Ruptured case

Reloaded 9mm the other day, and shot them through my S&W 9mm 2.0, with the pictured results. Both were military brass which showed nothing abnormal upon initial examination, and sized, loaded and chambered normally. Fairly stiff load.

After the event, I checked my stash of 9mm cases and found several more with the same headstamp. Upon examination, I found that they were expanded to the point that they would not enter the chamber of my pistol. My guess is that these were fired in a subgun or something with an abnormally large chamber, and when I resized them the sizing die set up a stress riser at the case web.

No harm done, but I just thought I’d post a heads up.

Always nice to have as much information as is available. Maker of brass (US or Foreign) might make a difference if it is thicker and heavier than the commercial brass commonly used. One reason to sort brass by maker. Was this a heavy for caliber bullet or something close to the nominal factory weight bullets. Some of the cases now have that inner shelf, and perhaps this is one of those cases, you might check for that. It might turn a normal load into something a little hot.

At first blush, you think probably an oversized/stressed case is the issue. Perhaps so, but if the information is available, perhaps if you can put it out there, it might be something else. Dusty

Well, they were WCC 95 military cases, and as I said when I went through my stash I found several more of them that were expanded to the point that they wouldn’t enter the chamber of my pistol. I said that this was a fairly stout load, but I have learned that it is actually near the top end for a 147 grain boolit (Blue Bullets coated, 4.0 HP38). Primers looked normal on the other brass, so I doubt it was that hot.

At any rate, I’ll be looking over range pickup brass more closely in the future.

ive never seen pistol brass fail like that. Ive seen lenghtwize splits from brass pushed past its lifetime but never that. It almost (at least in the top pic) looks like you have a chamber ring in your gun or it possible is firing out of battery. Just above the base it looks bulged substantialy. So much so that if it were there when you loaded I think you would have noticed and I doubt it would have chambered even if it wasn't caught and once fired in your gun should have taken the shape of your chamber. One thing for sure is that's a new one on me and I'm just guessing.

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Originally Posted by Lloyd Smale

ive never seen pistol brass fail like that. It almost (at least in the top pic) looks like you have a chamber ring in your gun or it possible is firing out of battery. Just above the base it looks bulged substantialy. So much so that if it were there when you loaded I think you would have noticed and I doubt it would have chambered even if it wasn't caught and once fired in your gun should have taken the shape of your chamber. Never again!

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I've experienced something similar before using range pick ups; a very dangerous situation. I concluded as did Lloyd, that the case did not seat fully, though it may have appeared to have been. Maybe due to slightly bulged cases. After that I have used a case gauge on every round to ensure this never happens again. One can use the barrel and do a plunk test which is just as effective.

If this is range brass pick ups, How many times has it been reloaded before it came into your possession? Brass will work harden where ever its being worked. The mouth neck case head. It does show more in a rifle case loaded many times. section a rifle case that's been loaded many times and you will see a ring in the body at the case head. The body expands to fill the chamber the solid case head doesn't working stretching the brass. Pistol cases do this at a slower rate but it happens.

Being fired in a sub machine gun or one of the pistols with a unsupported chamber can cause this bulge also and swelled case heads. Another cause that does this is a full or semi slightly out of time starting extraction before pressure has dropped and the case still gripping the chamber walls. This is more so on gas operated firearms.

First, range pickup brass can be anything from once fired to reloaded 20 times already. And, it could have been loaded way above sensible limits by the previous person(s). This is the hazard of using unknown brass.

Second, you are correct, there are many 9mm weapons out there with larger chambers. If these have been reloaded, ie sized much smaller and fired/expanded a lot again, they will be very weak.

Third, that split looks to be on the unsupported section of your barrel. I don't know what the S&W barrel looks like so can't make a definitive statement. Typical failure spot.

Fourth, you say it was a stiff load. More so than standard 9mm or above +P load? If above +P load then you need to back off a bit. FWIW, primer condition is not very reliable indicator for determining overloads. If I get a flattened primer in my 9mm it is WAY too hot.

Last, I'd take every one of those you found and crush, then trash them. If loaded I'd pull the bullets and crush them.

