High Primers

Discussion in 'The Ammo & Reloading Forum' started by 312shooter, Oct 20, 2008.

  1. 312shooter

    312shooter Active Member

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    Does anyone know if there is ANY calibers or scenarios in which primers above flush are normal? I think I'm being fed some BS by a local guy on some reloading techniques as these "high primers" on 9mm sound dangerous as hell to me. I ALWAYS check primers for below flush I just wanted to consult the gurus on this story. Thanks guys!
  2. Gene Seward

    Gene Seward Member

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    Never heard of such a thing around these woods. LOL Sounds dangerous, and like you would have feed problems. It is amazing what BS is out there. I myself try to get them as flush as possible.
  3. Terry_P

    Terry_P New Member

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    Seat them flush as high primers can be a real issue. I've seen double BBL's double up because of a high primer. In a semi auto I think they call it a slam fire??
  4. LDBennett

    LDBennett Well-Known Member

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    NO reloading manual EVER suggests anything for primer height other than below flush. Flush is not even good enough.

    The primer has a small anvil inside it with legs that are designed to sit against the bottom of the primer pocket. When the firing pin strikes the back of the primer, it hits the anvil through the backside of the primer. If the primer is high then it has to first seat the anvils feet against the back of the primer pocket before any energy can be given to the primer compound. If it takes too much energy to seat the primer then there is not enough left for the priming compound to get ignited.

    Then there is the safety aspect. If the primer is high it can rest on the bolt face which can act as a big firing pin as the bolt slams closed. This can result in what is called a "slam fire" and in semi-auto guns it is a NO-NO. Any reloading source of information will advise that all primers MUST be seated below the face of the back of the cartridges or slam fires MAY occur.

    The only good source of reloading information is reloading manuals by large powder and bullet and reloading equipment manufacturers. Anything they print makes them liable so you can bet they researched and tested every recommendation in their manuals. The guy at the club or range who gives you a recommendation has no liabiltiy and can tell you anything he wants. He can take his own advice and suffer the consequences too. Don't be his guinea pig and take his advice. Stick to proven advice from an actual manufacture's reolading manual. BE SAFE!

    LDBennett
    Last edited: Oct 20, 2008
  5. Bindernut

    Bindernut Well-Known Member

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    Never heard of any cartridge using high primers as a "normal". Sounds dangerous and you're setting yourself up for slamfires...or even a discharge if you drop a round on the concrete beside you! I think the local know-it-all is full of wind on that one!

    With clean primer pockets and good brass the primer should be seated slightly below flush.
  6. artabr

    artabr New Member

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    Ditto to all of the above. Bindernut is dead on.
    You don't want to even chamber a high primer. Let the slide go on that and you could easily have a slam fire.



    Art
  7. TranterUK

    TranterUK Guest

    High primers would be very dangerous indeed, with the potential for detonation of the cartridge 'before' it chambered, sending bits of brass all over. And the unlikely but not unknown chain detonation of the rounds in the magazine!
    Last edited by a moderator: Oct 21, 2008
  8. Shellback

    Shellback New Member

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    LD your posts are very informative, you are a asset to this forum thank you. Again you are right in the 10 spot on this one, in no way ever should a primer be seated in that manner.
    Tim
  9. Dirtypacman

    Dirtypacman New Member

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    I have never heard of anyone reloading that looks to get anything but a flush primer. I have never read or heard anything positive about a High Primer.
  10. LDBennett

    LDBennett Well-Known Member

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    Dirtypacman:

    Not flush but below flush, but by only a thousandth or two.... you can just feel that it is below flush with your finger. My Dillon is designed so it only installs them one way: correctly and below flush.

    LDBennett
  11. mrkirker

    mrkirker New Member

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    Loading a tube-type mag with 'high primer' ammo is a Recipe for Disaster! :eek: Don't even THINK of it!
  12. 312shooter

    312shooter Active Member

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    Thank guys, I didn't have any intentions in doing so as I have never seen data that suggested this was a good move. I was interested to know if there was such a theory in our universe of reloading.
  13. Dirtypacman

    Dirtypacman New Member

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    Thanks LD - i also use a dillon and try to assure that is how they come out. I have had high primers cause problems before so I appreciate the clarification.
  14. bobkk

    bobkk Member

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    Bought a Ruger 44 carbine years ago. Well known manual said to use
    rifle primers if you were going to shoot them in a rifle. That didn't
    work they wouldn't seat flush. Glad I caught that on the first case.
    Primer pocket"s on pistol cases aren't as deep as rifle pockets.
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