bolt face pitted due to primer blowout?

Discussion in 'Gunsmithing' started by Wd40, Jun 21, 2010.

  1. Wd40

    Wd40 New Member

    Messages:
    3
    Joined:
    Jun 21, 2010
    I have a question regarding my Sendero chambered in 7mm ultra. I was using factory Remington ammo to break in the barrel. One of the factory rounds burnt through the side/back of the primer pitting the bolt face. My main concern is how this will effect accuracy? I would submit pics but I'm not sure how to?
     
  2. ewallace

    ewallace Well-Known Member

    Messages:
    991
    Joined:
    Mar 17, 2002

  3. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,311
    Joined:
    Jul 29, 2004
    It should not effect accuracy , But you need to find out why it blew the primer.

    This could just be a case of a bad primer pocket but it could also be a case of over pressure.
    And if it happens again the rifle should be checked out by a competent gun smith for an out of
    Spec, chamber. (Head space, neck Dia. , Throat length ETc.).

    The only other thing I can think of is that if your ammo was very hot (Left in the sun) this can
    cause over pressure.

    Try to figure out what caused it before it happens again.

    Be Safe !!!

    J E CUSTOM
     
  4. Wd40

    Wd40 New Member

    Messages:
    3
    Joined:
    Jun 21, 2010
    I was using Remington Factory ammo when this happened. Its was the first day out at the range. My concern main was if this would effect the accuracy of the gun. I was also planning on having this gun accurized and rebarreled in the future. Would the action still be ok for this? Since this happened I have put 70 rounds throught the gun with no problems. I just believe one bad factory round was the culprit.
     
  5. royinidaho

    royinidaho Writers Guild

    Messages:
    8,853
    Joined:
    Jan 20, 2004
    Deleted by me!

    I'm sitting here feeling kind of dumb and chewing a little crow.:rolleyes:
     
    Last edited: Jun 22, 2010
  6. phorwath

    phorwath Well-Known Member

    Messages:
    4,896
    Joined:
    Apr 4, 2005
    Pretty common to obtain a tad of erosion pitting from a loose primer, which will leave a ring the same diameter as the primer on the bolt face, or some gas erosion if the primer pierces at the firing pin hole.

    I'm surprised you haven't got some erosion markings on any of your bolts Roy? What with superglue employed to glue primers in place in loosened primer pockets. :) Pull out a magnifying glass and I wouldn't be surprised if you saw a ghost ring on the bolt face. Reloading cases with enlarged/loose primer pockets is a good way to get a little puff of gas against the bolt face.

    My guess is the description of pitting may be overkill. What I usually see is much more minor etching. Enough to remove the gunsmith's polish on the face of the bolt. And enough to feel the roughness with the point of a pin or needle. But no pitting exceeding what I would guess to be 0.001-0.002".

    It is possible to create pits, or even torch cut the face of a bolt. But that takes some real trying. Like the time a high school fella I knew was using Lee reloading volumetric powder measuring cups to measure powder charges, but didn't understand that the volumetric cups were paired to specific gun powders and cartridges. He started mixing and matching different powders (he was also reloading some pistol rounds) using the same Lee measuring cup and wondered one afternoon why his Rem 700 (.243 Win) Varmint-style rifle bullets wouldn't hit the railroad signs he was shooting at along the tracks. He mentioned several consecutive blue streaks of smoke traveling towards the targets but no hits. Then the bolt locked up tight on him. A gunsmith had to remove the barrel to get the bolt free from the action. The gunsmith told him his hand loads had welded the action to the receiver. Recommended the fella buy and read a reloading manual.

    Hard to say what pressures he was pushing, but he smoked several bullets before the rear of one of his cases let loose and the gases welded the action closed. A true wild-catter!

    But I agree this pitting/etching shouldn't be occurring with factory ammo in a factory rifle.
     
    Last edited: Jun 22, 2010
  7. royinidaho

    royinidaho Writers Guild

    Messages:
    8,853
    Joined:
    Jan 20, 2004
    Well I'll be a monkey's uncle!!!

    So that's why I couldn't get the ring off the bolt face.:rolleyes:

    Thanks phorwath.

    [​IMG]

    Anything else exposed in the pic that I should do something about?
     
  8. phorwath

    phorwath Well-Known Member

    Messages:
    4,896
    Joined:
    Apr 4, 2005
    There ya go! After reading about the superglue, I figured you'd have a ring around the firing pin. With loosened primer pockets, you'll get these even if the loads are safe pressure loads. I try to toss brass with loosened primer pockets in the effort to dispose of them preceding this burp of gas escaping the primer pocket.

    I use one of those Hart primer pocket saver tools. They'll give me another couple firings of the brass, but then I'll start to get a little leakage.

    If I'm using cheap brass I'll toss the cases plenty early to error on the safe side. If I'm using more expensive brass and have a lot of time in fire-forming, neck trimming, etc., I'll try to squeeze a few extra firings out of them.

    It's not good to keep on smoking that ring on the bolt face. Not the end of the world to have a case mildly burp every once in a while. But best to toss any brass that leak gasses there. Sometimes one can look around the edge of the primer with a magnifying glass and see that the brass crevice is blackened after firing. Or sometimes you'll see a little blackish discoloration on the case head or the face of the bolt. Generally means you've used the case once more than it should have been used. If I know I'm getting a relatively loose primer pocket, I'll use that brass at the range rather than in a hunting load, if I decide to use it another time. It's sort of a qualitative measure of primer seating force required to seat a primer that tells the tale of when it's time to toss the casing. But more of my rifles than not, have that ghost ring. All it takes is one primer burp. I'm such a miser, I keep trying to get another load out of my brass.

    I don't see anything wrong with your bolt, other than I can tell you've been super-gluing some primers in loosened primer pockets in the effort to pinch pennies! :D

    Some one may now come along and post that we're nuts for re-using cases to the point that we get one of these ghost rings. I say we're overly frugal. Now, that guy I knew in high school? He was nuts! Rambo... before Rambo. Best part of his story was how he described continuing to send blue smoke trails down at the signs until he couldn't open the bolt. Hard to say how many more rounds he'd have fired trying to reach that sign. Guess he got what he deserved - after all, he was going to vandalize those RR signs.
     
    Last edited: Jun 22, 2010
  9. ewallace

    ewallace Well-Known Member

    Messages:
    991
    Joined:
    Mar 17, 2002
    here are the pics of wd40 bolt
    [​IMG]

    and the case
    [​IMG]
     
  10. tnshooter111

    tnshooter111 Well-Known Member

    Messages:
    253
    Joined:
    Jun 18, 2010
    what did Remington say about this.
     
  11. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,311
    Joined:
    Jul 29, 2004

    That would be the thing to do(Have the bolt face squared at the same time it's re barreled.

    The Picture you posted shows that it is larger than normal and I would consider going
    ahead and re barreling in the near future. The reason it is not a good condition is that
    with the primer unsupported in some areas it can move and will more likely blow more primers.

    Roys bolt is the worst I have ever seen and with the ring all of the way around the cylinder
    part of the primer is unsupported and will surely move each time it's fired causing more
    gas erosion.(No disrespect to Roy who has probably forgot more than I know).

    I realize I am very fussy about these things but if it were mine I would replace the bolt or install
    a bushing to support the primer at the least.

    Primers are not designed to hold the pressure if unsupported only seal the case from escaping
    gasses.

    I'm not going to tell anyone not to use brass that the primer pocket is loose just because
    I won't. all I can do is recomend. Mainly because brass is cheep and machine work is not.

    Remington should fix your rifle because you were using Factory ammo in a factory chamber
    and obviously it was a case or load problem.

    Any primer blow out is not normal and should be researched to find the problem before
    continuing firing another round. It is a sign that something is wrong.

    This is just My opinion for what it's worth.

    J E CUSTOM
     
  12. phorwath

    phorwath Well-Known Member

    Messages:
    4,896
    Joined:
    Apr 4, 2005
    Something wrong with that rifle chamber headspace, perhaps? It looks as though the primer in that photo is actually set back further than the case head, rather than being smooth with the case head. Photo's a little fuzzy and hard to tell for sure. But if the face of the primer is protruding from the case head, then a knowledgeable gunsmith should examine your rifle.

    I would say Remington should fix it also, but I wouldn't hold my breath. They wouldn't fix a model 870 shotgun of mine that wouldn't eject Remington Peters shotgun shells. All they did was send me a bill with the shotgun, without fixing the ejector setback-to-chamber spacing.

    Anyhow, that's no ghost ring; the gas torched a wallow in that bolt face. "Pit" was the more appropriate term here. This is definitely abnormal, and I agree with JE. Better have someone examine the cause and resurface that bolt face.

    PS: JE is a gunsmith. I'm not. So I recommend heeding his advice on this one.
     
  13. royinidaho

    royinidaho Writers Guild

    Messages:
    8,853
    Joined:
    Jan 20, 2004
    This is becoming a great learning experience for me. Thanks wd40 for the original post.

    This kind of stuff is what this forum is all about!!!

    Yep, I know a lot, as do all of us. But I don't know what I don't know and I'm really good at not knowing what I don't know.:rolleyes:

    Experience it the greatest teacher as long as its someone else's experience!

    wd40's problem is a big one. That was some major damage! To the extent that it most likely deteriorated the rifle's performance. Shooting the rest of the shots sounds like something "I" would do.:rolleyes:

    For me it sounds like I need a shooting life style change. Its a lot of work to form the cases plus they aren't the least expensive cases on the shelf.

    I guess I'm going to have to settlefur a little less performance on the velocity end. And I HATE to SETTLEFUR!


    The poor ol' Allen Mag has been pushed very hard and long.

    Here's the evidence.

    [​IMG]
     
  14. Wd40

    Wd40 New Member

    Messages:
    3
    Joined:
    Jun 21, 2010
    Thanks for everyones input. I contacted Remington today. They seemed fairly interested in making this right. I'll keep posting. It will be interesting to see how Remington handles this situation. Thanks ewallace for the help with the pics.