bullet base is breaking off

[TheBabinator]

I was having some issues with wrinkles on my last run and so I increased the temp to 725 and it seemed to have resolved the wrinkles. But now I have a large amount of the bullets that have the edge of the base breaking off. I didn't notice more then usual sticking to the mould. It is a HP so they occasionally stick to the pins and such but I nothing like the portion that came out broken. They look like they are sticking to the mould but I didn't notice any major issues with that. Mould temp seemed hot enough. This did not happen on the last batch at 700 temp. Half way through when i noticed the issue I tried to slow down and then speed up for the mould temp with no real difference.

I am water dropping them.
Range lead with a bit more tin added.
NOE mould 358-135grn 4 cavity.


Any ideas?
121783

[ShooterAZ]

This sometimes happens to me when my mold gets a little too hot. I just slow my cadence a little and done.

[dragon813gt]

Surprised to see it's with pistol bullets. I've only had this issue w/ some 30 cal rifle bullets. The lead hasn't solidified enough. Just need to wait longer before opening the mold up. When I have this issue I cut the sprue at the normal count. But I increase the count before I open the mold.

[prs]

Use a damp bar towel to occasionally cool the sprue plate and add a few seconds to your "freeze time" before cutting sprue.


prs

[jethunter]

Bullets aren't cooling enough. Add 5-10 seconds more to the cooling time before you drop the bullets from the mold.

[10mmShooter]

as stated, too much heat in the mold, causes can be casting to fast, or alloy too hot, or a combination. The remedy is to keep alloy in 625-700 range and pace out your throws to give your mold time to cool. I use two 2-cavity molds, have two of all my molds, so when cast I can alternate and some times if one gets hot, you let it cool and use the other mold for couple of throws. Even with two molds and alloy temps around 675 when I cast I can still overheat the molds.

To keep the cool, I'll pick up one, pour, set, grab the other, pour, set. grab the first dump, set, grab the other one dump, set. Then back to the first to start all over. Its a lot of handling but it slows me down enough that I can get into a good rhythm, and I don't feel as through I'm purposely waiting on one to cool.

[paul h]

That's the tricky part of casting hp's, getting the mold and pins hot enough for fillout, but not casting so fast that the bases tear off when you drop them from the mold. With some practice you'll find the right temp and cadence for good bullets.

I'm still having a heck of a time finding the proper temp and cadence for my 400 gr .475" hp mold.

[TheBabinator]

OK, good I will try at a slower pace to keep the mould temp down. I just never had this issue with a similar mould with the .40.

Thanks all!