Reloading 101: Case Diagnostics Part II

Written by Sierra Bullets Ballistic Technician Duane Siercks

Once again I have a few cases that were brought in that have some issues. Careful case examination is one of the most important safety aspects of the reloading process. I try to bring this to light in these articles by helping to bring an understanding of the cause of some of the things we see on the cases. So read along and hopefully some light can be shed on something that will benefit you.

Click here to read Part I – Reloading 101: Case Diagnostics

1. Here we have a Lake City 7.62×51 (.308 Win.) case with two heavy marks/dents in the case body.

IMG_6417 IMG_6418 IMG_6419This one may be a bit of a mystery. It appears as if this case may have been caught in the action of a semi-auto rifle when the firearm jammed or the case failed to clear during the cycling process. I probably would not reload this case just to prevent any feeding problems. This also appeared to be a factory loaded round and I don’t really see any pressure issues or damage to the case.


2. This is a R-P .308 Winchester case with apparent problems from excess pressure.

IMG_6421IMG_6420If you will notice in the picture of the case rim, there are two pressure signs to notice. First, look at the primer. It is basically flattened to about the max of what could be considered safe. If this was the only pressure sign noted, I would probably be fine with this load, but would constantly keep an eye on it especially if I was going to use this load in warmer temperatures. This load could easily cross into the “excess pressure” realm very quickly. But, there is another sign of pressure that we cannot ignore. If you will notice, there is an ejector mark apparent that is located over the “R” of the R-P headstamp. This absolutely tells us that this load would not have been in the safe pressure range. If there were any of these rounds loaded, they should not be fired and should be dis-assembled. This case should not be reloaded. If you did reload you might experience a loose primer pocket due to the excess pressure this case has been subjected to and you could have a hard time discerning whether the next load ever produced another ejector mark or not. There were two marks on the case that I wasn’t sure about. They were located on the body of the case right below the shoulder and then directly above that on the neck of the case. It could possibly have happened when the case was extracted and it hit something on the bench or the ground surrounding. Whatever happened, it appeared to have been caused by a fairly sharp object.

3. Looking at this Lake City 5.56 case initially it would appear that there is nothing going on.

IMG_6422But…. upon very careful observation, two things become obvious. First,  the primer is about as flat as it needs to be. I wouldn’t have called “foul” on this alone, but I would not want to really see anymore pressure either. There was a very faint mark on the primer that may have been caused by foreign material being between the round and the bolt-face when the round was fired. This would not be of any real concern except to make sure that we get that object cleaned out. The real issue with this case is the bent rim. From the side it isn’t real noticeable, but if you hold it at an angle it clearly seen. This is an indication that there was an extraction issue. If this was fired in a semi-auto, it probably caused the firearm to cycle with excessive force. The extractor would have applied significant force and have bent this rim. This could be a warning of the round being a bit excessive in pressure. If this was fired in a bolt action, we are seeing a situation where there was excess pressure . Maybe causing the bolt to be hard to open and extra force needed to extract the round from the chamber. I would suggest backing off on the powder charge and reducing pressure.

4. This is a Winchester .308 Win. case that has a real issue.

IMG_6423IMG_6424This case has a very obvious incipient case head separation in the process of being a complete failure. This is most commonly caused by over-sizing the case causing there to be excess headspace on the case. After a few firings and subsequent re-sizing, this case is just about ready to come completely apart. Proper die adjustment is certainly a requirement here. Of course this case is not safe to reuse. Also note that the primer is excessively flattened.


5. This is a Federal .40 S&W case that has without doubt been fired in a firearm without a fully supported chamber.

IMG_6425This situation has been around for a good number of years and can be catastrophic. This case is severely weakened by this bulging. The chamber of the firearm is cut-away on the bottom side to accommodate the round to feed from the magazine. This leaves the case exposed by there not being any support from a chamber wall. There are dies made to help remove this bulging. But be very cautious. Because even though you might remove this “bulge,” you still have a weakened case. This sets up the possibility of this case being fired in another firearm that also has an unsupported chamber. This creates a risk of the case failing and causing severe damage to the firearm and shooter and also anyone close by. This can be a very dangerous situation. While many do reload these cases that have been bulged in the unsupported chambers, extreme caution should be used. Discretion, discretion, discretion……… If in doubt, throw it out!!!

