Reloading 101: Case Diagnostics

Written by Sierra Bullets Ballistic Technician Duane Siercks

I was handed a small sample of 223 cases the other day and was asked if I could comment on some marks and appearances that had been noticed as they were sorting through the cases. I will share what was observed and give you what would seem to be a cause for them. These were from an unknown source, so I have no way of knowing what type of firearm they were fired in or if they were factory loaded or reloaded ammunition.

1.) Lake City unknown year. 

Case #1 was seen to have a very rounded shoulder and split. Upon first look it was obvious that this round had been a victim of excess pressure. The firearm (perhaps an AR?) was apparently not in full battery, or there was possibly a headspace issue also. While taking a closer look, the primer was very flat and the outside radius of the primer cup had been lost. High pressure! Then I also noticed that there was an ejector mark on the case rim. This is most certainly an incident of excessive pressure.  This case is ruined and should be discarded.  See photo below.

Case1Collage

Case 1: Left to right, bulge and split, flattened primer, and ejection marks.

2.) Lake City match 93 

Case #2 appears very normal. There was some question about marks seen on the primer. The primer is not overly flattened and is typical for a safe maximum load. There is a small amount of cratering seen here.

Case2

Case 2: Cratering around the firing pin hole.

This can be caused by a couple of situations. Cratering is often referred to as a sign of excess pressure. With safety in mind, this is probably something that should make one stop and really assess the situation. Being as there are no other signs of pressure seen with this case, I doubt that pressure was unsafe. That leads us to the next possibility. This can also be caused by the firing-pin hole in the bolt-face being a bit larger than the firing- pin, and allowing the primer to flow back into the firing-pin hole causing the crater seen here. This can happen even with less than max pressures, in fact it has been noted even at starting loads. Always question whether pressure is involved when you see a crater. In this situation, I lean toward a large firing-pin hole.  This case should be safe to reload.

3.) R-P .223 Remington   

Case #3 appears normal with one exception. There are two rings seen about one half inch below the base of the shoulder.

Case3A

Two rings about one half inch below the base of the case shoulder.

These rings are around the circumference of the case, one being quite pronounced, and the other being noticeably less. As we do not know the origin of the firearm in which this case was fired, it does seem apparent that the chamber of the firearm possibly had a slight defect. It could have been that the reamer was damaged during the cutting of this chamber. I would suggest that the chamber did have a couple of grooves that imprinted onto the case upon firing. This firearm, while maybe not dangerous should be looked at by a competent gunsmith.  In all likelihood, this case is still safe to use.

4.) R-P .223 Remington   

Case #4 has no signs of excess pressure. There is a bulge in the case just ahead of the case head that some might be alarmed by.

Case4bulge

Bulge in the case just ahead of the case head.

This bulge is more than likely caused by this case being fired in a firearm that had a chamber on the maximum side of S.A.A.M.I. specifications. There is actually no real issue with the case.  Note that the primer would indicate this load was relatively mild on pressure.

Case4Primer

The primer would indicate this load was relatively mild on pressure.

If this case was reloaded and used in the same firearm numerous times there might be a concern about case head separation. If you were going to use this case to load in an AR, be sure to completely full-length re-size to avoid chambering difficulties.  This case would be safe to reload. 

5.) Lake City Match 85 

Case #5 appears very much like case #4. The bulge is not as pronounced as on the R-P case, and if fired in the same gun, may simply be because the Lake City case is slightly heavier walled.

Case5

Case bulge.

The primer again shows that there was no excess pressure involved. This could probably be termed as “normal”.  This case would be safe to reload.

6.) R-P .223 Remington Case

Case #6 shows some rings around the circumference that are very light and hardly noticeable.

Case6_rings

Rings around the circumference of the case are very light and hardly noticeable.

This was fired in a different chamber than case #3, as the rings are in a different location and not as heavy. The primer looks good and there are no pressure issues with this case.  This case would be safe to reload.

Case6_Primer

The primer would indicate this load was normal.

It is very important to observe and inspect your cases before each reloading. After awhile it becomes second nature to notice the little things. Never get complacent as you become more familiar with the reloading process. If ever in doubt about a situation, call us at 1-800-223-8799.

Read more in Reloading 101: Case Diagnostics Part II

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57 Responses to Reloading 101: Case Diagnostics

  1. firstriverbend says:

    Great article, one of the best on case inspection I have ever read! Thanks.

    Like

    • Thank you. Glad to hear you enjoyed it.

