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Primer thickness different?

Discussion in 'Handloading and Reloading' started by FieroCDSP, Apr 14, 2007.

  1. FieroCDSP

    FieroCDSP Well-Known Member

    Hi, y'all. I picked up a bunch of brass online, and while priming, I ran into an issue. Many of the pockets on the Winchester brass were too shallow for the CCI 500 primers I use. This is likely caused by the case having been reloaded with a max-load before (I might not have gotten them all separated from the factory), but I was wondering if there is a difference in the thickness (or height) of different primers. The brass itself seems okay, just the CCI primers aren't sinking in deep enough to ensure against a slam-fire. At least not enough for my tastes. I had to live de-prime a few while sweating bullets.
  2. sansone

    sansone Well-Known Member

    silly question maybe but is the primer pocket clean?
  3. FieroCDSP

    FieroCDSP Well-Known Member

    Yeah. I like to process before feeding them into the loadmaster. I'm glad I hand primed a few before going full-auto, because I would have crunched them and jammed things up.
  4. Walkalong

    Walkalong Moderator

    Max load won't hurt the pockets. Over max can enlarge them (in diameter) so they won't hold a primer. Strange.

    Are they hitting bottom and still sticking out or do they just need adjustment on your priming setup?
  5. FieroCDSP

    FieroCDSP Well-Known Member

    I was hand-priming with a Lee Auto-prime. I've had tough ones to seat completely (esp with Winchester) but these look like they are seating all the way down and still sticking up just enough to concern me. I black-listed the cases, but I was just curious if anyoen has actually done a measurement of the primers and found a difference.
  6. Walkalong

    Walkalong Moderator

    Never had a problem with 1000's of primers over many years. Do some measuring on the depth of the primer pockets on the offending brass. I suppose some could be to narrow at the bottom of the pocket as well as to shallow, but Winchester is usually very good brass.

    What caliber?
  7. FieroCDSP

    FieroCDSP Well-Known Member

    Okay. I'm getting an average of .116" on the brass in question. That's the depth at the side if the primer pocket. On some once-fired Win brass I fired last week, I have .122-24. I'm also pulling that number on some Remington brass I've fired 3-4 times. This is definitely enough to stick up the little bit I'm concerned about. Whether it's enough to cause a slam-fire, I'm not sure, but why chance it. 6/100" is quite a bit of difference.
  8. Walkalong

    Walkalong Moderator

    They make primer pocket uniformers which will cut the pocket to specs. This will take care of uneven sides and shallow depth. If there are not many cases like this it may not be worth it. Midway carries several types as well as reamers for crimp removal.

    You want one for uniforming, not cleaning.
  9. Steve C

    Steve C Well-Known Member

    If top of the primer is at or slightly below the plane of the base there's no possibility of a slam fire due to a high primer. Run a straight edge across the bottom of the case and if it doesn't hang up on the primer or otherwise show the primer above the base your are OK.
  10. Walkalong

    Walkalong Moderator

    I just measured 5 WSP primers. 2 were .1205, 2 were .1210, and 1 was .1215.

    I have been trying to find the spec for small pistol primers, but have not yet.

    .1210 sure rings a bell though. -- .1160 is not deep enough.

    I believe a uniformer will fix the problem. :)

    Addition: I measured some brand new Winchester .357 brass. The primer pockets were .1175 deep. My primers were right at .121 with the anvil sticking out of the cup about .014 and the cup measureing about .107

    I had to crush the primer a bit more than I would like to get them flush or below. I took my "Whitetail Design & Engineering" carbide uniformer and recut the primer pocket. It is now .123 deep. Good to go. I may recut all of this brass.

    Attached Files:

    Last edited: Apr 14, 2007
  11. FieroCDSP

    FieroCDSP Well-Known Member

    Thanks, folks. I'll look into a pocket uniformer. I hate to scrap any brass that is still usable.
  12. Bullet

    Bullet Well-Known Member

  13. Doug b

    Doug b Well-Known Member

    primer irregularities

    I ran into this issue with my hornady hand priming tool.The pins were walking out of the tool just enough to allow slop in the linkage causing a high primer,every once and awhile.I staked the pins and not had a prob since.Might not be your problem but worth checking.

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