K&M Neck Turning Tool - 6.5mm Pilot too large (Is it just me?)

rustyinbend

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  • Dec 9, 2018
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    Anybody get the K&M Neck Turning tool with pilot for 6.5mm ... and find that the pilot is too big to fit your sized brass? Mine came today, and the only way to get the pilot to fit into the case mouth is to open it up to .2645 ... but I mandrel and shoot at .2625. The .2645 case mouth is way too big, causing projectiles to be really loose in the case neck. Am I doing something wrong? Did they send me the wrong pilot? Any advice out there before I call the manufacturer with this issue?

    It doesn't make sense for me to mandrel to an over-size case mouth in order to neck turn ... and then have to resize down and re-mandrel to get to my shooting case neck size. Any advice is appreciated ... I've never neck-turned before, but I have it all figured out, except for this "too big pilot" problem on this device.

     

    proff49

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    Feb 16, 2018
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    You have to use the k+m mandrel to size for the pilot. After turning you resize to your desired size for neck tension.
     

    Feniks Technologies

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    Neck turners based on pilots/mandrels have two mandrels. The first is the expander mandrel and the other is the turning mandrel.

    You use the expander mandrel first, then the turning mandrel for the actual cutting. Then you size things back to your desired interference fit.

    Using oversized mandrels accomplishes a few tasks. It ensures the neck is shaped as uniformly as possible. And even though the same inside diameter, not every cartridge uses the same interference fit. Depends on the individual loader and the application for the ammo. So oversized includes the entire array of interference fit.
     

    rustyinbend

    GySgt USMC 1976-1992
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  • Dec 9, 2018
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    Neck turners based on pilots/mandrels have two mandrels. The first is the expander mandrel and the other is the turning mandrel.

    You use the expander mandrel first, then the turning mandrel for the actual cutting. Then you size things back to your desired interference fit.

    Using oversized mandrels accomplishes a few tasks. It ensures the neck is shaped as uniformly as possible. And even though the same inside diameter, not every cartridge uses the same interference fit. Depends on the individual loader and the application for the ammo. So oversized includes the entire array of interference fit.
    Interesting ... I guess I see why it's necessary to have a standardized starting size via mandrel ... when you only have one size pilot. Never really thought about that. The .2645 mandrel on my 21st Century Mandrel Set is a perfect fit, so I'll use that. Using that mandrel to start, this gadget works perfectly. Just took a 6.5 Creedmoor case neck from 6/1000's of runout, to less than 2. Now I see why most advisers say to neck-turn new brass if required ... it's because sizing and mandreling multiple times to neck-turn is a PITA.

    Bottom line ... I get it. Thanks for the input.
     

    Cascade Hemi

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    Feb 9, 2019
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    An interference fit ensures concentricity with the brass ID. Use a little oil on the mandrel to prevent galling. I've found turning new brass and used brass to take the same process; size with die, size with "expander", turn.