      Like

      • firstriverbend says:

        You are welcome!
        I have been reloading since the early 70s and have read a large number of books, etc… over the years. However, this is by far one of the clearest articles explaining several possible reloading issues.
        When looking again at case one, it does present some interesting questions.
        One thing I think i am noticing in the photo, not the same as seeing in real life, is an odd ring just under your exacto knife tip, at the base of the shoulder, start of the case neck, it appears as though there is a small ring. Without seeing the case this could just be an anomaly in the photo. However, if it is not, it would appear to be a pressure ring created by the cartridge being partially out of battery or a very poorly reamed neck region in the chamber.
        If this is actually correct and it exist as evidence of an out of battery discharge, then you look to be having an extremely over pressure round!
        The reason I say this is because an out of battery discharge, while tough on the bolt, is going to be lower pressure due to the longer leade, increasing the distance of bullet travel before engaging the rifling, resulting in lower pressures.
        But this is a possible clue too! 🙂
        If the round was a reload and the bullet was a long one, like say the 90 grain 9290, seated out too far, where the bullet engaged the rifling before the bolt close all the way, it could account for all of the damage to the case presented. We are talking only a few thousands of an inch, but with a compressed charge of powder, which would not allow the bullet to move further into the case, holding the bolt just out of battery, you would end up with a ring at the neck, a spit neck, a very high pressure round, cratered primer and an extractor mark. At least this is where I would tend to go looking for problems when presented with this case.
        Just saying. 🙂

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  2. Cliff Morris says:

    That LC case with the bulge ahead of the extractor groove also looks a bit chewed up in the groove. Do you think it could have been fired in a SAW or other full auto weapon and experienced some of these issues because of that type weapon system?

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  3. Paul Bowsher says:

    Good info…thank you. Please see below

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  4. Mike Welles says:

    Thank you.

    Like

  5. ozzynator says:

    Is flat primers always caused by high pressure? I get alot of flattened primers even on very low powder charge, what could cause this? This is only in one gun, and in others the cases seem fine.

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    • firstriverbend says:

      I would check the leade on this firearm and look closely at the cartridge neck for contact.
      Could be a short chamber or short throat. Whatever the problem, something is not right about that firearm.

      Like

  6. You can experience flattened primers on low pressure loads also. This usually occurs when pressures are not high enough to expand the case enough to grip the chamber walls and the case is then driven back with sufficient force to cause the primer to flatten. Most of the time you will also see powder residue around the case neck and shoulder along with this. – Duane Siercks, Ballistic Technician

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    • firstriverbend says:

      Had another thought on the flatten primer, with low powder charge, could be the powder.
      Without knowing which cartridge and which powder bullet combination, one is forced into many assumptions.
      If this is a small charge of say H110, in a large case, you can have very high pressures from a low powder charge.
      This is an interesting problem/question and one that would be nice to know more about.

      Like

  7. Supersparks says:

    Great read. Very informative. I have a firearm that has a rough chamber on the shoulder as if a chip hung on the reamer or the lathe was turned off while the reamer was still engauged. I have reloaded the same cartridges 5 times without problems but I pay close attention before cleaning them for carbon tracks on the shoulder for cracks or separation.

    Thank you for sharing.
    C

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  8. Eugene Hollenbeck says:

    I would love to see what you think of factory ammo I fired in my .300 WSM. Missed a deer twice (had sighted in my scope and was all fine just days before this), the shots went high by three feet or better at 100 yards. Picked up my brass and both shells had three splits running along the length of the case. Flat primers in both. Crazy high pressure? Ammo was Federal, last box I’ll ever buy from them!

    Like

    • From what you describe, it would sound like high pressure. There are a lot of variables that can certainly be important information in a situation such as this. Contacting Federal with the lot number on that box of ammo would be my first suggestion. Thanks – Duane Siercks, Ballistic Technician

      Like

  9. Jm du plooy says:

    Reloading data for 22-250 howa

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  10. tiredcarpenter says:

    About case #1, Could this Lake City be a factory 5.56 fired in a 223 chamber? Excellent article and top notch trouble shooting. Well done!

    Like

    • That is a possibility, but again we do not know the source or origin of these cases. Thanks, Duane Siercks, Ballistic Technician

      Like

    • Lee Trunnell says:

      is the 223 different from the 5.56? i thought they were the same, just one is metric designation and the other is numerical designation.

      Like

      • firstriverbend says:

        While they share similar dimensions, and can be interchanged in the firearm, the 5.56 is loaded to a higher pressure, with resultant faster velocity.
        Because of the higher pressure of the 5.56 do not use them in a rifle marked for .223!
        You can use both .223 and 5.56 in rifles marked dual caliber or 5.56 chambering, but do not use 5.56 in rifles only marked .223.
        It is important to be aware of the markings on the firearm and use the appropriate ammunition for both yours and the firearms well being.

