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Thread: bump sizing

  1. #1

    bump sizing

    Hi, i was told this today just wondering if theres any truth to it, that not all full legnth sizing dies will bump the shoulder back,as i have a rcbs fl die?
    Regards Neil

  2. #2
    They should do, but very occasionally you get a minimum headspace chamber and slightly out of spec die. The only answer is to grind a few thou' off the bottom of the die or the top of the shellholder.

  3. #3
    well, ive been trying all day to get a couple of cases to chamber easily, there not too stiff but stiffer than the others, ive been experimenting with a couple of empties.

  4. #4
    Quote Originally Posted by drummerboy View Post
    well, ive been trying all day to get a couple of cases to chamber easily, there not too stiff but stiffer than the others, ive been experimenting with a couple of empties.
    Does your rifle cock on opening or cock on closing?

    What lube are you using on your cases? The best I've found is Imperial Resizing Wax, a little goes al ong way.

    If your cases are 0.001" longer than the chamber, you'll feel some resistence on closing the bolt. If they are 0.002" longer then you'll feel considerable resistence closing the bolt. If so, initially, remove the expander ball and lower your resizing die a touch. Ensure you bring the ram to its upmost position. This should solve the problem. Depending on your brass and expander ball and the lube you use, the expander ball can drag on the case and lengthen it by 0.001".

    -JMS

  5. #5
    Quote Originally Posted by JMS906 View Post
    Does your rifle cock on opening or cock on closing?

    What lube are you using on your cases? The best I've found is Imperial Resizing Wax, a little goes al ong way.

    If your cases are 0.001" longer than the chamber, you'll feel some resistence on closing the bolt. If they are 0.002" longer then you'll feel considerable resistence closing the bolt. If so, initially, remove the expander ball and lower your resizing die a touch. Ensure you bring the ram to its upmost position. This should solve the problem. Depending on your brass and expander ball and the lube you use, the expander ball can drag on the case and lengthen it by 0.001".

    -JMS
    Thanks for that JMS, I Will try this.

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