Casting temps and boolit size

[hickfu]

I have been casting for around a year and a half now and was talking to a guy that used to cast and he said that the temp at what you cast at will have a bearing on the size of the boolit...???????

Is this right or was he :kidding:


Doc

[pull the trigger]

I notice a slight difference as my lee mold heats up, or seems to overheat, they need to be sized as it gets warmer, but it the early stages they are small enough to just TL and shoot, I think?

[cbrick]

Depends partly on the alloy but yes, heat can change final diameter a little because the hotter it's cast at the more shrinkage there is as the boolit cools. Normally minor differences though measured in tenths not thousands.

Rick

[pdawg_shooter]

When my mold get hot enough to drop frosted bullets they are a bit under sized.

[williamwaco]

See:

http://www.reloadingtips.com/pages/exp_Bullet-diameter-vs-temp.htm

[44man]

It is not so much that hotter lead shrinks more, it might, but the cavities get smaller once hotter then needed.
Many look at the cavity as a hole, it is NOT a hole, it is half a hole in each side. As the blocks expand, they expand towards the half cavity.
Sometimes I make a cherry too small and the boolit is too small. I get the mold HOT and drop the cherry in to turn with a wrench. I will remove a lot more metal, bringing the mold to size. I also get a ROUNDER boolit.