CM9 Blown

[higgsjunk]

Let me start off by saying I'm a long time reader of the fourm and want to thank everyone who posts all the great information.

Now my story...

I have owned my CM9 since the end of 2011 and have fired over 700 rounds through it without any problems what so ever until last Friday..

https://lh3.googleusercontent.com/-kcJWu0CnuvM/UV9Muy1cTzI/AAAAAAAABu4/QC0ygvHSQjw/w490-h367-p-o/20130405_180602.jpg
https://lh6.googleusercontent.com/-8VPHotpQ2O4/UV9M1EeWDaI/AAAAAAAABvA/ICvG_3rVfMM/w549-h412-p-o/20130405_180451.jpg


This is the gun I carry to protect my family.. Here is one last picture.. Take a close look at how much of the case is out of the barrel... Is this something that Kahr needs to recall?

https://lh6.googleusercontent.com/-wMKjPBrUFgE/UWNX_fiysCI/AAAAAAAAByo/szieCJIt0Js/s1136/20130408_194136.jpg

I have contacted Kahr and they have instructed me to send it in (overnight on my dime) for inspection/repair. Just wanted everyone's thoughts..

Thanks,
Brandon

[Bawanna]

First welcome higgsjunk. I'm sorry that we meet under these not so good circumstances.

It won't help much but we have to remember that this most likely was not the guns fault, it's not uncommon in several brands to not be fully supported.
I suspect this was a hot round, picture looks factory but could be a reload too. Maybe a double charge.

On the good side it looks like a new side cover, an extractor and perhaps a spring in the extractor chain and you should be back on the track. Provided there wasn't a squib situation and the barrel isn't bulged. Even the trigger bar spring looks intact.

Apparently Kahr feels it is an ammo issue as well or they would send a pick up tag and cover the shipping. If it turns out to be a gun issue the may rethink that also but I don't see that happening as it sure looks ammo related.

I'm sure this doesn't help much but know that we all feel your pain and suffer the waiting with you while your gun is off getting a makeover.

I put a double charge once through my PM45 but it held up, I sure knew it wasn't right though.
I can't imagine what that must have felt like to have the side cover blow off in your hand, had to be major scary.

[jocko]

lets not bnlame thegun for a bad round. It is what it is. many guns show a partial unsupported area. I know alot of the glocks show that. Had it blown with a casing fully inside the chamber, u might have vblown the damn gun apart also. The fact tha tu have shot 700 round sthorug thge gun should tell u sumpin, like all is well whent he rounds are not bad rounds.....

If u feel better about paying 60$ to sendit in and have kahr look at it, then indeed do it, they are gonna replace that back side cover for u no charge and skend the gun back for they will find nutting wrong OR u can just order or ask kahr to send u that back cover and save the bucks and reinstall it yourself. The gun did its part, the ammo sure didn't.

[Bawanna]

My only concern would be the condition of the tiny little screw that holds that side cover on. It looks like the screw is still there so it may be fine, take it out put the new on and move on, but if it popped out they may have to rethread or even replace the frame. I doubt that would happen.

Might be good insurance to have it completely checked over.

[jocko]

looks to me like the screw heldto. Thatwouldbe aneasy fix if itdidn't hold, good ol fingernail polish in tha thold and send the screwin and ur good togo. Thereis no pressure thereexcept when a casing blows.

Iguess my point is and I cerainly never wantto disagree with the colonel,is fix thefokker urself and if the gun acts up, THEN send it back to kahr and let them do theiur thing with it..

[scosgt]

No one asked if this was a reload!
If it was, the answer is obvious.
But the next question, was this a JHP round that had been used as the top round for loading a few times? It could have been a case of bullet setback. It does not take that much setback in a Glock .40 to yield a KABOOM, so it is quite possible in a 9mm as well, as the pressures are similar.
Beyond that, if it was a virgin factory round, it could just have been a defective case. It can happen.
In which event, there should be a case against the ammo maker for liability.

But I would look at the above issues first. Blowouts are not all that common in 9mm. My department shoots over 13000 rounds a week of 9mm since 1995 and I have never heard of a case blowout.

I have seen a few personally in .38 spl, usually the brass has been worked too many times, but I never had a catastrophic failure. But then I am always conservative on my powder charges.

