Lee molds

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Last Post 29 December 2008

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CB posted this 10 December 2008

I want to mill the top down on a 30 cal Lee mold, to eliminate the GC area of the mold. I need to understand how the sprue pay is bolted to the mold, and what thread is the bolt for th sprue plate.

Any help would be appreciated,

Jerry

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14 Comments

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jimkim posted this 10 December 2008

If your mould is made like mine, you will only be milling about 0.100” off the top. You should be able to go to the hardware store and match the bolt. More than likely you will be able to use the same bolts. I talked to Ranch Dog and he said that some people had reamed their moulds out to make them throw PB bullets. I suggest that a combination of the two would be best. You would ream out the base and mill the mould to form a good driving band(if that is the right word). I think I may have muddied the water a little. My apologies if I did. Jim

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303PV posted this 10 December 2008

The screw is the self-threading type. Just take it out and you will see what I mean.You can put it back after you machine the GC shank off.

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CB posted this 10 December 2008

Thanks for the suggestions and the info.

Jerry

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454PB posted this 11 December 2008

I would add that the screw is VERY tight. Use a phillips screwdriver that fits well (or a nut driver), clamp the mould in a vice, and put lots of down pressure on the screwdriver while you break it loose.

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CBA Member

JetMech posted this 11 December 2008

That's typical with a steel screw in aluminum that's been thru alot of heat expansion and contraction. A good technique is to put the screwdriver in the slot and give it a good tap or 2 with a hammer before trying to remove it.

The other trick to removing tight screws is to put a dab of valve grinding compound on the screwdriver tip. We used to also use Comet, but it's corrosive to aluminum. Would still work as long as you thouroghly clean the mould after. Using these techniques I've removed dozens if not hundreds of screws that defeated other mechanics.:coffee

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CB posted this 11 December 2008

I was thinking of putting iy in the deep freeze and then try to break the hold down screw loose. The mold will shrink the aluminun in all dimensions.

Jerry

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jimkim posted this 11 December 2008

Which Lee die is this? When I use mine I have to constantly tighten the screw. It can start out tight, gut once it gets hot it loosens up.

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CB posted this 11 December 2008

This is a Lee mold, I fat fingered the the key board and the M didn't come thru.

Try some Loctite 529 in the screw hole or even 592 (pricey)that should work for you.

Jerry

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JetMech posted this 11 December 2008

Jerry, I think you might want to try the opposite. If you cool the mould, the screw will be tighter. Look at Jim's experience. The rate of thermal expansion is greater with aluminum than steel. So heat that puppy up with a little Kroil around the screw, and for best effect, have your screwdriver frozen. Then when you put it to the screw, let it dwell 15 seconds, (that will cool and shrink the screw a little) tap the screwdriver handle with a brass hammer once or twice, and it will come right out.

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CB posted this 11 December 2008

I am not going to argue the point of thermal contraction, because I have done it and most people haven't. If you want try it go ahead, you will be surprised.

For holding a scrw in at the heats that we use, it is suggested that we use Loctite 499 to hold the screw in.

Merry Christmas,

Jerry

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CBA Member

JetMech posted this 11 December 2008

No argument, Jerry. You know what works for you. Good luck on your project.

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303PV posted this 12 December 2008

You can also put a set screw in the side of the mold. I have used M3 ,works OK.

Piet

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R D posted this 23 December 2008

Jerry; Sorry to be late in giving my ideas. But for what it's worth. I have used all of the recommendations and they work but I have found a twist that helps a lot for me. I made a wrench that fits in the chuck key hole of my drill press and goes around it about one third of the diameter. This I use as a handle and put my screwdriver bit in the chuck. I clamp the part with the screw in it in the vise and clamp it down tight to the table, fit the screw driver bit into the chuck, apply some valve grinding paste on it, fit it into the slot and turn with the wrench while holding down with the feed handle. I have had great results with this and by using a propane torch can add a little heat if it needs it. Be careful as you can twist one right into but this will keep everything straight and prevent slip outs if you have a drill press.

R D