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Sig P220 - Double Firing Pin Strike

Discussion in 'Gunsmithing and Repairs' started by Werewolf, Dec 6, 2004.

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  1. Werewolf

    Werewolf Member

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    I reload .45ACP.

    My two loads are:

    1) 5.3gr HP38 under 230gr FMJ Fed 150 primer
    2) 8.5gr AA#5 under 230gr FMJ Fed 150 primer

    Both loads are well under SAAMI spec for the .45ACP according to published data.

    I shoot load 1 out of my Sig and load 2 out of my S&W 1911.

    When shooting load 1 out of the Sig I often find a small secondary dimple in the primer that intersects the firing pin dimple. In other words it kinda seems like the pin is hitting the primer twice. When shooting load 1 out of the 1911 no such double hit is happening.

    Question: I shoot Hornady .45ACP +P 230gr XTP's out of the Sig and don't get the apparent double strike. Is this a double strike in the Sig resulting from high pressure or is something else going on?

    I'm betting on something else since the load works fine in the 1911 and a +P load works fine in the Sig.

    What could be happening here?
     
  2. Jim K

    Jim K Member

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    Hi, Werewolf,

    A picture would help. I can think of several reasons, but prefer to wait until I can see a picture. Have you modified the gun in any way, like changing the hammer spring (mainspring) or the firing pin?

    Jim
     
  3. Werewolf

    Werewolf Member

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    Can't provide a picture.
    Don't have a digital camera.

    Imagine the firing pin dimple in the primer. Then imagine a smaller semi or quarter circle dimple at the edge of the main dimple and you've got what's happening.

    As an aside I posted the same message in the Handloading forum because the effect I mention is often a sign of over pressure. Two replies received both saying the problem is very common to Sigs.
     
  4. Frohickey

    Frohickey Member

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    Are you sure that its a small secondary firing pin strike?

    Or does it look as if its like a teardrop primer strike?

    Sigs, I have read, are supposed to keep their firing pin out a little longer to prevent debris from getting into the breechface.
     
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