6. Here we have an R-P .22-250 case that has died the death.

IMG_6428Everything looks fine with this case except…. the neck is split. This is a normal occurrence that you must watch for. It is caused by work hardening of the brass. Brass cases get harder with age and use. Brand new cases that are stored for a period of time can become hard enough that they will split like this case within one to two firings. I have had new factory loads do the same thing. Then as we resize and fire these cases repeatedly, they tend to get harder and harder. Eventually they will split. The life of the case can be extended by careful annealing practices. This is an issue that would need to be addressed in an article by itself. Of course this case is no longer usable.

In the classes that I teach, I try to use examples like this to let the students see what they should be looking for. As always, if we can assist you, whether you are new to reloading or very experienced, contact us here at Sierra Bullets by phone at 1-800-223-8799 or by email at

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46 Responses to Reloading 101: Case Diagnostics Part II

  1. Nice two articles on case problems. I like your saying cause I use it too… If in doubt, throw it out!!!


  2. Daniel Blake says:

    Great article! Thank you.


  3. Colin Lawson says:

    I have seen example #3 on numerous occasions- either just the bent rim, or the combination of the bent rim and flattened primer. The bent rim is common with AR rifles as most are over-gassed from the factory to ensure proper functioning even when filthy dirty. My own Sig-Sauer M400 did this right out of the box. I cured that by installing an adjustable gas tube and turned down the gas. The combination of the two is typical when someone uses NATO spec. ammo in an AR with a match or .223 chamber not cut for the 5.56×45 round, or if it’s used in an AR which does have the NATO-spec. chamber and it’s in need of a good cleaning.


    • Yes, the bent rims, while not exclusive to AR’s and semi-autos, are seldom seen in bolt actions or single-shots. Thanks for your comments and information Colin. – Duane Siercks, Ballistic Technician


  4. Pingback: Reloading 101: Case Diagnostics Part II | Rifleman III Journal

  5. Scott says:

    Thank you for the article. I hope you choose to present more of these articles in the future.


  6. firstriverbend says:

    One more in an excellent series of articles!!
    Thanks for sharing and all your effort to make this enjoyable to read and easy to understand. 🙂


  7. Robert Stubblefield says:

    Thanks for the schooling. Just getting back to reloading after 20 years. I will be loading a 375 RUM and by looking at loading data I will really need to pay attention. ( Always did but its been a while)


  8. randy says:

    i really appreciate your article but when it comes to the primers its really hard to see in your pictures on what u mean by flat primers other problems are easy to see im kinda new to reloading and very cautious thank you for your post


    • firstriverbend says:

      Randy, look at the Winchester .308 case and notice how the apparent dark ring formed between the primer and primer pocket is very narrow and almost no radius left to the primer, not a good thing. 😦
      Contrast that look with the Lake City 7.62 brass, which still shows a nice radius to the primer and a much wider dark ring left around the primer, showing the primer has not been extruded into the primer pocket opening as much.
      The radius of the shoulder of the primer is what I look at, needs to be fairly round still, not looking like someone “ironed” it into the primer pocket.
      Hope that helps a little bit. It is a fairly subtle detail one is looking at.


      • Thanks firstriverbend for the helpful comments.

        I believe that explains it all very well. I understand the pictures being a bit difficult to discern. We are thinking of how we might do them differently in the future. Thanks – Duane Siercks, Ballistic Technician


  9. Sam Vanderburg says:

    Wouldn’t a “Reloading Case Length/Headspace Guage” frpom Lyman help avoid the problm in example #4?


  10. firstriverbend says:

    Sam, yes and no.
    While a Headspace Gauge will help with setting things up to SAAMI specs, it will not prevent the problem shown if the chamber is long, which is common in many rifles, especially military semi-autos, even many, if not most military bolt firearms will have a long chamber.
    I have had a number of military bolt rifles which needed special attention to sizing if I wanted more than 2 or 3 reloading from my brass. However once I paid attention to the length of the chamber in the individual rifle, I would be able to reload a piece of brass 10-15 times using the same loading data that I used in over-sized brass which would show case separation issues.
    The fact this brass shows signs of being over pressured does not help either.
    For most of my bolt guns, I only neck size the case. They came out of my rifle, they will go back in. That being said, in a different rifle they may not chamber.
    Either way, always pay very close attention to overall case length!! If one has a necked size case which is too long and you jam it into the rifling, which is not hard with a bolt gun, you will see flat primers or worse.