[scosgt]

Looking at the picture I do not see signs of excess pressure on the primer. In fact, not at all. Not blown out, no flattening, not pierced.
Looking at the close up of the case head, it looks like it may have been fired more than once, although you can not really tell. I am guessing a reload. Brass may have been over worked.

[jocko]

good positive questions. nice post scosgt. now why did not the colonelk think of that and save everyone alot of grief. Stay coool under the rock greatone BUT stay under therock.

[wyntrout]

Dang! When my P9 did that... with "factory reloads"... I just pressed the side plate back in place... after putting the trigger bar and spring back under the slide, put my spare PM9 extractor in and pressed on shooting. It wasn't the pistol's fault! Some weak-assed cases were rupturing. I finally stop testing or getting rid of the suspect cases by shooting them after my K9 extractor blew out! Those things are about $16 each + shipping... so I do have some spares. I also carry the tools for stripping down the slide... just in case.

Wynn:)

[Bawanna]

I mentioned the reload in my first post you old goat!

I'm getting poor internet connectivity under my rock, might be out of touch.

Jocko, that means I can't get hooked up too good on the crystal ball, like a Raid Dead Zone for ants.

[jocko]

ok, I missed that part, u can come out of the rock. My bad.Time for NCIS to come on,so Diva is my DIVA. Tony realy wants to nail her. U can see it in his and her eyes to. before the season ends they will at each other like there is no tomorrow. Don't ask me how I know all of this. Just sayin

[Bawanna]

Aww thank you, I was getting lonely and tired.

[higgsjunk]

Thanks for all the comments and suggestions..

Let me start out by saying that I know the ammo is what caused the problem. For the record, it was factory ammo fresh out of the box, not reloaded..

My issue is how the gun handled the blown case. Not a fan of things blowing off the gun I carry to protect myself and my family.. Am I way off base here in thinking that the barrel should support all the case and not have that cutout i'm showing in the 3rd picture?

I'm not trying to say the gun is a piece of crap.. I love this gun!!

[jimsea]

Kahrs design is common and we can see what happens when a casing blows when the round is partially supported. It appears detonation will take the path of least resistance which didn't include out the barrel in the OP's gun..

Anyone with first hand experience of what happens when a casing blows when the design of the pistol fully supports the round? I have never come across this.

[Ikeo74]

Thanks for all the comments and suggestions..

Let me start out by saying that I know the ammo is what caused the problem. For the record, it was factory ammo fresh out of the box, not reloaded..

My issue is how the gun handled the blown case. Not a fan of things blowing off the gun I carry to protect myself and my family.. Am I way off base here in thinking that the barrel should support all the case and not have that cutout i'm showing in the 3rd picture?

I'm not trying to say the gun is a piece of crap.. I love this gun!!

OK, I am chalenging the validity of your picture that you are claiming that the case is unsupported. I am also offended by your claim of non support. Evidently you did not have the barrel locked into the slide and that unlocked position showed more ot the case making it "appear" to be un supported. In fact, the case "IS" fully supported.
A better way to check support is with the barrel completely removed from the gun. Drop in a live round and take a flashlight and visually check all the way around the case. There is only a very small area of the case visable at any area around the entire case. There is absolutely no half moon unsuppported area that you are showing in your picture. You are inferring that there is a problem where none exists. Now take your caliper and measure the inside case depth of a fired case with the depth measure end of the caliper. Withdraw the caliper and using the protruding end part of the caliper without changing the measurement, hold it on the outside of the case and you will see the peg does not extent beyound the area you could see with the flashlight while looking at the seated bullet. You can do the measurement with a fired case to make it easier. Your bullet failure was not due to an unsupported case, no way. I have a CM9 and everything I have said here I have verified on my own gun. :mad:

[Ikeo74]

No one asked if this was a reload!
If it was, the answer is obvious.
But the next question, was this a JHP round that had been used as the top round for loading a few times? It could have been a case of bullet setback. It does not take that much setback in a Glock .40 to yield a KABOOM, so it is quite possible in a 9mm as well, as the pressures are similar.
Beyond that, if it was a virgin factory round, it could just have been a defective case. It can happen.
In which event, there should be a case against the ammo maker for liability.

