Mold lapping?

[WM5L]

Got some new Lee molds last week and I tried to lap them to slick em up a little. bullets wouldnt fall out very good even after smoking them. The only way I know is to pour a bullet with the sprue plate open onto an old drill bit and then add some very fine lapping compound and turn the bullet in a drill real slow while in the mold. I can never get the drill bit straight and centered. There has got to be a better way. Pictures good as I need visual aid HA HA.....Jim

[BCall]

Open the sprue plate and pour it through an appropriate size nut, then turn the nut with a socket.

[WM5L]

If I have a 6 hole mold I need 6 right Or can I do all six of them with one nut/bullet ?

[JudgeBAC]

You can use one provided you do not wear away the boolit in doing so. Do a search on Leementing and you will find a wealth of information on the subject.

[Walter Laich]

I did the 'pour through the nut' method. Cast 3 at a time, nuts were too big to all fit on top at once. Did a total of 12 individual bullets just to be sure.

Used GoJo as it has pumice in it and more importantly was all I had around the house.

Did a good job.

On one Lee mold I had to come back and do it again but they now all drop out with just a light tap if any is needed at all.

[longbow]

On an aluminum mould I would go the pour through a nut method and turn by hand. It does not take long to remove aluminum. Using a drill is asking for trouble in my opinion.

I recently lapped a 6 cavity mould that had varying boolit diameters and block offset so slightly oval boolits. I started with the smallest cavity and cast a couple of boolits in it and used them in all cavities. Clean cast, measure and repeat as required. In the end all cavities were round and of almost the same size. I had to remove up to 0.003" from some and almost none from others.

Go slow, open and clean often, recast and measure often.

If you are just cleaning up you are really just removing burrs and polishing so very fine lapping compound is best.

Some good info here:

http://www.castpics.net/

Go to "Mould references" then "Mould lapping".

Also look at:

http://www.castpics.net/

"Leementing" by Buckshot.

Longbow

[WM5L]

WOW works like a champ! that was way easier that what I was trying...Thanks

[wallenba]

What I do is take an empty case that fits the boolit nose (38's center my 44 swc's), put the boolit in upside down. With them in a shellholder in a press with my Lee BHN tester I dimple the bottom for starting the bit. After drilling a hole then screw in a 3 inch drywall screw and chuck that in a cordless drill. Using toothpaste to smooth the cavity. A little 'wobble' won't hurt.

[kelbro]

What I do is take an empty case that fits the boolit nose (38's center my 44 swc's), put the boolit in upside down. With them in a shellholder in a press with my Lee BHN tester I dimple the bottom for starting the bit. After drilling a hole then screw in a 3 inch drywall screw and chuck that in a cordless drill. Using toothpaste to smooth the cavity. A little 'wobble' won't hurt.

Nice tip! I use my punch through the sprue hole to mark the center.

[2wheelDuke]

I poured the boolits as normal, but left them in the mold to cool. Then I cut the sprue, and used my drill press to drill pilots holes for the sheet metal screws.

I used toothpaste as an abrasive compound, and turned the hex head of the sheet metal screw with a spintight.

[Mal Paso]

I use the drill press and mold combination to get the hole straight. I also use the line created by the two mold halves to scribe a line, rotate the boolit 90 degrees and scribe again to get exact center. Sprue plate holes are not always centered.

[glen ring]

I have a Lyman mold for my 38-55 and it was dropping bullets too small.. I read somewhere on this forum about putting a screw in the base of a bullet and using valve grinding compound to coat the bullet. I did so, closed the mold and turned the bullet by using my drill. I just poured and sized a batch and it does work. The bullets are larger than before and it works great!!!! thank you!