Shiloh Rifle Forums

Hey Guys...having a casting problem. In the photos below, you can see where one side of the bullet doesn't look all the way filled out, while the other side does. I've scrubbed this mold repeatedly with hot water and soap, and blown it out with brake cleaner as well. Damn near a whole can now been used on this thing. It also liked giving me the little "bug arms" off the side too (no fins), until I cranked the locking handles down hard enough to stop that.

The mold is a BACO 600 grain elliptical, shown against a 535 gr M3 mold for comparison. My initial thought is that this must still be some kind of oil contamination....should I try boiling the thing with some dishwasher soap?

16-1 alloy
RCBS pot set at 770 degrees (have tried everything from 755 to 805 degrees)
locking handles from Shiloh store
candle wax flux
ladle pour (10 seconds with slot filed and spout hole enlarged)


Strong opinions and swift kicks in the ass greatly appreciated!


Not filled out....




Other side filled out....

have you tried smoking the mold? Also when I use those handles (mine are aluminum) they really suck the heat out of the mold and I need to run 15ish deg higher to keep the mold at temp.
Also, is it the side with the sprue plate screw? I notice my bullets come out a bit crappy for a bit til that side heats up.

matt

I would find an old-fashioned typewriter erasure and completely rub the inside of the mold down. Then clean the mold interior with acetone. I would get a scientific-type hot plate to pre-heat the mold and set it at 850 - 875 degrees. I would rotate the mold quickly as you can, and once it is fill with ladle still in the fill hole, give the mold a couple of light quick taps on the edge of the pot. Let me know if that works.

Temperature and clean vent lines. Mine look like that for the first 8-12. Pour and dump as fast as you can to start with (spue hardened + a couple seconds). Slow down once good bullets are made. Check sprue plate tightness. Some moulds work best fairly tight others not. Mine are usually pretty loose. You only need to smoke the mould if it's not releasing.

HI sounds to me like you smoked the mold with a candle I have never smoked a mold in my 26 years of casting no need for it unless bullets will not drop from mold You need to pre heat the mold really well and the first few will still not be worth keeping

Dross residue?

Before filling the ladle, I push the dross from the melt to one side. I also skim the dross from the pot often during a casting session. If I do not remove/push aside the dross I have had bullets with the same imperfections.

I had a good talk with an experienced BP shooter and checked out these responses, and it seems I just needed to adjust the tightness on my handles and heat the mold up better. I had been pre-heating it on a low setting, moving it up to medium for about 30 minutes or so seemed to cure all ills. Plus, I cast at a faster rate to help keep the mold in the zone.

Funny how double checking the basics solves so many problems. Got a hundred good bullets this afternoon cast and sorted. Thanks for all the help, it's getting close to driving day for the Q!

Skim and flux your melt

A good indicator that your mold is hot enough is found by timing how long it takes for the lead to solidify on the sprue plate. 6 or 7 seconds will usually give good bullets.

Ole Pizen Slinger

Flux and Skim in that order
beltfed/arnie

I preheat my molds, but I also leave the first bullet in the mold for several minutes to let it heat soak. Sometimes I pour a 2nd and let it soak again if I don't get the next bullet to form well. That usually ensures the mold is hot enough, and I can go from there with no issues.

marlinman93 wrote: ↑Thu May 25, 2023 8:49 am I preheat my molds, but I also leave the first bullet in the mold for several minutes to let it heat soak. Sometimes I pour a 2nd and let it soak again if I don't get the next bullet to form well. That usually ensures the mold is hot enough, and I can go from there with no issues.

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