primer pocket blow out.???

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by vino, Aug 21, 2014.

  1. vino

    vino Well-Known Member

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    Over the years I've had a few primer pocket blow outs .. I never go over the max load In my manuals.
    I usaly stay a full grain under . With that said I've had some blow out due to Lose primer pockets .?
    But could be wrong..
    It has happened alot in my ruger rifels and never has damage them just a little put of smoke and that's it..
    Whell it happened in 2 of my Remington 700 rifles one in 25-06 and one in 300win mag.
    One time in the 300 and 2 times in the 25-06. .
    Bolth of the bolt faces have a eroded hole in it from what I think is from the blow out..
    Is the bolt destroyed? ? Or do the bolts look like this normally?
     

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  2. MagnumManiac

    MagnumManiac Well-Known Member

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    That eroded spot will be there for the life of the rifle, it will pose no problem, other than when you decide to sell and any zealous buyer who looks at the bolt face will know you've run some hot handloads. Your bolt is not ruined.
    I wouldn't worry about it, but in future err on the milder side. Blown primers are always preceded by at least extractor/ejector marks on the brass.

    Cheers.
    gun)
     

  3. Barrelnut

    Barrelnut Well-Known Member

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    From what I've seen the erosion can get to be an issue as it allows the next primer to flow in the erosion and cause another blow out.

    Could be using a primer with a harder cup would help ( heard CCI is the hardest). Or if a magnum try a standard primer. Standards usually work good with 7MM, 300 WSM, etc.
     
  4. vino

    vino Well-Known Member

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    I'm a little confused about what or why. .
    The 2 in the 25-06 wad a once fired casing reloaded a full 3 grains under max with RL 22 and the primer did not fall in.?
    Are Remington bolt faces really that soft?.
     
  5. vino

    vino Well-Known Member

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    Was using winchester primers in bolth magnus in the 300?
    Have recently switched to federal 210 and 215 gm's.
     
  6. phorwath

    phorwath Well-Known Member

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    It's unrelated to the hardness or softness of the steel in the bolt. If the primer pocket enlarges in diameter enough that a new primer fits loosely, the seal between the edges of the primer and the primer pocket can leak high temperature and pressure gas and flame onto the bolt face and cut/etch away the bolt face. This can happen even with loads that don't exceed maximum pressure ratings for the cartridge with loose primer pockets.

    At higher (overloaded) pressures, it can happen with new brass on the first firing. Another issue that can increase the risk is excessive headspace, but I doubt that is your problem with the 300 Win Mag, since it headspaces off the belt rather than the shoulder, like the 25-06.

    The cutting you have is better than the etching caused by a pierced primer, which can enlarge the firing pin hole in the bolt face.

    I don't think you'll have any problems with continued use of your bolt, provided you don't keep leaking high pressure flame and gas around your primer pockets.

    You're shooting loads at excessive pressures in my opinion, because you're experiencing this with more than one rifle. Repeated shots fired at high enough pressures will expand the primer pocket until the primers seat with very little resistance, and then gas can escape and cut into the bolt face. Check your powder scale against another powder scale, or get some calibration weights to ensure your powder charges are correct.
     
  7. vino

    vino Well-Known Member

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    Thanks .. alot and good information. ..
    I just dont understand why it's happened hundreds of times in the 20 years on some of my ruger guns and there bolt faces look brand new.
    And with that gun i know it was loose primers. I thought I could squeeze one more reload out of the casing.
    And a little confused in why it's only done this to the Remington guns.?
    I own several brands of rifles and these 2 new model 700s have been nothing but headaches.
    I'm not trying to argue buy any means just trying to collect info and to prevent from future damage.
     
  8. Barrelnut

    Barrelnut Well-Known Member

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    I think you are right on soft steel in the bolt face. I have seen it on Savages too. Pacific Tool and Gauge makes hard steel bolt faces and bolts for Savage and Remington. This is probably one of the reasons why.
     
  9. vino

    vino Well-Known Member

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    I was thinking it was the gun because my 300 win is over 20 years old I bet it has easy 2k pluss rounds down the pipe.
    And I have tiikas.and savages.and winchester guns ..only 2 it's happened in is the Remington ones.
    Along with there bad trigger bad extractor and bedding issues..
    I thing those to 700s will need to find a new home.
     
  10. phorwath

    phorwath Well-Known Member

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    Just to clarify my prior statements. The steel of the bolt head is not responsible for the failure of the seal between the primer and the brass primer pocket.

    Now, after having experienced a failure of that seal, I'm sure that different grades of steel could be more, or less, resistant to etching/erosion/cutting upon exposure to the torch-like effect of escaping high pressure flame around the primer.
     
  11. jsthntn247

    jsthntn247 Well-Known Member

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    If you are seeing this on a particular rifle and your loads should not be hot, check the neck clearance in your chamber. Inefficient neck clearace will cause normall low pressure loads to spike quickly and blow primers.
     
  12. vino

    vino Well-Known Member

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    Thanks guys..
     
  13. MudRunner2005

    MudRunner2005 Well-Known Member

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    I had that happen with my .25-06 AI and a once-fired formed Winchester .25-06 brass. After swapping to forming out of .270 Win brass and seating them off the lands a little bit to help alleviate some of the pressure during ignition, I haven't had anymore issues.

    I can't seem tk find the thread with my pictures in it where it happened, so I'll post the pictures again.


    [​IMG]

    Left a perfect brass imprint in the bolt face...

    [​IMG]
     
  14. ksubuck

    ksubuck Well-Known Member

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