Casting issues

[Chaparral]

Get your thoughts please. I am casting 405 gr for my 45/70 and ran into an issue. First runs had no issues once the mold was fully at temperature. I an using a Lee 10 pound pot, bottom pour. Kept temp on 9. After the first 100 on a brand new die I am getting flashing along the seam. I know this can happen if not fully closing the die but I am seeing it on about 90% now. Started seeing it on my 45 230gr rnfp as well. The lead is from wheel weights.

Thoughts on what I am doing wrong? What I can do to address the issue?

 

[dlbleak]

Is your mold getting too hot? Used to set mine on a wet towel for a second after each set. Seemed to help

 

[Okie4570]

I had a 480gr 4570 mould that would do that if I ran more than 50 or so at a time without cooling it.

 

[Calamity Jake]

Check the mold faces to see if there are flakes of lead stuck to one or the other .
if so gently clean it off with a tooth pick. Also check for burrs around mold half's.
and as already been said cool the mold a little, you might try lowering the lead temp

 

[Chaparral]

Too hot, wonder if that may be the case?

I did go over the faces with my fingernails after it cooled, did not get anything. I will double back for burrs with a loupes.

Thank you for the ideas!

 

[rickm]

I get flashing around my 30 cal molds from time to time but have learned that during a long session my hands would get relaxed and not hold the mold closed tight enough.

 

[Panayoti2]

What is your lead temp? My lee pot doesn't maintain temp well if you just set the number. I watch the temp gauge and end up turning it down. Are your bullets frosty looking? That's a sign that the mold is too hot. I run lee alum molds.

 

[Chaparral]

I am not constantly checking but nine on my pot is about right. Issue for me on looking for frosty is I am quickly quenching and not stopping after every cast to check. I have seen some which are a different colour but not too many. I will check temps going forward.

Thank you! Any other suggestions? I am new at casting in that I have not done thousands of rounds. Consider myself novice.

 

[Panayoti2]

I have not cast that many bullets. What I have done is mostly pistol. 45 acp, 9mm, 40. Some 8mm Mauser. 45 was ok. Had a lot of issues with 9 and 40. Ended up remelting about half due to defects. I had a batch of 9mm that was very accurate but could not duplicate. I ended up using the 9 mm bullets that would not shoot accurately in a 9mm in loads for 38 special. 125g. They shot great.

 

[Chaparral]

We’re your castings showing layers (cold mold or inconsistent pours)? Or did your flue end up as a cavity? Sorry, hoping to learn as well as diagnose.