But I would look at the above issues first. Blowouts are not all that common in 9mm. My department shoots over 13000 rounds a week of 9mm since 1995 and I have never heard of a case blowout.

I have seen a few personally in .38 spl, usually the brass has been worked too many times, but I never had a catastrophic failure. But then I am always conservative on my powder charges.
SCOSGT, Your bullet setback theory is more likely. Help me out here and if you still have your Kahr do the check for support that I outlined and post back your results for support or no support here on this post.

[scosgt]

Mine is a CM40.

[Ikeo74]

Mine is a CM40.
The support in the barrel will be the same as a CM9.

[CJB]

I don't wanna piss in anybody's Wheaties, but can someone explain how ammo got that far out of the chamber before the case blew? Thats the point where the barrel is just beginning to lock up to the slide. The bullet should have been long gone, and chamber/barrel pressure well safe before the case began be with drawn from the chamber. That last part can be proven by physics, should anyone want the math, I'll be happy to provide it.

I see another problem. I see... and I'm sorry to say, the striker stuck forward, causing a slam fire.

Just my call without seeing the situation in person.

[Ikeo74]

I don't wanna piss in anybody's Wheaties, but can someone explain how ammo got that far out of the chamber before the case blew? Thats the point where the barrel is just beginning to lock up to the slide. The bullet should have been long gone, and chamber/barrel pressure well safe before the case began be with drawn from the chamber. That last part can be proven by physics, should anyone want the math, I'll be happy to provide it.

I see another problem. I see... and I'm sorry to say, the striker stuck forward, causing a slam fire.

Just my call without seeing the situation in person.
A slam fire could have cause the bullet to fire before the lock up, I say that is very possible if the striker was in front of the striker safety instead of behind it. The owners manual talks about that problem and how to correct it and also how it happens. A slam fire would be a user error in re-assembly of the gun after cleaning.

[wyntrout]

When I had the case ruptures, my case weren't as badly ruptured as that one. I think mine were due to poor cases, but this case looks like maybe a hotter load and weak case. I've had three instances of extractors blowing out... from the same cases that I isolated and was trying to get rid of by shooting them. I only found one of the extractors and I lost one pin because I didn't realize the extractor was gone, but saw on camera later that the pin was hanging out when I tried to chamber another round. The pin fell out and I couldn't find it. I only found one of three extractors and I still don't know why it was under my feet after I cleared my area of everything... down to bare floor, but later as I was getting ready to leave, there it was under my feet!

My side P9 plate is pinned, but the plate slipped over the retainer thingy on that side of the pin and I removed the pin, and just pushed the plate in place, and then inserted the pin.

My P9 experience:

http://www.kahrtalk.com/showthread.php?t=15235&highlight=P9+ruptured

Wynn:)

[olympicmotorcars]

So what brand of ammo was it, just in case it was ammo related ?

[Ikeo74]

So what brand of ammo was it, just in case it was ammo related ?
The original poster has not said yet and he is off line at this time.

[wyntrout]

In his picture of the ruptured case it's a WIN headstamp. If that was new ammo, I would be talking to Winchester for my repair bill and the shipping! I'm sure Kahr will fix it, but not for free. That round looked worse than mine... more powerful load!

Wynn:)

[Ikeo74]

The main reason for my posts here is to clear up the claim that Kahr Barrels are not supported. :Amflag2: Kahr barrels are supported.

[scosgt]

A slam fire could have cause the bullet to fire before the lock up, I say that is very possible if the striker was in front of the striker safety instead of behind it. The owners manual talks about that problem and how to correct it and also how it happens. A slam fire would be a user error in re-assembly of the gun after cleaning.

In a slam fire, wouldn't the primer back out since it ignites before it is held by the bolt face?

[Ikeo74]

In a slam fire, wouldn't the primer back out since it ignites before it is held by the bolt face?
Someone else will need to answer that because I have never had a slam fire. No experiance with any slam fires. Anyone have one?
I can see a possibility of the blowback pressure keeping the case aginst the bolt face until the case ruptured.
I have a sig 230 in .380 cal which does not lockup the barrel, it's a blowback design and primers have never backed out.

