As soon as it's solidified but still hot, push it out of the chamber.
It is under sized when still hot/warm and will expand some predetermined amt (5%?) to full dimensions when completely cooled.
If you leave it in the bbl to cool, it expands and is very difficult to remove w/o damaging it.
I usually take a cleaning rod w/ slotted tip. Put a patch into the tip and insert from the muzzle till it's an inch or so from the mouth of the chamber.
Warm the bbl chamber area to get good fill out. Doesn't need to be any warmer than 100F or so. Then pour the cast. Wait a few minutes for it to solidify and push it out w/ the attached cleaning rod.
Unscrew the casting w/ tip from the rod if it won't just pull off of the tip.
