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Primer question

Discussion in 'Ammunition & Reloading' started by IheartGUNS, May 9, 2012.

  1. IheartGUNS

    IheartGUNS WaCo Well-Known Member

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    I was reloading 45acp then switched over to doing 7.62x39. I forgot to empty out the Lpp and added Lrp to my press. Not knowing til after 50rnds later I had made this mistake. Whats the worst that can happen? I'm thinking that the primer won't have enough blast to ignite the powder and cause something like a squib load. FML
     
  2. speedtriple

    speedtriple Vancouver, Washington, United States Member

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    First off... I DON'T know for sure. But I will take a WAG that it will ignite the powder, and that the bullet will sail downrange at a bit under your estimated velocity. I will also guess that group size will not be as good.

    Test a few. See how they run. But my advice is worth just what you paid for it.
     
  3. Capn Jack

    Capn Jack Wet-Stern Washington Bronze Supporter Bronze Supporter

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    First thing, pistol primers are a little shorter than rifle primers, also the cup is a little
    thinner than a rifle primer. With that said, if you have been shooting Com Block Surplus
    without any problems, (they set their Berdan primers deeper) then there shouldn't be
    any problem setting them off.

    The problem arises when you compare chamber pressures...21,000 psi. for the .45 Auto
    against 45-50,000 psi. for the 7.62x39

    You are doubling the pressure against the thinner cup and asking for a burn through. The
    lest that would cost you is a new firing pin......YOUR CALL....:paranoid:

    Jack...:cool:
     
  4. speedtriple

    speedtriple Vancouver, Washington, United States Member

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    I would take Jack's advice... cancel mine!
     
  5. Throckmorton

    Throckmorton Florence,Ore ah gone Well-Known Member

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    I would not shoot them,I want all the fire and flame going AWAY from me.
     
  6. IheartGUNS

    IheartGUNS WaCo Well-Known Member

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    Waiting for deadshot to jump in...
     
    iusmc2002 and (deleted member) like this.
  7. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    Sorry, I go to bed early so I had to wait until this AM:cool:

    I can say that I've done this same thing. Capn Jack is correct that the primer material is thinner and the primer is a little "shorter". You are not the first to do this and just like all the others that have you can probably shoot them just fine. I would fire the first round and look at the primer. If there is no "piercing" where the gases are blowing out around the firing pin dent, or leaking around the edge of the primer, just shoot away and don't do that again. If there is a black hole where the firing pin dent used to be, then pull them down and use the correct primer next time. You are pretty much in the same situation as those who forget to use a magnum primer in a magnum pistol load.

    When the 7.62X39 round is fired, I assume in an AK or variant, the largest pressures will be developed while the bolt is still locked. When the bullet passes the gas port and starts to unlock the bolt, the pressure spike has passed. The bolt face will keep the primer in place so you don't need to "duck". Just remember to check the first fired case.