  11. cl dickinson says:

    I received a couple thousand .223 commercial cases fire by the Dept of Prisons. Every one had a small dent, kind of like shown above.. I’ve reloaded them several times with no problem.. I was assuming it was automatic fire that caused the dent … (cant figure out what else would have done it… I’m sure there were multiple weapons fired… and 99% of the cases had this mark). Any thoughts?


    • firstriverbend says:

      As Brian mentions, it can be caused by bouncing off the ejection port. I have also seen rifles having the bolt hit the spent case on the rebound. Not sure if it is an under-gassed situations or an over-gassed situation.
      On our CETME it has happened too. CETME’s have a very fast bolt movement and I think the bolt rebounds off the buffer I added. It is one hundred percent reliable so far, so I do not care. Also, have had no problems reloading the cases, just not the prettiest looking reloaded at times, due to the striations on the brass from the fluted chamber.


    • CL – That is pretty common with the AR platform. Almost always I have seen at least a slight dent in the case that occurs during ejection. – Duane Siercks, Ballistic Technician


  12. Charlie Slaughter says:

    Excellent article, very well written with great explanation! Thanks


  13. Brian Deck says:

    I have seen #1 with factory rounds. I could see with slow motion video that the case was bouncing off the back of the ejection port, sending it in the 3oclock direction.


  14. SFC Charles Beck (Retired) says:

    A lot of good information (always looking for more information) One comment, the top casing you ID as a 308 is in fact a military 7.62. Same size as a 308 except the walls are thicker thus less room for powder. The little circle with the X in ids it as military.


    • I did identify it as a Lake City 7.62×51 (.308 Win.). I think that would say “military”. Sorry I did not spell that out. Thanks for bringing that to my attention. – Duane Siercks, Ballistic Technician


      • firstriverbend says:

        Does say “military” for me and most others. Lake City only makes brass with the L C head stamp to mil spec dimensions, unless they started running a brass line that is new to everyone. 🙂


  15. Preecha bhotiwihok says:

    You should put out a manual with the problems. Reloading manuals are incomplete. There
    Is a demand for accurate diagnosis and cause. Great job on this one – 101


  16. Jim Laviana says:

    I have been reloading for over 40 years and this article is the best illustrated example I’ve seen, thanks


  17. Ryan Burns says:

    SD 40 VE S&W 200 rounds had that bulge on it Gander Mountain brought out another one the sample case had a bulge on it they brought out another one and another one and another one they all had the bulge on it


    • Ryan – Be careful with any bulged cases. Reloading them does involve increased risks of case failures. This can be very dangerous and result in physical injury as well as damage to the firearm. – Duane Siercks, Ballistic Technician


  18. kim bro says:

    i just love learning new things to better my reloading thank you so much


  19. Sgt. Green Bullet says:

    Great article. The small details make a big difference, every bit of knowledge is another tool in your kit. Cheers, Sgt.

    Liked by 1 person

  20. Pingback: Reloading 101: Case Diagnostics | Sierra Bullets

  21. Great article and well written reference material. Thanks. I have a Vepr that dents cases like the Example 1 with the 7.62×51 case showing the marks on the side of the cases. As near as I can tell, the case hits the bolt handle or the end of the port during the ejection process. A friend has a Galil in 5.56 that dents the cases in similar fashion but in a little different spot farther forward. We have not reloaded any of them fearing the dent would weaken the side of the case.


    • Loran – The cases have probably not been weakened, but, depending on how severe the dent is, it may effect the powder charges by causing the case to have less capacity. This then would cause pressures to elevate. If the dent is very deep, you might have re-sizing issues also. – Duane Siercks, Ballistic Technician


  22. Ray Grigsby says:

    With AR’s and using a “small base” die for sizing I expect brass life to be reduced. Got a couple boxes of commercial reloads one time and had a couple case separations mid-case. Checked the rest of the 100 fired cases by running a wire down the inside of the case wall. There were about 30 that had developed a ring at the same point so I got rid of the whole batch😉


  23. Nick says:

    Have you ever seen one where a 7.62 case was marked towards the bottom of the shoulder with a ring around it, looking like there is a sharp shoulder in the chamber? These were fired in an AR-10 type rifle but with PSA receivers, Anderson bolt and barrel. A little high pressure signs from ejector marks on the head but not as severe as your examples. A few cases were hard to extract.


  24. Pingback: Reloading 101: Case Diagnostics Part II | Conservative Libertarian Outpost

  25. Jack Herndon says:

    I have 1911 that leaves the cases like #5 . Do you think that I should replace the barrel so I can have more case support.


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