Question about decapping .40 cal brass

Discussion in 'Ammunition & Reloading' started by LMS_Tactical, Sep 30, 2010.

  1. LMS_Tactical

    LMS_Tactical New Member

    hello. I am in the process of decapping .40 cal brass and I seem to be having trouble. I have to cycle the press twice on 90% of the cases in order to get the old primer to pop out. I am new to this and perhaps I dont have the resizer seated propperly. I have adjusted it three times according to the nstructions and I am afraid that if i get it to tight, I will snap the pin. I am using a single stage RCBS. Any thoughts will be appreciated.
  2. hunter Joe

    hunter Joe New Member

    What brand brass are you using? By the way, welcome to the forum.

  3. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

    I have this happen more often with .40 brass than any other. I am not sure what the cause is. Make sure your sizing die is set so it nearly touches the shel holder. Set the die, size a case with out a primer in it. Adjust the decapping rod deep enough the pin lock nut (or shoulder on the new style die) just touches the inside baase of the case. Back the decapping rod 1-11/2 turns (or retract the rod about 1/16" on the newer dies)
  4. LMS_Tactical

    LMS_Tactical New Member

    American Eagle... federal.
  5. LMS_Tactical

    LMS_Tactical New Member

    Thank you for the advice. I will do as you suggest and let you know how that worked out. Much appreciated :)
  6. LMS_Tactical

    LMS_Tactical New Member

    P.S. Thank you for the warm welcome. I appreciate it. Looking around... it seems to be a great forum. I can't wait to get deeper into it.
  7. cpttango30

    cpttango30 New Member

    Exactly what I was going to say. Dang you Robo....
  8. noylj

    noylj Member

    Per Hornady:
    Before using your new dies, disassemble and carefully clean
    the inside surface of the sizing and seating dies (and the
    expander die if a three-die set.)
    Inspect all cartridge cases and discard those with cracks,
    splits and other visible defects. Wipe cases clean with a soft
    cloth to remove grit and other foreign matter which may
    scratch the die.
    To adjust the expander/decap assembly:
    1. Loosen the spindle lock.
    2. Adjust the spindle so approximately 3/16"
    of the decap pin is below the end of the die
    (Ed: insert empty case in shell holder/shellplate. Raise ram so case enters die. Wiggle the decapping stem if it doesn't enter the flash hole. Primer should pop out. If not, lower ram and turn the decapping stem in until primer is ejected. Raise ram and lock the decapping stem and the resizing die.)
    3. Tighten the spindle lock. If not tightened sufficiently, the spindle will
    back out the top of the die when deprimed, or it will pull out of the die
    when the ram is lowered. If the spindle is adjusted too high, the primer
    may not be expelled and a new primer cannot be seated.
    To adjust the full-length size die, follow these steps:
    1. Raise the press ram to highest position without camming over.
    2. Thread the full-length die into the press until the base touches the
    shell holder head.
    3. Tighten the lock ring against the press and tighten the set screw
    with the allen wrench.
    4. Adjust the expander/decap assembly.
    This applies to all normal sizing dies. I have heard that some people sharpeded the decapper pin tip to improve things. I would have expected to flatten the tip to improve things.
  9. Overkill0084

    Overkill0084 Active Member


    Being a newby myself, I figure the best way to avoid issues is to follow the instructions closely. Using the RCBS version of the above text, I've never had any issues decapping .40 S&W.
  10. Rick1967

    Rick1967 Well-Known Member

    I reload 40 S&W in large quantites. I have found that if I start out doing several hundred I will have to retighten the decapping pin. It will loosen up inside the die. I use RCBS dies and a RCBS press. If your pin is not tight enough it will do as you describe.
  11. noylj

    noylj Member


    LocTite Blue is your friend.
    I have never had that problem with RCBS dies, but I would think a drop of LokTite Blue would take case of it loosening.
    I think that all bolts should have Loctite or anti-seize applied. Durn things always decide to work loose at the worst possible time.
  12. at_liberty

    at_liberty New Member

    Examine removed primers (wearing gloves) to see if the decapping pin is piercing the primer cases. If it is, the primer body is stuck on the pin shaft and just gets drawn back to the primer pocket when the press ram retracts. I think that would indicate that the pin is hitting the primer with too much force. Slowing down to a press instead of slamming motion should help. It should also indicate that the pin needs to be blunted rather than sharpened.

    I have never had this problem with a Lee decapping pin but immediately experienced it when I bought a Hornady die for one of my calibers. All I have done so far is slow down to a "press" motion rather than a "ram" motion. It is easier on me too.