Casting problem

victorj19

I'm casting 1oz slugs using a Lee mould with the center key feature. Half of the slugs have voids in them. I'm using virgin lead and have tried various temperatures (Lee pot settings 6.5 to 9).

There must be some difference between using virgin lead and harder alloys since I can cast heavier bullets with an alloy.

Any advice?

Thanks,

Jim

Thanks everyone. I'll add a bit of wheel weight to the mix and smoke the mold (I usually do but skipped it this time). I already tried high temperature but will again.

bpost

Have you pre heated the mold?
Are the mold vent lines clear?

If you pour the lead at slight angles on the sprue hole it can help push air out.

rufe-snow

A very small percentage of tin mixed with the lead is usually recommended. It's been years since I've don any casting. But as I recall a certain percentage of wheel weights or 50/50 solder is melted in the pot with pure lead, so that the bullets will fill out the mold and cast OK.

perry shooter

Pure lead needs both hotter melt temp in the pot and Mold needs to be preheated much hotter also. Turn the heat up on pot than cast and discard the first ten back in the pot as soon as they are poured this will transfer heat to the mould block

charliemeyer007

+1 perryshooter Mold need to be clean, free of oil. If using a ladle pour the full amount over the spru. Pure lead is a lot harder to cast.

trapguy2007

Take a kitchen match and light it and smoke up the inside of the mold .

That solved the problem for me .

fordsix

big slugs need hotter temps

Hawk Carse

Do NOT put zinc in your bullet metal.
It is one of the most common and nastiest contaminants around.

geeguy

I use the Lee slug mold quite a bit and it states to USE pure lead. I am not a highly experienced caster like some here, but I use the max heat and dip the corner of the mold in the lead for about 30 seconds (after the match treatment). Never had the non-fill condition, so I can't help there.

Good luck.