300 Rum case runout

Discussion in 'Reloading' started by toklat04, Jul 30, 2008.

  1. toklat04

    toklat04 Member

    Jul 30, 2008
    I have noticed that a fired case has a neck runout of about.002 . when I resize with my RCBD dies i have about .005 neck runout. I would like to get the neck inline with the case body with minimal runout. Any suggestions. on dies or neck bushing . Not sure what I need.
    Last edited: Jul 30, 2008
  2. Derek M.

    Derek M. Well-Known Member

    Jul 12, 2004
    Turn the necks on a couple and see what that does. As I've mentioned in previous threads, you can also remove the expander, size a few and check them. If you have little to no runout on those sized brass, then your expander is likely a cause of some of the runout.

    I sent my sizer dies back to the manufacturer and had them hone the necks to where the OD of the sized brass is .002 less than a loaded round. No need for expander. No runout caused by die.