Lee six-cavity warped, how to fix.

[dahermit]

I am a volume caster...I use two (yes, two) Lee 358-125-Rf molds at the same time...one cooling, one being poured. I pre-heat them on a hot plate as my Lee pot (I use an open-top Lee, because ladle pouring what how I started and never could get used to bottom-pour.

Over the past few years I have had a couple of six-cavity Lee molds warp and produce bullets with fins on them. One of my molds has taken to doing that again. When I swing the sprue plate aside and hold the mold up to the light, I can see very slight daylight coming through, except for where the alignment pins are located.

If I could set either side (male or female) slightly deeper, I am sure that I could reduce the gap in the mold if not remove it altogether. So, what I am interested in, is a slight adjustment to allow the mold halves to close.

Things that I have observed:
1) The alignment pins are not loose so it is very unlikely the pins have moved...more likely the halves have warped.
2) The steel of the pins is fairly soft, so I have no interest in using a standard pin punch to try to set one deeper.
3) Attempting to set either the male or female side with a pin punch and a hammer would be risky inasmuch as there is no way to control how much the pin would move.
4) Neither the male or female side "fits" the flat surface of a standard pin punch...the male side has a "tit", the female side is hollow and has a slight bevel from outside to inside.
5) There is nothing on the mold faces that are causing them not to close.
6) Please do not suggest sending the mold back to Lee...I have had them refurbish several molds and I prefer to attempt a "fix" before I do that...this is not my first rodeo, I have been casting since the early 1960's.

So, any suggestions on how to set the pins a little deeper without bashing them with a punch...something I may have not anticipated? Note: I do not have a lathe so making pin punches to fit the pins is not an option.

[Camper64]

Would a bench vise or C-clamp that you can control how much pressure you apply for seating deeper work?

[poppy42]

First off I would place each face of the mold on a known, flat surface. Such as a drill press table, milling machine table, or something that you know is flat. I would then checked for abnormalities on each face of the mold. More than likely you’re going to find an area around the pins that is no longer Flat. Over time as the mold is closed and the pin touches the female side of the mold causing ridges. It doesn’t have to be much. I had a Lyman mold that I had to remove the pins and do both sides. Depends on lineman moles are easy I cannot speak for Lee moles as I have never had to remove them. I would not look forward to removing the pins from an aluminum mold so hopefully you can find an area that doesn’t require trying to remove and replace the pins. If you find the area stone it with a fine stone (home)very lightly until it’s flat and Polish it with some ultra fine sandpaper or emery cloth. I’ve had the problem on Lyman and Lee molds ( cause that’s all I got) And successfully fix the problem. Aluminum can be stoned haunted polish to remove imperfections you just got a remember it’s a lot softer than steel and if you go to much then you going to change diameter of the bullet . I hope this helps good luck
Sorry for any typos but my **** autocorrect keeps changing words faster than correct them

[RogerDat]

I had that problem on a Lyman. Very small rat tail file (round tapered) to bevel the edge of the holes and a new flat sharpening stone to clean up the holes the pins go into resolved it. One hole had a very slight ridge and the other hole had some metal pushed into the hole that kept the pin from going all the way down.

An experienced fellows first thought when I asked was to deal with the pins, a job he pointed out could be difficult. Almost as an after thought he suggested I look to the holes first since they are easier than the pins to deal with. Could find any engineers blue around so I just used a marker in the hole and on the pin and was able to see the rub points.

[dahermit]

Would a bench vise or C-clamp that you can control how much pressure you apply for seating deeper work?

Logically, that would have more control over how much the pins were set further, but does not address how to keep from distorting the guide pins...especially the male one.

[dahermit]

I had that problem on a Lyman. Very small rat tail file (round tapered) to bevel the edge of the holes and a new flat sharpening stone to clean up the holes the pins go into resolved it. One hole had a very slight ridge and the other hole had some metal pushed into the hole that kept the pin from going all the way down.

Or, instead of a small round tapered file, a center drill, or similar.

An experienced fellows first thought when I asked was to deal with the pins, a job he pointed out could be difficult. Almost as an after thought he suggested I look to the holes first since they are easier than the pins to deal with. Could find any engineers blue around so I just used a marker in the hole and on the pin and was able to see the rub points.

"Holes first" seems like a good idea. And, I do have "engineers blue" [sic, "layout dye"], to find the rub points. Thanks for the suggestions.