Lapping a Lee FCD with Diamond compound.

[Thompsoncustom]

I have had some 400 grit equivalent diamond lapping compound for a little while now and have been wanting to open up my lee factory crimp die. For those of you that have opened one up do you think running a round through the die to size it and than coating it in lapping compound and turning it in a drill would be a good way to go?

[alfloyd]

I lapped out one of my FCD with diamond lapping paste. I used a brass barrel adjustable lap to do it with.
It worked very well and faster than you might think. Lap a little and check, then repeat if necessary.

Lafaun

[chboats]

Do you actually need the sizing ring in your die? I used a punch to knock it out of my 44 die. The sizing ring was sizing the boolit too small.
Carl

[Thompsoncustom]

Do you actually need the sizing ring in your die?

Yes. From most of my cast boolits I don't use the FCD at all but with some of my super heavy 9mm ammo like this one 160gr RN the base of the bullet pushes the case out to much so the round doesn't chamber smoothly.


Planning on opening the FCD up to just under the size of my chamber.

[DougGuy]

FWIW, from what I hear about those FCDs they are not all created equal! They make them out of leftover pieces of carbide and the size varies quite a bit. Out of 3-4 of them you may get one that don't need lapping.