Fins

[bishopgrandpa]

I bought an Ideal 457483 385 grain Round Nose from Fleabay for a great buy. (to great maybe) I cleaned it down and started casting. Every time I opened the mold the boolit fell right out without tapping the mold screw. All seemed great until I saw the fins running up one side and the other. I cooled down the mold and checked for lead on the faces. I checked the alignment pins and their holes. I sanded all edges inside and out. I even turned over the handles. Not sure why. Nothing helped. Do we have someone on the forum that has the knowledge and equipment to figure this out? It is a discontinued mold from long ago and I sure would like to see it work again.

[country gent]

Remove the blocks from the handles and seat together then with light pressure on them hold the seam to a bright light and look for gaps I look both from sprue plate side and bottom. If you see light its either an alignment problem with the pins or warped blocks.

If the fins are where the vent lines are then they may have been cut deeper and allowing them to fill.

If it started out good and didn't start until blocks heated up try a little cooler lead temp and or slower cadence to keep the blocks a little cooler so lead doesn't "flow" as easily.

[Dusty Bannister]

With the blocks off the handles, put the halves together and look for light between the blocks. That should guide the next step.

Measure the distance between the bottom of the grooves in the blocks. If it is close to .80" you need the large Lyman handles. If it is a little over .60" you need Lyman small handles. Hold the mold handles with the jaws parallel and see what the measurement is and that will tell you if you have the correct handles on the mold.

[bishopgrandpa]

I took off handles and held to light. Saw definite gap. Pushed out alignment pins and still saw same gap

[country gent]

Is the gap in the center or on the ends?

[too many things]

run blocks over a FINE stone till there is just clean metal . if you can get a dental pick and run the vent lines. if not run with a single edge razor blade

[bishopgrandpa]

Gap is in the center

[country gent]

Sounds like warped blocks. Could be heat related or the releasing of stress in the blocks. You have the easier one to work out. when the gaps are on the ends its harder since you have to physically maintain the trueness of the surface... This can be fixed and isn't super hard but care must be used in the process.
What you need to do is work slow and carefully watching the surfaces.
A piece of glass, truly flat plate, or best a surface plate known to be flat and fine wet dry paper in assortment of grits.
Remove pins and sprue plate all screws.
Clean blocks good.
mark one top edge A and the other B a marker works but dint rub it off
Place a sheet of Sand Paper on the flat surface I would start with 320-400 grit. A few small drops of oil or water on the paper.
Take block A with top pointing away from you lightly rub in a figure 8 pattern for 3-4 rotations. Rotate block so top points towards you and another 3-4 rotations. Wipe clean and check the polish lines patterns. Repeat this with block B and check it. mate the blocks together and check for light. You don't need to remove it all a small lone of original surface should be fine. by thin line of original surface around 1/8"-3/16" left showing. At the bottom of the cavity. When you get close switch to 600 grit and work slow and easy. You probably only need to remove .003-.005 but with sanding paper and flat surface that's a bit.
You may need to slightly deepen the vent lines at the outside of the blocks when done A small square and scribe work for this.
I would get it close and cast some then finish it up if needed. Also check some of the cast bullets with a micrometer across the parting lines for size then 90* for egg shape or out of round. Removing flattening the blocks should only remove the warp and out of round. If you go to far you may end up lapping back to round though.
A new clean flat stone will work but they arent always as flat as they should be and most are coarser than needed. I prefer the flat plate and paper best is a lapping table and compound.
BY marking the top surface of each block and rotating as you work them you maintain a flatter straighter surface. The water or oil helps keep the paper cutting clean and evenly. THe figure 8 pattern also helps maintain a flat even surface and works to give an evenly polished surface.

[Petander]

We Fins like ice hockey.

[Teemu]

We Fins like ice hockey.

[sigep1764]

Go Blues!!!

[jsizemore]

Page 13 of part 2 of the H&G owner's manual will explain how to adjust dowel pins:

http://castboolits.gunloads.com/show...d-Users-Manual

[Conditor22]

hold a straight edge across the mold faces to see if they are flat. If you knock in the pins then hold the molds flat on wet-dry sandpaper sitting on a piece of glass/smooth tile, sand a little to see where the paper is hitting. You might be able to get it working again. without seeing it I can't say for sure. YMMV

[Petander]

Does the gap change with temperature? Meaning,is it the same cold/hot?

[jughead76]

I have this same Lyman mold and I was having the exact same problem you were having. I closed the mold and held it up to a bright light and saw a very small sliver of light. Turns out one of the alignment pins was sticking out farther than the other one. I laid the mold, alignment pin down on a lead ingot and tapped on the back off the mold with a rubber mallet. I did this until the pin that was sticking out farther was pushed in far enough to look pretty even to the other one. When I put the mold blocks back together, the gap was gone and I haven’t had any more issues with fins on my bullets.

[John Boy]

Another option to eliminate light between 2 mold halves: put mold halves together in a padded vice and squeeze them hard