Lyman M die 223 rem

Discussion in 'Handloading and Reloading' started by KY DAN, Aug 3, 2022.

  1. KY DAN

    KY DAN Member

    Joined:
    Jan 10, 2019
    Messages:
    653
    Can I modify the expander in a full length sizer die only eject a spent primer and then use a m die to prep the neck in order to ensure the case body and case mouth remain concentric to each other?

    Basically resize the outside of case and them expand the mouth in 2 separate operations
     
  2. jebova2301

    jebova2301 Member

    Joined:
    Sep 4, 2013
    Messages:
    179
    As someone that has a Lyman m-die in 223, I'm not really getting what you're saying, here. The m-die doesn't do the full expansion(technically, neither does the expander ball, but let's ignore that for now). The idea of the m-die is basically just to flare the neck to make bullet seating easier, primarily with bullet feeders(at least that is how mine works, and I doubt they redesigned it in the last couple years). Realistically, I don't see any reason you couldn't just swap out an expander ball with a universal decapping pin(Lee dies would make this very easy), then use the m-die to flare the neck and let the bullet do the rest of the expanding. I wouldn't imagine it would be enough neck tension to crush shoulders or damage the bullet, but I can't say for certain(and don't feel like adjusting all the dies in my press to find out).

    Personally, I would just use a normal resizing die like normal, then the m-die. That is how I have been using mine, and haven't had significant enough issues with concentricity to cause any noticeable effect on performance.
     
  3. AJC1

    AJC1 Member

    Joined:
    Jan 14, 2020
    Messages:
    7,919
    Location:
    Memphis
    Yes when using an m die expanding happens in a second step after sizing, with expander ball removed. This is the same as any expanding with a mandrel or a two step like the M or the NOE expanders.
     
    GooseGestapo likes this.
  4. 243winxb

    243winxb Member

    Joined:
    Jul 7, 2004
    Messages:
    13,296
    Location:
    Hopewell Big Woods.
    The Redding S die can be used with & without the expander, & still decap. Redding_1.JPG

    The M die is for cast bullet seating.

    For jacketed bullets, many now use this
     
    Last edited: Aug 4, 2022
  5. jmorris

    jmorris Member

    Joined:
    Sep 30, 2005
    Messages:
    20,419
    Who’s die do you have?

    If you also have a pistol die set from the same manufacturer, you might check and see if you can swap out the expanding decap pin for one that doesn’t expand at all (straight walled decap pins don’t expand or they would get locked into the die).

    F47AC86C-25DA-48B6-B017-AF4046D8CEA4.jpeg
     
  6. jmorris

    jmorris Member

    Joined:
    Sep 30, 2005
    Messages:
    20,419
    That said, that won’t ensure to give you 0.000” run out.

    I think the best use of a run out fixture is to allow you to test a fired case, each step along the way, and see if and where error is introduced.

    IF it’s OK after firing but right out of the size die, has run out. The first thing I would do is to remove the decap/expander completely. IF it doesn’t induce run out at that point, you a have found your problem.

    Now, I would explore case lubes and application of them in the neck of the case and repeat until sized cases are not being yanked out of round.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice