Dents on shoulders of rifle brass

Discussion in 'Rifle Country' started by 50of4064, Sep 17, 2022.

  1. 50of4064

    50of4064 Member

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    A friend showed me some unusual brass that he shot from his Ruger bolt, in 300 WM....various head stamps, all factory new, no reloads..what was unusual was that of the three different head stamps fired, two had dents along the shoulders of the cases, in various degrees and spacing and the third head stamp showed no such markings at all. (The reason I am not denoting the manufacturers is to make this more of a blind test, so to speak, if that is even possible..)
    So my question is what causes these dents to accur? Checked for carbon or debris...none..if there was, then the dents would possibly be repeated...these seemed random and varied..
    I WISH I TOOK PHOTOS. I did not...
    Has anyone ever had anything like this happen ?
    Could use some help here.
    Thank you all ahead of time..
     
  2. Robert

    Robert Administrator Staff Member

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    Generally dents in the shoulder happen during the loading process due to extra case lube. At least that's been my experience while hand loading.
     
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  3. Mk-211

    Mk-211 Member

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  4. Walkalong

    Walkalong Moderator Staff Member

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    Fired cases? Newly sized cases?
     
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  5. conan32120

    conan32120 Member

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    maybe to much oil in the chamber and burned off by third type of ammo?
     
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  6. N555

    N555 Member

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    I think 300blackout dents the shoulder or case mouth when they are way over gassed. Like yiu take a gun setup to shoot subs and you shoot full power super sonic ammo.
     
  7. Demi-human
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    How large? Or small?
    Concentric? Axial?
    Soft edged dents, like lube or pressure? Or hard edged like dirt, brass shavings, or powder kernels?
    Any associated scratches fore or aft?
    Where on the shoulder were the dents? The face or right on the angle?
    Was there any associated carbon on the neck or shoulder area?
    Were the reports and recoil the same?
    What does the remaining ammunition look like?
    -Are they all the same COAL?
    -Are all bullet weights and shapes similar?

    Just imagine my questions if these were handloads…;)
    We need a bit more to go on than “random dent”.:D

    Hmm…How vigorously does his Ruger eject cases?
    Perhaps the damage is done after firing. Maybe cut a coil or two from the ejector? (I don’t know if that’s how Rugers work.:oops:)
     
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  8. Pat Riot
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    Pat Riot Contributing Member

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    Are the rounds hitting a scope mount or scope upon ejection?
     
  9. conan32120

    conan32120 Member

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    with the op saying new factory brass, not reloads and a bolt gun besides, one has to be led to believe that the chamber itself had to be contaminated somehow as the new brass would fireform to match the chamber. If the dents are smooth I would believe the contaminant to be fluid in nature, if the edges more sharply defined, irregular or "scratchy" I would believe a more solid contaminant such as the previously mentioned shavings or powder residue
     
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  10. lightman

    lightman Member

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    It could be several things. Maybe your friend has a foreign object in the chamber. As mentioned, possibly oil or even a spec of some kind of trash. I would start by cleaning the chamber.

    Many of the pictures posted in the links by Mk211 in post #3 look like ejection damage to me.
     
  11. 50of4064

    50of4064 Member

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    Fired factory new ammo.
     
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  12. 50of4064

    50of4064 Member

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    I posed that same theory to him, and he said that he cleaned the rifle that morning...and shot the ammo...what I did not nail down was the order of the different headstamps..ie..was the non dented the first or the last to be fired...but he did say he looked at the chamber for debri and found non..
     
  13. Varminterror

    Varminterror Member

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    Who in their right mind is slamming a bolt closed hard enough to dent brass? I’m a pretty big guy and run my bolts hard, and I certainly haven’t ever been able to close a bolt hard enough to dent the shoulder on a 300wm - bolts simply refuse to close. And if a guy IS slamming a bolt that hard, there wouldn’t be any mystery as to when, why, and how the shoulders were getting dented.

    It also won’t happen due to excessive oil in the chamber - lube will move readily away from the pressure of the case against the chamber, especially in a 300wm. We see guys even dipping loaded rounds in greases to lubricate shoulders - massive amounts of lube - and they still don’t dent shoulders.
     
  14. 50of4064

    50of4064 Member

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    To be honest, the dents looked to be hydraulic, like you expressed...but never in all my years have I seen it so pervasive, there would have to be an oiler port...
     
    Last edited: Sep 18, 2022
  15. Picher

    Picher Member

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    Recently, I got carried
    I just dented a bunch this past week, sizing a bunch of older cases, I lubed them a bit too much and dended several shoulders. I'd never done that before, in over 50 years of handloading, but was in a hurry and just making some varmint .223 ammo with a bunch of older cases. They should shoot fine for closer-range varmint hunting.
     
  16. 50of4064

    50of4064 Member

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    I am on board with your assessment and I am attempting to get some photos, and additional info..
     
  17. 50of4064

    50of4064 Member

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    These dents are more reminiscent of shoulder dents you would get when you hand load.
     
  18. 50of4064

    50of4064 Member

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    I am attempting to gather some photos of the cases, head stamps, number of rounds shot and the order of rounds were shot...if I can acquire those bits, I think with your help, we can start to answer what caused this..
     
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  19. 50of4064

    50of4064 Member

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    Hey there , I'm back and I have some pictures...and some details to fix.
    First. He shot two rifles that day a 300 WM and a 6.5 Creedmoor.
    Second. He does not recall which ammo he shot first, the Horniday or the Aguila...both being factory.
    Third. He did clean and oil the rifle before shooting that day.
    Forth. The images you see are the 6.5 Creedmoor brass that has been reloaded in these images 1153.jpeg ...but the dents are from the day that they were shot factory new.
    Fifth. Only the Honiday brass showed any dents, the Aguila brass showed no denting. Not knowing the brass that was shot first does not help.
    And yes, the denting looks to be hydrolic in nature to me, just as one might get if one were to apply to much case lube when reloading...but why on so many cases...we are talking about 10 cases shot in session, one could argue that by after a few rounds the oil should be dissipated and if not by then, when? That would be an afull lot of oil it would seem to me. They also look uniform, don't they? Or is it just me..so debris?
     
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  20. benEzra

    benEzra Moderator Emeritus

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    Is it possible that the brass of the original factory ammo was dented from the factory, and just not noticed until after they were fired the first time?
     
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  21. Demi-human
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    Those definitely look like lube dents.
    But how on earth did 55,000lbs of pressure not take them back out?:confused:

    I’ve seen low powered ammunition do weird things to brass, but that was reloaded, not factory.

    Evidently they sized fine and are holding a bullet.
    How is the concentricity? Maybe the brass has a thick side where the dent is? I’d want to cut one up.

    Very strange. Keeps life interesting!:)
     
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  22. David Hoback

    David Hoback member

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    That’s what I was thinking. If it’s just those three, and doesn’t happen again, they were likely there. Seen messed up factory loads before.
     
  23. 50of4064

    50of4064 Member

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    Demi...I will pass that thought on to my friend...I agree , if they were there from the factory, the case would certainly be fireformed to the chamber, along with any witnesses marks, So the opposite would be true also...if there were debris or oils in the chamber...
     
    Last edited: Sep 25, 2022
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  24. 50of4064

    50of4064 Member

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    David, it had affected 10+ Horniday brass that day, he does not recall which brass he shot first, the Horniday or the Aquila..he did mention that all the dents were on the Horniday brass and not on the Aguila brass...I suppose he did not inspect his brass as he was shooting each round...I was not there...strange stuff...
     
  25. Demi-human
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    Yup. I follow.:thumbup:

    All pretty mysterious, but in the end, everything works out okay. Must just be one of those things.:)
    I’d be racking my brain, too. Especially if it were a fellow shooter and not just myself.

    At least the Aguila came out fine, so it’s just a manufacturing defect in the ammunition, not a rifle problem or anything.

    I’d be interested if the dent was still there after a second firing of now being handloaded. That is serious force to resist.
     
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