[scosgt]

I don't wanna piss in anybody's Wheaties, but can someone explain how ammo got that far out of the chamber before the case blew? Thats the point where the barrel is just beginning to lock up to the slide. The bullet should have been long gone, and chamber/barrel pressure well safe before the case began be with drawn from the chamber. That last part can be proven by physics, should anyone want the math, I'll be happy to provide it.

I see another problem. I see... and I'm sorry to say, the striker stuck forward, causing a slam fire.

Just my call without seeing the situation in person.

Can you explain more about the Kahr slam fire? Is this after slide detail strip, or just field strip for cleaning?

[jimsea]

Can we also discuss further the obvious differences between supported and unsupported barrels?

[higgsjunk]

Maybe I'm confused.. Here is a pic of the barrel out of the slide with a factory loaded speer gold dot 124gr hp shoved in as far as it will go and as you can see, the case is not "fully" supported.
https://lh5.googleusercontent.com/-thgZNIO_uQ0/UWNXU6bPS7I/AAAAAAAABxc/VeQcc4I1nx4/s1107/20130408_192130.jpg
I'm not trying to play tricks or take pictures at funny angles here..

What am I missing???

[Ikeo74]

Maybe I'm confused.. Here is a pic of the barrel out of the slide with a factory loaded speer gold dot 124gr hp shoved in as far as it will go and as you can see, the case is not "fully" supported.
https://lh5.googleusercontent.com/-thgZNIO_uQ0/UWNXU6bPS7I/AAAAAAAABxc/VeQcc4I1nx4/s1107/20130408_192130.jpg
I'm not trying to play tricks or take pictures at funny angles here..

What am I missing???
Now measure the inside depth of a fired case and you will see the part of the case you can see in this picture is solid. The inside cavity is not deep enough to reach that area.

[scosgt]

The only part of the case that would normally be said to be "unsupported" is the part right over the feed ramp. Usually there is the need to have some angle there for the case to feed properly (on a handgun, rifles can be way different, with straight line feeding in some cases).
In your picture, the part of the case you can see is the head. It is solid brass. That is not what blows out in an unsupported situation. It is the thin case walls forward of the head.

[wyntrout]

That's pretty normal. I just did that to my PM9... looks the same. 124-gr Speer GDSB in chamber.

Wynn:)

[scosgt]

I don't have a picture host so I can't post a picture, but I just looked at my Glock 27 and the entire head is way more supported. Just about the only thing not in the chamber is the extractor groove.

Hmmm

[scosgt]

That's pretty normal. I just did that to my PM9... looks the same. 124-gr Speer GDSB in chamber.

Wynn:)

Compared to my G27 that is pretty much unsupported.

[Ikeo74]

If anyone wants to take a picture of their glock, then the OP can see what a true unsupported case looks like.

[Ikeo74]

I don't have a picture host so I can't post a picture, but I just looked at my Glock 27 and the entire head is way more supported. Just about the only thing not in the chamber is the extractor groove.

Hmmm
The extractor grove "IS" the unsupported area of the glocks. That is why a lot of people don't like to reload glock fired cases because there is always a bulge in each and every fired glock case.

[scosgt]

Figured it out. I think you can see the case is totally supported. Sorry about the crappy iPhone pic. Look carefully, only a few thousandths of the case head is not supported.

[wyntrout]

Yup... right here... a New G19 with only 250 rounds through it and a 124-gr Double Tap GDHP inserted.

Wynn:)

[scosgt]

If anyone wants to take a picture of their glock, then the OP can see what a true unsupported case looks like.

You mean what a true supported case looks like.

[scosgt]

Yup... right here... a New G19 with only 250 rounds through it and a 124-gr Double Tap GDHP inserted.

Wynn:)

That is WAY more unsupported than the G27!!!

[wyntrout]

It doesn't look any more supported than the Kahrs.

Wynn:)

[scosgt]

Obviously the 9 and the .40 are way different. The G27 is FULLY supported all the way around even over the feed ramp.

[wyntrout]

My new and unfired G22 is a little better, but the photos didn't come out as well... 180-gr Bonded Remington Golden Saber inserted:

Wynn:)

[Ikeo74]

Maybe those pictures would show more detail tommorow during daylight hours or under a bright desk lamp. It's really hard to see how they are supported.

