Neck Size for Neck Turning

[ej3rd]

Greetings,

I want to neck turn new and fired brass. None of my neck sizing devices (Wilson bushing neck die, Lee Collet die) will size the neck down small enough to fit tight on my Sinclair expander mandrel let alone the actual neck turning mandrel. My normal case sizing process and to get the desired neck tension is to use the Redding Body sizing die and the Lee Collet neck sizing die.

I'm guessing I need to use a regular full length sizing die, remove the decapping rod/expander ball assembly, size the whole case then use the expander mandrel to bring the neck back up to sizing diameter?

Thanks,

E. J.

 

[LHSmith]

If you can't expand new brass something is wrong. I don't neck turn fired brass.

 

[ej3rd]

I need to reduce the neck size to be smaller than the expander. That's my problem, I can't get the necks small enough.

 

[LHSmith]

A .24 cal expander should be snug fit in the neck of new .243, 6mm Rem., 6mmBR, or any other unaltered factory new .24 caliber brass. What are you starting with and what do you want to end up with?

 

[savagedasher]

Greetings,

I want to neck turn new and fired brass. None of my neck sizing devices (Wilson bushing neck die, Lee Collet die) will size the neck down small enough to fit tight on my Sinclair expander mandrel let alone the actual neck turning mandrel. My normal case sizing process and to get the desired neck tension is to use the Redding Body sizing die and the Lee Collet neck sizing die.

I'm guessing I need to use a regular full length sizing die, remove the decapping rod/expander ball assembly, size the whole case then use the expander mandrel to bring the neck back up to sizing diameter?

Thanks,

E. J.

Your last process is how I would do it. I feel you should size the brass first. Then make the internal size round the turn the out side. By sizing the brass you have only pushed the external inside.
Larry

 

[ej3rd]

I'm turning .223 brass. Initially I just wanted to clean up the outside of the necks. Brand new Lapua brass was a loose fit on the sinclair mandrel. I'm just not sure of the best way to reduce the neck diameter for the proper fit on the mandrel.

 

[LHSmith]

Mike the expander or turning mandrel. Measure the OD of the necks on the new brass. Was the box factory sealed? Have you neck turned brass before?

 

[Patch700]

I'm turning .223 brass. Initially I just wanted to clean up the outside of the necks. Brand new Lapua brass was a loose fit on the sinclair mandrel. I'm just not sure of the best way to reduce the neck diameter for the proper fit on the mandrel.

When you say brand new that tells me new and unfired.... having said that if it doesn't fit your mandrel I'd say you have a mandrel problem... time to dig out the micrometer.

 

[ej3rd]

Yes. Brand new Lapua brass from a factory sealed box. I guess it's possible a Sinclair mandrel is undersized. I would think that is a rare thing but it make sense to mic it. I'll check it out.

 

[LHSmith]

I'm thinking you have NT components for 20 cal (.204) and not .224

 

[artbosco]

I'm turning .223 brass. Initially I just wanted to clean up the outside of the necks. Brand new Lapua brass was a loose fit on the sinclair mandrel. I'm just not sure of the best way to reduce the neck diameter for the proper fit on the mandrel.

Call the manufacturer of your turning tools!

 

[gotcha]

I think LHSMITH & OUTDOORSMAN have the best advice. Beyond that you could reduce the size of your LCD's mandrel via hand polishing. But you REALLY need to check diameter of your expander with a Mic. before doing so.