        Read this article for an older, but good explanation of the differences and potential problems. http://www.thegunzone.com/556v223.html

        Like

      • The case dimensions are the same. Factory 5.56 ammo can produce a bit higher pressure than factory 223 ammo. Firearms labeled as 5.56 usually have a longer throat and almost always a faster twist rate. 223 factory guns may or may not have the longer throat and/or faster twist. Thanks, Duane Siercks, Ballistic Technician

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  11. Joe Marek says:

    Don’t forget to mention the tip on ‘ how to use a straighten paper clip or stiff wire trick ‘ for inside the case scratching to detect any case web separation. I learned it from you guys at Sierra Bullets long ago. I used that tip all the time during my fired case perpetration just to check my cases. I toss those that feel smooth inside!

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  12. Erik Jensen says:

    Can you resize a 308 case into a 243 case, like you can a 300 blackout from a 223 case.

    Like

    • Yes, that is certainly possible. It isn’t necessarily done in one pass though. That is a drastic change from .308 to .243. You would probably have less troubles if you would run the 308’s through a mid-range die like a 7mm-08 or 260 die and then through the 243. Or for best results get a case forming set from RCBS. Thanks, Duane Siercks, Ballistic Technician

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      • DAVID C LOOMIS says:

        When one goes from .30 to .243 the neck gets thicker. Every time that case is shot and reloaded the neck gets thicker before long when the cartridge is chambered the bullet is held to tightly in the case and a pressure problem develops. Turn down those necks!!!

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  13. John Koroly says:

    I have a Remington 700 30/06 that even with a variety of factory ammo the primers appear flattened. Some time back I had fired some reloads my father in law had given me where the primers were both flattened and cratered. He assured me must be something wrong with the gun so I took it to a gunsmith and had it head spaced and chamber checked. He said gun was fine, case appeared to be over pressure load. So is any primer flattening without cratering acceptable?

    Like

    • firstriverbend says:

      One thing you might want to have checked is the bore/rifling diameter. Not all barrels are bored/rifled to the same diameter. Even the specs can be changed from year to year.
      While the chamber and head space can all be good, it the bore is on the bottom of the diameter range, it can cause higher pressures. An example would be Ruger versus Smith & Wesson in .44 magnum. My Super Blackhawk was .429, the Smith is .427. Same round in the Smith is right on the edge, while very good in the Ruger.
      This is just one of the reasons for working up a load, and never trust a reload for a different firearm in your own! There are a number of factors that vary between firearms. As you have discovered, if they all lean one direction, it can show up as too much pressure. Might consider taking it to a gunsmith able to measure the inside of the barrel. I would also check the leade of the barrel. I have seen some problems related to it being on the short side for the cartridge.
      I have a 5.56 with a polygon bore, it shoots great and the bullet come out faster over my chronograph, but it also tends to flatten the primers more than I like if I am not careful. Seems to be a bit more temperature sensitive than our other firearms. Does not show excessive pressure signs exactly, just shows more pressure than some other barrels of 5.56 with the same powder charge, primer, brass combo. It is new to us, so still a work in progress.

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  14. leo brosche says:

    I have a 338-06 improved with a shorter neck ( 338 hawk or scovill) loaded with 58 gr rl15 and have used same load for ten years. recently case necks have been splitting part way from mouth to neck. Is this a pressure problem or a case neck hardening problem?

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  15. Adrian says:

    For case 3, a possible explanation is the use of a deburring tool such as the lee debur/chamfer version. I ended up with the same thing on my 308 cases after trimming and deburring. If the lee tool is not used straight, the end of the tool rubs on the case body and leaves those lines. Took me a while to work out the cause.
    Those tools are not much chop anyway, and a Forster one sits on my bench now

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  16. Josh says:

    I actually had some slightly raised rings similar to the ones shown in pic 6 which looked to be signs of incipient case separation at first glance. The rounds were factory new and shot out of a new barrel so case separation was quickly ruled out but i still didnt feel comfortable reloading them. After closer inspection and showing them to a buddy we figured it out to be from the walls of the chamber not being reamed out properly. This barrel was purchased after Sandy Hook and i was talking to a gunsmith who td me he had personally seen many firearms come in for repair around this time due to AS slipping. I sent the cases to the maker with the barrel and he sent me back a new barrel.

    Like

  17. Steve says:

    What causes the carbon tracks on the case? Mine do not exhibit this problem but I have seen some brass like that. Are these safe to reload?
    Thanks for the great article.

    Like

  18. Pingback: Reloading 101: Case Diagnostics Part II | Sierra Bullets

  19. Joe Tee says:

    Excellent info. Thank you, this has been printd and placed in a looseleaf book I keep with what I feel is very important information…………….Thanks again! Joe

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  20. Brian Dickey says:

    Pics 4 and 5, I have several cases like this and these cases get stuck in my dies. Is there a way to re-size these. I have probably 1000 cases all with the same issue, when I’m running thru the sizing die (with lube) they get stuck and the rims tear off, I end up taking a pair of pliers and twisting the cases out after I heat them with a torch.