[scosgt]

Apparently Glock gives more respect to the .40 than to the 9mm.

[wyntrout]

I would hope so!:D

I re-shot the G22 pix.

My cartridges are all nickel-plated. The CFL lights make them seem brassy in some angles.

Wynn:)

[CJB]

Can you explain more about the Kahr slam fire? Is this after slide detail strip, or just field strip for cleaning?

Only two ways I know of, that a slam fire can happen, is if you assemble the pistol incorrectly, or if there is some sort of dirt or debris that is holding the striker forward.

Incorrect assembly has been mentioned in this thread. But... some particle... sliver of brass... I dunno what, could have been lodged in there someplace holding the striker forward.

Time to think. Did you pull the trigger, or did the pistol fire when the slide moved forward? If it was distinctly the former, then its not a slam fire.

I just cant see how the case ruptured after backing out a bit, or, how the pistol fired with the case not fully chambered.

OR

With the press on production the way it is... have ammo makers just totally lost it, and they're cranking out problems waiting to happen?

[yqtszhj]

This is a good thread. I didn't plan on learning stuff this early in the morning.

[jimsea]

Looks to me in all the pics I have seen here but best illustrated in this one, that if a case is going to rupture due to defect it will go right at the top of the feed ramp for obvious reasons.

Bad ammo really sucks.

http://www.kahrtalk.com/attachment.php?attachmentid=8225&stc=1&thumb=1&d=1365568344

[Ikeo74]

Looks to me in all the pics I have seen here but best illustrated in this one, that if a case is going to rupture due to defect it will go right at the top of the feed ramp for obvious reasons.

Bad ammo really sucks.

http://www.kahrtalk.com/attachment.php?attachmentid=8225&stc=1&thumb=1&d=1365568344
True statement jimsea. Also take note the dipped out area under the feedramp is not on any barrels made by Kahr, thus my claim that all Kahr barrels are supported is proven to be true.

[wyntrout]

My first "possible" case rupture resulted in my PM9's extractor disappearing. I don't recall any other problem than just suddenly it was gone. I think it was my EDC and I had to use my PM45 when I left the range. Kahr sent me a replacement extractor and I bought some for all of my Kahrs, including some springs and pins. I don't shoot any lead reloads... just use the Atlanta Arms & Ammo Inc. factory reloads sold at the range. They make precision ammo.

The first recognized rupture was with my P9 and the side plate blew off, as well as the extractor. At that point I had added a PM9 extractor and its pins and springs to my spare parts, especially for the range. I put the pistol back together with the spare extractor and continued shooting. I put suspect ammo aside... the remainder of a case of 124-gr FMJ "factory reloads" that I had bought a decade ago. The ruptured case had a "A-MERC 9mm" headstamp and I found 5 more of those in the remaining 150 rounds or so. I figured I would shoot them in the K9... more robust barrel, steel frame, and no side plate.

http://www.kahrtalk.com/showthread.php?t=15235&highlight=P9+ruptured

Next range trip I started firing the last 5 rounds of that ammo and #2 blew out the extractor. I said that was enough, tore the bullets apart, fired the primers, and burned the powder... have a video of the powder burn... kind of funny. Did you know that a short piece of unrestrained cannon fuse acts like a rocket?

http://s1134.photobucket.com/albums/...Powder%20Burn/ (http://s1134.photobucket.com/albums/m620/wyntrout/Powder%20Burn/)

Anyhow, that was my only experience with "factory reloads"... other than AAA, our range ammo in my Kahrs. That Craig ammo I bought well over a decade ago at a gun show for my K9. I did finally shoot up the rest with no problems using the new G19 and/or K9.

One point, though, the point of rupture was NOT at the feed ramp but possibly upper left... 7 to 11 o'clock. One P9 picture shows the case still in the chamber. That was the case in the two recovered shells.

Wynn:)

[jocko]

nuttin wrong with kahrs barrels. If one feels unsafe with them, then best go to anutter gun. Why to we tend to blame the guns when it is bad mmo. With the way today they are pouring out new ammo, it is a wonder we don't see more of this blowouts, Percentages are so so so low in the first place , but it is gonna happen..

