Havin'g an isssue with my boolits

[Griff]

I have been having a issue with casting lately. Last year my 35 year old Lyman Mag20 quit heating. So, the power unit in our house okayed me to buy a new pot. I got the new Lyman Mag25. Has a built in PID. At the same time I bought a Lee Pro IV with a PID that I got in trade for the old Lyman pot.
I really like the Mag 25, it's stable, and although I've cast a whole bunch of my 45-225-CAV bullets... without an issue. But, in casting some .30-30 GCFN I started having "folding" problems. They've started to lessen, as I've upped the meld temp, but... now I'm casting at 750ºF. Seems way too hot. And still getting folded bullets from both molds.

I haven't tested any to see of they're very hard... but I generally let the pot get low, then add the same mix of 6 parts WW to 1 part Linotype. I generally put the two molds I'm going to work with on top of the pot to warm as the meld is brought up to temp. Then I'll run one mold for about 6 - 10 fills dumping all the bullets back in the meld to get it hot, then start working the second mold into rotation to get it hot enough to run bullets...
The Saeco #316 has started to produce better bullets, but the new RCBS 40-300-CAV mold I got a few weeks ago is still producing "folded" noses and not quite filling out the lube grooves.

While these from the Saeco 316 are not the best, I'll probably go ahead and use 'em, in our short range target matches, at least until the meld in the pot is gone. Maybe I'll do hardness test on them tomorrow and see if I have gotten too much Lino in the pot. Then I'll put new lead in, and watch the addition of Linotype more carefully. With only 50 lbs of WWs left, I'll get scrounging soon! I've never had this problem before and am wondering if anyone else has, and what they found the cause was. Sure hope it's not something else.

[Yodogsandman]

Run one mold and run it fast. Your molds are too cold.

[Tenbender]

I was having problems with a NOE 360-180 WFN wrinkled boolets. It is a 5 cav. mold and I was running to cold. I kept turning the temp up until I reached 750. That is from my Lyman thermometer and I don't think it is accurate. Anyway I have to run that mold very fast and at 750-800 degree's.
If I let it sit even 30 seconds I can't open the mold. Even at that temp my boolits are not frosted.
As far as fillout, I add 2% - 3% tin with a 50 50 alloy . This is the only mold that I own that needs that much heat ?

[Bzcraig]

Yup, cold mold..........

[osteodoc08]

Cold mold. Get a hot plate to preheat the molds.

I also keep a handheld propane torch at my bench and can heat a mold up a touch more of still having wrinkles, just be cautious to not overheat the mold

[runfiverun]

guess I will say cold too.
or your dribbling alloy into the cold mold.

[OS OK]

I think the sprue plate is the coolest part of the mold...therefore I believe that you can quench the Pb by ricocheting the Pb off the side of the sprue hole. In other words...pour as directly into the center of the hole as you are able to do without the Pb actually contacting the sprue plate.
If you pour from the farthest end of the mold and have it tilted back so you can see the pour better...sometimes when you allow the sprue to build a little before moving to the next cavity, some of the excess Pb overflows into the empty cavity that is to be poured next...just a fraction of a second before you slide the mold forward to fill that cavity is all it takes...that will give a wrinkle too.
As far as I'm concerned 750*F. is not all that hot when it comes to long boolits and large heavy casts.
Pay attention to the actual sprue cut. It will start to smear-cut as the mold is running on the too hot side...the proper cadence will develop quickly as you watch that cut and the fact that they are filled out perfectly at the base...not slightly radiused but square edged, 90* bases.

Could be I've said too much and you are aware of most of this...it's just a few things I watch.

[robg]

Swirling the lead round the sprue plate might help rather than directly into the mold .how is the flow rate from the pot?is it fast or just a dribble?

[swheeler]

cold mold, preheat them and cast faster

[CPL Lou]

Oil contaminating the mold maybe ?

CPL Lou

[runfiverun]

I initially thought oil in the top pictures too.
but there is just no part of the boolit that is good.
oil usually shows up here and there or in the same spot over and over.
it can be cured easily enough by a good scrubbing with a degreaser.
and some molds just need a few heat cycles on them to do their best.
but even those will show square bands and such with just some minor areas of wrinkling.

[Griff]

Mold wasn't getting hot enough. Fluxed with a bunch of wax, and a little bit of contaminates came up, but not enough to really cause the issue. Casting with just the single mold today... produced a bunch of good boolits:

I didn't even take time to inspect each drop as it came out... trying to run the mold faster than I usually do... you can see some of the early ones in the upper part of the pan... those'll get sorted out and remelted.
Nice crisp corners and no "folds" in the nose or elsewhere.

After I'd ran 10 or 12 dumps I started noticed that I had less and less "swirl" showing in the base after cutting the sprue off. Then, a few drops later, it was gone... an looking at the noses, smooth and silky looking. I might have some dust in one half, will inspect it after everything cools off and I drop out what in there... started getting towards the dinner bell, so it was quittin' time!
Next to drill out the set screw on the Saeco mold and get a new one in there! Always something... no?

Anyway, thanks for all the input... it was as I hoped, but feared not... I probably need to cast more often...

[WHITETAIL]

Griff, Hot and fast!!!
I have been making boolets for a long
time now. And still have a large learning
curve. But if you listen to these members
they will set you on the right path.
God knows they helped me a lot.