Thanks to all who responded. I have gone through my stash and discarded anything that looks suspect, and pulled and discarded all the loaded rounds with that headstamp. I have used that load before with no ill effects, and though I still suspect the case, I plan to reduce it in future loads, just to be on the safe side.

I suspected firing out of battery, too, but cannot duplicate the problem manually.

The crescent failure of the case puts me in mind of the older Glock .40s, with their poorly supported case heads, but my Smith has a well supported chamber.

I've had a case fail exactly like that in my R-51 9mm. Yes, it was a range pick up. I'm not sure if it's the cause but my thought was that the case had most likely been fired in an unsupported chamber and maybe more than once. I now run both 9mm and 40S&W range pick ups through a Lee Bulge Buster and it's easy to feel it the case is oversize in the web area. As plentiful as these cases are, I just throw any suspect cases in the recycle bucket. Gp

The Smith will not fire out of battery when the trigger is pulled in a way that would cause any type of case failure. I would be glad to explain that, but too often we get that conjecture here from people who really do not understand how pistols work.

There are all too many, and I am doing my best to enlighten.

Whenever you see something that looks like the case was subjected to too much pressure, too much pressure being present is the vastly mostly likely way to bet.

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Originally Posted by gpidaho

I've had a case fail exactly like that in my R-51 9mm. Yes, it was a range pick up. I'm not sure if it's the cause but my thought was that the case had most likely been fired in an unsupported chamber and maybe more than once. I now run both 9mm and 40S&W range pick ups through a Lee Bulge Buster and it's easy to feel it the case is oversize in the web area. As plentiful as these cases are, I just throw any suspect cases in the recycle bucket. Gp

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I'm helping a friend learn to reload 9mm and Lee said there was a taper in the 9mm that would not allow the bulge buster setup to work properly. We came up with another option, but it is not a recommended fix. The bulge was probably shot in a Glock, and is commonly known. Once a bulged case has been resized with a bulge buster, I don't think it would be a good idea to run in a Glock again. (A little off topic) The reason being the case has been stretched once already and if fired in an unsupported chamber could rupture if it happens to land in the chamber with the same orientation. For this reason, I was advised by one of the major die manufactures not to reload bulged 9mm in case someone else picks up the brass and fires it in an unsupported chamber. Don't know from personal experience, only researching for my friend.
Just my personal opinion.

Were you loading mixed brass? Some commercial and some Military surplus?
If it was a stiff load in commercial brass, then it could have been way over pressure in Military brass.
I'm not sure how picky the 9mm is on the subject, but I know first hand that 45acp case internal volume can raise pressures in a huge way.
It was my first time loading for 45acp, way back when, and i used some TZZ Israeli brass that I picked up from a qualification while onboard the ship. I used my buddies recipie with a 230 LRN and 4.7gns of 700X without reducing and working up... His load(4.7gns of 700X) in commercial brass gave around 890fps, in the TZZ brass they went over 1300fps!! I backed way off and worked back up shooting over the chronograph until I hit 900fps at 4.2gns.
I always sort my 45acp brass now.

fast Ronnie: You are correct that the bulge buster using the 9mm Luger die is not advised. You need to use the 9 mak die on the BB for 9 Luger. Gp

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Originally Posted by lar45

Were you loading mixed brass? Some commercial and some Military surplus?
If it was a stiff load in commercial brass, then it could have been way over pressure in Military brass.
I'm not sure how picky the 9mm is on the subject, but I know first hand that 45acp case internal volume can raise pressures in a huge way.
It was my first time loading for 45acp, way back when, and i used some TZZ Israeli brass that I picked up from a qualification while onboard the ship. I used my buddies recipie with a 230 LRN and 4.7gns of 700X without reducing and working up... His load(4.7gns of 700X) in commercial brass gave around 890fps, in the TZZ brass they went over 1300fps!! I backed way off and worked back up shooting over the chronograph until I hit 900fps at 4.2gns.
I always sort my 45acp brass now.

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Mixed brass. I had no idea the pressures could vary so much. Thanks for posting.

Those look they were fired from a Intratec Tec 9 ( a failed semi smg pistol)!

