.
I am not hurrying I'm making deliberate calculated moves and making concise counts before breaking the sprue.
this keeps my mold in a consistent temperature range and I get a known rate of return per hour of casting.
like 720-960 boolits an hour from a 4 cavity lyman.

[Yodogsandman]

The little holes you see on the surface of the boolits are inclusions. They're a very minute, microscopic carbon dust that's in all lead (cleaned and fluxed well, too). They normally only show up when the mold and alloy are way too hot. Most times, only on one side of the mold, too. The lead stays in a liquid molten state long enough for them to migrate to the outer surface of the boolit. With a cooler mold, the liquid molten lead freezes more quickly at the mold surface. I think they are carried along with the tin, maybe they're bits of oxidized tin.

[runfiverun]

oxides usually get on the surface of the alloy.
750-f would surely contribute to more of them forming and tin especially starts oxidizing faster at that temp.
usually the black gunk will try to ride the heat currents to the top and stay there bit it easily trapped along the walls and bottom of the pot and the only way to get it off is to scrape it.
the oxides are easily returned to the alloy by using an oxygen free barrier and a little heat.

if you use a lot of saw dust in your alloy for fluxing it is common to get that carbon in the alloy and it's pretty hard to get back out.
the thing is you want the carbon in the alloy it helps the sbsn chain form better through a process called carburization it is however a royal pain to get back out of the alloy once it gets down on the walls and bottom.