Home Forums Reloading Bullet Casting casting problem

I've cast my own bullets for years. Recently I was given a Saeco melting pot with the spiget (?) on the bottom. When I fill my bullet mold, most of the bullets come out with a cavity or bubble around the area where the sprue is cut off. I've gone back to dipping the lead out of the pot manually and filling the mold that way. The bullets come out perfect. What am I doing wrong?

Check to make sure your vent lines on the mold are not plugged, don't hold the mold tight against the spigot, make sure you have a good sized sprue, ensure the mold is level while filling from a drop spigot. Can't think of anything else off the top of my head that could cause that but all of those might.

I agree with stocker. I suspect that you are tearing molten material from the spru when you remove the mould from the spiggot. You may not actually see the material but you may be drawing it from internally around the sprue. I'd try holding the mould away from the spiggot a bit.

I was indeed holding the mold right up against the spigot. I'm used to doing it that way what I pour manually. I'll try letting the lead drop in a little. Thanks for the advice.

In foundry circles, that cavity is called a carrot. It is shrinkage that is not fed from the sprue. Shrinkage is exacerbated by high metal temperature. Holding the mould against the spout a little longer usually cures the problem, as does puddling a blob on top of the sprue plate.
Cheers from Grayest California,
Ross