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For years I shot 308 and 223 in NR high power. new or once fired cases were loaded 3 times for 600 yds stage then 3-4 times for 200 and 300 yds stages. Then used for practice brass, when I felt they were done there they went in the range bucket to be sold for scrap brass and support the juniors program. Many times I saw guys picking that brass from the bucket with 12-25 loadings on it, thinking they were getting something. The trend to bigger chambers to aide feed and function cost a lot in brass life

If leaving brass that is no longer safe to use in a public range bucket, crush it. Do not leave it knowing it maybe reloaded again while knowing it is not safe.


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You might also want to check your crimp. If your crimp is too tight it will cause a pressure build up in a case that may not be that strong to begin with.

Ive seen bulged glock shot brass before and it NEVER looked like that. It never had a pronounced bell shaped bulge like that. It was more of a belly on the bottom third of the case. As a matter of fact ive never seen a big problem with 9s even in glocks. Its the 40s and 10s that seem to bulge in my experience. The bottom case could have been caused by a number of problems and if I hadn't seen that top one id say it could be caused by over worked brass or excessive pressure but the poster said he was using book loads so i have to about rule that out.

Yes you can pick up overworked brass at the range. That said around here anyway most of the shooters shooting 9s and 40s are shooting factory ammo. I have no qualms at all about picking up range brass around here. there just isn't but a handful of handloaders around and i know most of them. One thing that can happen with handloaded 9s and 40s are slam fires caused by primers not seated properly. Ive seen some try to seat primers in cases that have crimps and leave the primers protruding. One thing i do to all my 9 and 40 brass is before i use it i inspect it. Look for obvious signs its not once fired. Like the wrong color primer for the brand, champered case mouths ect. Then i run all of it through my Dillon primer swadger and tumble it. Once its clean i inspect again for splits cracks ect. If it looks bulged i run it though a buster but its rare i find it like that.

I get some bulging with glocks. Mosly like i said in my 40s and 10s. It rarely gets so bad that the brass wont chamber. Once its gone through the bulge buster that's it. I don't do it a second time. I don't want to work the brass more then nessisary and find that if the brass is used in the same gun it usually chamber just fine even with a slight bulge. Some get all scared of bulged brass. Ive shot 10mm bulged brass at least 10 times without any problem. I do use cast bullets (like most here) and don't push any of the black guns to factory levels. Top end book loads are actually pretty conservative compared to most factor ammo. Its rare to find but some books will give plus p loads and those should probably be avoided. Like i say I'm guessing just like EVERYONE else here. If i had to take my best guess id say that gun slam fired out of battery due to a high primer but have to say the primer should be flattened if that's the case and it doenst appear to show any signs of high pressure or slam firing. Brass cant swell any more then the size of your chamber so if you had a bulge like that it wouldn't chamber and if your chamber was that sloppy it would be doing it to ALL your brass loaded at the same level. Ill add that ive never seen an m&p that did that to brass and at least MY m&ps are fairly tight chamberd guns. A lot tighter then my glocks so i seriously doubt your going to even get brass that bulged to get into the chamber and its more the norm then the exception that fired brass out of any other gun will chamber in my smiths without sizing. Heck mine have problems with 358 bullets. So whats my conclusion. Its that i don't have a clue.

Entirely possible a result of corrosion. Could be either at rim or inside if it has been wet any period of time.

Glocks aren't the only firearm that had/has un-supported chambers. Brass picked up at the range with round primer hits (top piece of brass). 2nd & 3rd pieces of brass show a bulge in them. The bottom 2 pieces of brass had the "bulge" sized out of them, note the double wear rings/marks on them.
[IMG]https://i.imgur.com/8DmYoVO.jpg[/IMG]

The brass pictured above was factory ammo shot in a s&w shield.

This is what starline says about their 9mm brass:
"9mm brass: also known as 9mm Parabellum, 9mm Luger and 9x19mm. This cartridge is now one of the most popular pistol cartridges in the world. **NOT RECOMMENDED FOR USE IN S&W SHIELD PISTOLS WITH NEAR-MAX OR +P LOADS, DUE TO POORLY SUPPORTED CHAMBER CONDITION**

A link to starline 9mm brass
https://www.starlinebrass.com/brass-...M-Luger-Brass/

Myself, I only use ww/federal/blazer 9mm brass. There's always a bunch of it laying at the ranges in my area. I do inspect and sort anything 9mm brass I pick-up even though it's factory ammo. I do use remington once fired 9mm brass for long bodied bullets, the remington brass is thinner than the ww/fed/blazer.

