Lapping Mold?

[EMC45]

I have a Lee 160 gr. .309 mold that drops 'em at .310. I size for the .308 at .309. I want to load the same bullet in my Mosin, but it slugs at .312. Here is my question, can I lap with JB Bore Lap on the driving bands of this bullet in the mold block to about .314-.315? I was going to afix the lapping slug to a screw and work it in the mold. I would then tumble lube and shoot. What does everyone think?

[trickyasafox]

look up how to beagle a mold in the castpics section- it'll show you how to get that extra diameter without lapping the mold- might be worth a shot before you try permanant modification

[Scrounger]

I have a Lee 160 gr. .309 mold that drops 'em at .310. I size for the .308 at .309. I want to load the same bullet in my Mosin, but it slugs at .312. Here is my question, can I lap with JB Bore Lap on the driving bands of this bullet in the mold block to about .314-.315? I was going to afix the lapping slug to a screw and work it in the mold. I would then tumble lube and shoot. What does everyone think?

Man, Lee molds are so cheap, why not just buy one in the .312-.314 diameter?

[22cf45]

EMC45
I've done just about exactly what you are wanting to do in the same way except I used valve grinding compound. It worked just fine and the bullet shot well also. You have to cast one of the larger bullets every now and then as you progress to use for lapping to keep everything running as square and true as possible.
Phil

[VTDW]

EMC,

I read here how to to it but must not have saved the document I printed. I drilled into each lapping boolit before impregnating them with tungsten carbide then put a sheetmetal screw in the center of each base. Following directions read here I used liquid soap to lubricate each cavity before I lapped them as well as during. I chucked them up in a cordless drill. You will have to hold the mold halves tightly as with the lapping compound on the boolits of course the mold will not close all the way. I did this on a Lee 6-cavity and it worked beautifully. Just be patient and plan on having very clean hands and fingers when you finish.[smilie=1:

Dave

[Buckshot]

......................Man I'm sure with Scrounger on this one. Here's your chance to buy that 2C Lyman 314299 you've always been wanting :-). It's the bee's knee's in the M-N anyway.

...................Buckshot