    Like

    • firstriverbend says:

      I use Hornady Unique case lube and have no trouble sizing brass like this and worse. I also use it for reforming brass and it has been the best stuff I have found. Almost no effort with it in my Pacific press.

      Like

    • This would lead me to ask a couple of questions. Is this brass that you have fired from your firearm, or is it range brass that has been picked up? What cartridge are we dealing with? – Duane Siercks, Ballistic Technician

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      • Brian Dickey says:

        These are .223 and 5.56 brass, the brass gets stuck in the dies near the base of the cartridge, I had a few get stuck on the shoulder but that was taken care of by annealing the brass. Most of this brass is out of my AR, and has been fired at least twice may be three times. I just finished making about 2000 rounds that were once fired with out a hitch or a hic-up so I don’t think it is my dies or my process. I use Hornady case lube and have tried Lee case lube with no better success. The cases are other wise in good condition and clean up nicely with no visible defects with the exception of the bulges like in Pics 4 and 5. I just hate the idea of trashing a bunch of cases just because I cant get them to feed thru my dies.

        Like

      • Tumble them and get them real clean, then use Imperial Die Wax for lube. I have not had the best success with the spray on lube either. The Die wax is used by putting some on your fingers and applying it to the cases. – Duane Siercks, Ballistic Technician

        Liked by 1 person

  21. Brian Dickey says:

    After doing some home work and watching Youtube videos with people lubing their cases, I decided to have another go at it. I ended up using lee case lube straight and diluted with great success. I determined that I was being to much a miser with my case lube, now the only issue is that i’ve got case lube everywhere, so now i’ve got a mess to clean up but I managed to cycle about 250 rounds thru decapping and resizing with no problem. Sorry my bad, I guess I should not be such a penny pincher.

    Like

    • firstriverbend says:

      Too little lube or the wrong kind of lube, is the most common reason for stuck cases! One of the reasons I like to use the Hornady Unique case lube or the Imperial Die wax is neither is messy, takes very little lube, means no dented brass from excessive lube and I would say always keeps brass from sticking in the die!
      When I started using these wax style lubes, it made a noticeable difference in amount of forced needed to resize brass compared to all of the others lubes I have used over the years.
      Another thing very nice about the wax style lubes is I use my fingers to apply it and you immediately notice most problems with your brass! It also cleans off the brass very easily. 🙂

      Like

  22. Brian Dickey says:

    Just to say, I inspected the cases and primers as indicated above and found most of the reloaded brass had flat primers, I’m loading abut 26.5 grains IMR 8208 xbr on 55 grain rounds. So I think im pushing it a little on the hot side, may be I’ll back it off a little and extend my case life.

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    • firstriverbend says:

      Coupled with the bulges in your brass, I would be tending to think you need to discard that brass. From Hodgdon’s page on 55 grain bullet with IMR 8208xbr “25.3 grs. 3,268 fps 53,100 PSI for a maximum listed load, you are definitely pushing the outer limits of your rifle. Most likely more than a little on the hot side. I would suggest reducing the load to at least the maximum suggested load, as your description shows well past a prudent load, and extend not just the brass life, but the life of the rifle.

      Like

    • firstriverbend says:

      Sorry, forgot to include the link http://www.hodgdonreloading.com/data/rifle

      Like

  23. Brian Dickey says:

    Ohh, and Thanks for all the help and info.

    Liked by 1 person

  24. Steve L says:

    I have seen some cracks along the neck of my 223 using 20.0gr of H4198 (for an AR15). No primer flattening. Federal brass that was only fired once. I cannot ascertain if this is a crack throughout the metal or a deep scratch. Needless to say it goes in my scrap container. I have found similar ‘cracks’ on several cartridges from that batch. I do check my powder weights religiously and I use a single stage Hollywood press/Lee dies with a light crimp in the cannelure.
    At what point does it become necessary to start annealing your brass? I have attributed the crack due to hardening of the brass. I do struggle with the fact that after one reload the brass would ‘need’ to be annealed.

    Like

    • firstriverbend says:

      Steve,
      Have you checked with Federal? I years ago had some Remington brass which was good for only one loading in a .303 British I had. Every other brand worked well for multiple loadings. Turned out they had a lot of brass that was not completely in spec for that caliber. Put me off Remington for a few years, but now I have forgiven them. 🙂

      Like

    • The number of loadings may not be the issue. Time or age is a huge factor. Brass hardens with time, especially loaded brass. New factory ammo may split the necks if the ammo has been setting on a shelf for quite sometime. Brand new cases that you have bought as a component may be too hard just simply due to being several years old even though they have never been loaded. If you start getting neck splitting it is certainly time to anneal. – Duane Siercks, Ballistic Technician

      Liked by 1 person

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