FL sizing and collet sizing too?

Discussion in 'Ammunition & Reloading' started by gwtx, Sep 29, 2013.

  1. gwtx

    gwtx New Member

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    I have the mention somewhere on this forum about FL sizing without the expander, then neck sizing with a collet(lee?) die. Is there any significant advantage ? Gary

    sorry, I found the threads I was looking for.
     
    Last edited: Sep 29, 2013
  2. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    The expander will not go into the FL sized case. It is designed to be PULLED out of the case after sizing.
     

  3. mseric

    mseric New Member

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    Actually if you FL size without the expander the neck is also sized. You need to "open" the neck back up as most sizing dies squeeze the neck down way more than needed.

    You can open the neck back up a couple ways. Put the expander back in the die and expand the neck from the top down as opposed from the inside out as with normal sizing.

    You can use a Lee Collet die and just shove the mandrel into the case mouth, or you can go through the complete neck sizing motions and run the case into the collet die all the way.

    My favorite way to do this is to use a Lyman "M" die. It opens the neck back up nicely and you can apply a slight flare to the mouth if desired.

    The theory behind all of this is to keep bullet "run-out" to a minimum. Run-out can be caused by several things and the biggest cause is the expander button. When the expander is pulled back through the neck it can and does pull the neck off center just a little causing unwanted run-out. Expanding the neck from the top down helps eliminate these crooked necks.
     
  4. nitestalker

    nitestalker New Member

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    If you are that concerned about bullet correction to the axis of the bore? What about turning the neck wall to an even dimension. You can seat a bullet as you choose. The brass flow to the neck is uneven the bullet is firmly held off center unless the neck OD is corrected by turning. The expander pull back has some impact on neck flow. Most of the flow from above the web to the neck is a result of factors during firing. ;)
     
  5. gwtx

    gwtx New Member

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    Hey guys, thanks for the info. That's a lot deeper than I have gotten into reloading. Interesting, wish I could remember all the information I've gleaned out of the web in the last few years since I started reloading. The old memory drum has a leak :) I appreciate the sharing of knowledge on this forum. Thanks, Gary