Priblem with boolit size

[RW460]

Hi all
I have had a problem with my lyman moulds casting to small a diameter. The 430 moulds cast about .428 this is with a lyman and a RCBS mould I have tried lapping the mould but it did not help. I have tried 600 to 700 degrees on the temp with a thermometer and still am not getting the results I would like, all help needed forgot using 90-5-5 lead

[bhn22]

Are you letting the mold get nice and hot? A mold that's not at full temp can cause undersized bullets. One quick thing to look at is whether the bullets have any wrinkles in them, and how well all the edges fill out in your bullets. I'd try a touch more heat too, around 750, but that's a personal preference. It just works better for me. Are you bottom pouring, or ladle casting?

[runfiverun]

that's the diameter my 429667 mold come in at.
it took me a few day's and a lot of test casting/heating and lapping to get it to .430.

[dondiego]

You can also Beagle the mold to increase bullet diameter.

[mdi]

I have found that my molds will cast slightly larger if the mold is good and hot and the melt/alloy is about 100 degrees over liquid, just hot enough to give good fill-out. IMO; a hotter alloy poured into a mold tends to shrink more (hot alloy = "expanded", fills cavity and during cooling shrinks more). Now, I don't have a degree in metallurgy, but I did stay at a Best Western, and this thinking works for me...