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View Full Version : Question on lee 457-405 and fill out?



Michael J. Spangler
01-04-2015, 08:33 PM
hi guys and gals.

so today i was pouring some bullets with my lee bottom pour pot, and my lee 457-405 mold.
the alloy is a sweetened up version of COWW cut equal parts with pure lead.

i found in order to get the mold to cast with nice crisp driving bands i had to run it really hot. all of the bullets were well frosted and if i dropped the pace, or took too long with pouring the other mold i was running in-between, it would start to round off again.
I wasn't sure if i was running too fast or too cold so i cooled the mold down and started from scratch. I ran lead through it at a good pace and watched for the bullets to have a nice fill out. once it was smoking hot with the all at about 750 they were casting well.
anyone run in to that issue with the lee 457-405?
the mold is pretty new, but had been run before and is nice and clean. i tried running the alloy slower through the bottom pour and a little faster. it didn't seem to make a difference.
i'm wondering if the new style lee molds are just a little too small for this boils design and they get cold too quick? also with the step down in diameter towards the bottom of the block i would imagine that would make for a less consistent temp through the mold.
maybe someone can shine some light on this issue.
should i just say "ah well" and keep casting hot to get the good fill out? or should i be doing something different? thanks in advance everyone!

aspangler
01-04-2015, 09:38 PM
Add just a touch more tin. I had that trouble with mine till I added some more tin. Turned the temp back to 700 and had great results. YMMV

Michael J. Spangler
01-04-2015, 09:57 PM
I'll give that a try.
If I were light on tin wouldn't I still have an issue no matter the temp? Thank you!

aharlow
01-04-2015, 10:08 PM
I have the same mold and cast with COWW +2% tin and they turn out really well. My alloy runs around 730 degrees and i use an NOE lead thermometer to make sure temps are consistent. A thermometer is worth it's wait in gold when it comes to casting. I also make sure when my ingots are melting in the Lee #20 pot to set my mold on the top of it so it is heating up also. Biggest problem is a cold mold so try and keep it hot and if you need to take a break put the mold back on the Lee pot so it stays hot or invest in a hot plate like some people do. You can put the corner of the mold into the alloy to heat it up pretty quick also. Keep a nice steady pace and don't stop to check every round that drops causing the mold to cool off. I usually throw back the first 3-4 cast because the mold is still not up to temp but will be after the first couple cast.
126364

aharlow
01-04-2015, 10:20 PM
I'll give that a try.
If I were light on tin wouldn't I still have an issue no matter the temp? Thank you!

Tin helps with mold fill out (like the edges of your driving bands )and since you are using a 50/50 mix of pure lead and COWW you have less tin compared to if you were using 100% COWW's. I would make sure its not a cold mold problem before tweeking the mix with extra tin. Run the alloy around 700-730 degrees and keep that mold from cooling down and see how it goes first....then if no good still work on alloy mixture.

Michael J. Spangler
01-04-2015, 11:26 PM
I just checked on my alloy. I made a blend with COWW and added tin and shot to sweeten it up a bit.
Going by the guidelines of our lovely alloy spreadsheet I figured I'm around 2% tin and 3% antimony before cutting.
So it's a little richer than what supposed COWW cut would give me.
I'm going to try to keep it hotter to see how that works.
I don't seem to have an issue wit fill out on the rest of my milds ranging from 125 RN for 9mm and 453423. I'm guess it's a heat issue. Makes more sense the more I think about it.