I don't have a 9mm shield but do have one in 40sw. Ive never noticed any bulging with that gun. For that matter never with any gun I have including glocks except for my 20 and 29. If I push them to full power levels they do bulge slightly. I guess my luck could be contributed to the fact that in my 40s I don't push them right to the absolute last fps. I do with some of my 9 loads though and have shot them out of m&ps, glock 19 and 43 and two different ar15s and have never seen a bulged case after being shot in any of them. Ive never even found a piece of once fired that had a bulge where the chamber was unsupported. Ive seen some bulged a bit on the whole case from being shot in large chambers though.

At a Police auction many years ago I picked up a CZ-75 Clone, witness in 9mm. It was a lovely gun and the wife nabbed it right out of the box as soon as I got home. When we took it to the range, it spit out brass with a huge bulge. I looked at the barrel and someone had taken a dremel to the feedramp and really did a number on it. I looked at new barrels, but they were about the same price that I paid for the gun. We ended up trading that gun off to someone that didn't reload and bought the wife a new one.

I’ll end this cautionary tale with a pic of the brass in question. The three rounds on the top were as received, right out of the tumbler. The three on the bottom were after resizing. If you look closely, you can see the incipient case rupture, just waiting to happen. So I guess the bottom line is, if you use range brass, be aware that it could have been fired in a subgun or something else with an oversize chamber. These entered the sizing die just fine, and gave no indication of a problem until a couple slipped by me in the reloading process.

Let’s be safe out there.

My Tec 9 would do that to brass, switched to steel cased and it was much happier

Have a CVA stalker in .223. Would shoot 0.5 moa. Noticed it was bulging the brass near the base but was worried about safety. Contacted CVA, they had me send it in and they gave me a new barrel. Seems they manufacture the barrels as .222 (that is what is stamped on the bottom anyway). I think when they ship them to America, they probably manually ream them out to .223. Guessing someone got the reamer off a bit when they were reaming it.

Rosewood

had to bring this one back because Ive seen it 4 times this summer in my own guns. What I think ive found is (both are ar15 9mms) that some of the ammo I had was had two problems. first it was a top end book load and I usually down load 9s a bit. Added to that I seated bullets out a tad to far and whats happening in my guns is there firing out of battery. Seems an ar15 in 9mm isn't like a 556 and will fire without the round all the way into the chamber. Both by the way also have a small amount of unsupported chamber. A couple also hung up and fired and blew out on a batch of ammo I didn't have enough crimp on. Apparently the sharp edge of the case rim caused enough drag that the round didn't go all the way into battery. Since ive found these problems I seated a bit deaper backed the load off and crimped a bit more and have put about a 1000 rounds through them since and haven't had a problem. Sure does wake you up though. Twice it blew the mag right out of the mag well. You wouldn't want to be holding the gun by the mag or mag well when one blew.

It is impossible for a Shield to fire out of battery with a pull of the trigger and have a case failure result from being “out of battery.”

Cannot happen. A lack of understanding of how these pistols function contributes to this unfounded presumption.

I guess its kind of questionable that a round IS fully in battery if its in an unsupported chamber.

kind of stumbled on a cure for my problems. I saw on line somewhere where a guy suggested a lee underized sizing die (basically a small base sizing die for 9mms) I bought one and loaded up 500 rounds (even used my old tired brass) and shot them over a couple days and never had a single blowout. Rounds will no go fully into battery even in a dirty chamber. Some even claimed better accuracy because it sizes down the part of the case that holds the bullet to a smaller diameter and that increase case tension on the bullet. I did run a few rounds for groups out of my 16 inch gun and didn't see an improvement but that gun will about shoot one hole groups at 50 yards anyway with about anything I throw in it. Need to try it in my 4.5 inch ar. Its a bit more accuracy challenged.