Voids in my bullets

Don'tkillbill

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I'm getting some voids in my bullets.

I think my temperature is fine but I will run my pot a little hotter and make sure my molds are hot enough.

Do you let your bullets sit in the mold for very long to let them set?

Could it be that I need to flux my lead more. If the tin separates from the mix should I add a little soldier or start over and ingot out my pot?
 
I assume you mean voids on the outside of the bullets? What do they look like? Are they circular like bubbles or more like a ribbon?
I've never had bubbles anywhere except the base and that was from oil in the mold. If it's ribbons around (or part way around) the bullet that usually means your mold and/or alloy is not hot enough.

*edit*
Some pictures I found with a random Google search

bands or ribbons - mold or alloy is too cold
badcast.jpg


bubbles in base - oil or other contaminate in mold
cast02.jpg
 
I suggest you try Charley Dell's method from The "Modern Scheutzen Rifle"- let the lead run over the sprue for a second or two after the mold is full. That ensures the sprue is the last to cool, allowing most of the voids to fill. It certainly helped my weight variation. More heat might help too.
Grouch
 
I ran a batch yesterday. My 125 grains were about + or - 1 grain. My slugs were + or - 1.5 grains. Most of the 45s were ok but a few were off by more than 2 grains so I put them back in the pot. I turned it up nice and hot and I also fluxed the lead.
 
Voids on the inside are checked by weighing and most bullets have them.

An interesting supposition, but it's literally the first time I have heard that. No two bullets will ever weigh the same - fill out is never exact and the sprue cutter is nowhere near a precision device. I'd say that +/- 1% variations in weight is "normal" and neither proves nor disproves the existence of voids. In fact I'd say that it's not possible for Joe average to prove that voids exist - you'd need some kind of non-destructive "MRI"-type machine.
 
Again -if you continue to pour for a second or two after the mold is full, or long enough that there very little to no shrinkage dimple in the hardened sprue, your weight variation is 'way better. I discard bullets more than +/- 0.2gr from the average weight, usually keep 90% of my 20:1 bullets and do much better with ww + 2% tin. I suggest you try this early on before you spend time and money on something less predictable and more time consuming.
Grouch
 
I have been casting for many years and when I get started the first 20 bullets are junk until the mold gets warmed up good. keeping your lead hot but not too hot also makes a big difference when casting. left over oil in the mold will cause the bubbles. clean your mold with an old tooth brush and dish liquid works well for this problem and dry after.
 
I have been casting for many years and when I get started the first 20 bullets are junk until the mold gets warmed up good. keeping your lead hot but not too hot also makes a big difference when casting. left over oil in the mold will cause the bubbles. clean your mold with an old tooth brush and dish liquid works well for this problem and dry after.

Totally agree here.For general shooting I inspect boolits manually under table lamp but for matches I weight them after manual sort.

I found that sorting lots by weight makes sense only for matches and only if you go anal with everything else like cases,sizes,OAL etc.Otherwise visual sort woks for me.
 
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