[higgsjunk]

Let me give a little more information.. I was shooting a box of 50 rounds, 5 at a time. The bad round that caused all this was the 45th out of 50. The 44th round went off, I reacquired the target, pulled the trigger and the round felt just like all the others except a burning feeling on my hand. Looked at the gun and the side cover was gone as well as the extractor.

Obviously some kind of problem with the ammunition caused this but I don't think the round was double charged, deffinatily was not a squib because the bullet exited the barrel and I had to pull the trigger so it was not a slam fire..

The bad case was still in the gun so I field striped the gun and took a wooden dowel rod and knocked the case out of the barrel.

Now according to the members here on the forum, the barrel supports the round just as well if not better than most other manufactures..

I am just having trouble understanding at what point after i pulled the trigger the case blew...

Can someone take me through the process step by step?

Thanks so much for all the comments.. If there is any other information I have left out, please feel free to ask...

[Ikeo74]

This is only an uneducated guess and has no basis of fact.
I think the case rim had a weak spot or crack near the ejector. When the gun fired the extractor started to eject the case, the case rim seperated and the bullet had not exited the barrel yet. This allowed the internal pressure of about 25,000 psi to blow out of the rear of the case (the hole in the split rim) and blow the ejector out of the gun as the case was being pulled out (ejected) about 1/8 inch out of the chamber to be ejected. That is the closest answer I can think of at this time.

[robdnor]

Well, being that it's a Winchester 9mm, I well simply mention that one of my training partners had 2 squibs from Winchester white box 100 cnt a couple Thursday's back. He contacted Winchester who sent him a return label, they (winchester) did mention that there may be a potential of counterfeits as there was no lot number on his box, then again that may be a generic response to cover themselves, as they did say they were planning to send him 500 rounds
So what I am gettin at is if you still have a couple of the rounds left then you may want to contact Winchester in addition to kahr, see what they have to say about it

Also, fully supported chamber and a case blowout, Ruger mark 3 on Sunday, that sure was fun:confused:
The rear of the casing blew off completely
Not that it's 9mm but it was also Winchester, super x.. And then the back of casing (head stamped) on a couple other casing looked bulged/rounded
Unfortunately I normally throw my 22 in peanut butter jar in the range bag to secure the ammo better than a box, so bye bye box and lot numbers (yes shame on me) Thankfully after inspection, the gun is fine

This leads me to the assumption that the crazy ammo rush may be to blame?

[higgsjunk]

Ikeo74

That makes the most since of any answer Ive been given thus far.. Thanks

robdnor and others..

I'm sure the quality control has went down the drain during this time of ammo shortage but this ammo was part of an old stock i've had for a few years..

[Bawanna]

This type of thing could easily get past any quality control in the best of times too. Can be one of those hidden things that your just not gonna see until something bad like this happens.

I sure hope the major increase in production doesn't create more of this. I believe in my own head that they are still putting out good quality stuff at least I have very high hopes.

[jocko]

squibbs, blown cases can happen to ammo at any age of mfg. If we knew, it would never happen but it is what it is. there really are not alot of guarantees in life..

I have no idea how the quality control works in the reloading either, as millions are made each day so some type of computer system is desige dto catch this stuff, 99.9999995% of the time. Man sure isn't doing it or we would have a squbb per box. I t4nd to lean tow3ards what the colonel said so, Unlessit happens to you like we have seen n thisf orum, I tend to take alot of stuff pritned as heresay sh!t to. Just to be one of the boys type thing..,Just sayin

[wyntrout]

I would hang onto the Winchester box and the remaining ammo and see what they could do for you. It really sounds like a defective case that ruptured at a weak point as the cartridge fired and the case was expanding. That's usually enough to blow the extractor out and sometimes the side panel. I say sometimes because when my PM9 extractor disappeared, I had no clue about the ammo at that time, but it was probably the same A-MERC cases that I isolated after the P9's incident... and stopped fooling with after the K9 extractor went bye-bye!

I would certainly see if Winchester would step up in some way to help repair your pistol or compensate you a bit.

Wynn:)

[jocko]

it only costs a nickel to contact winchester to ask.

[CJB]

If the barrel and the blown case are still around... I'd love to see it IN the chamber again, but not in the pistol. That will give a very good idea of what happened.

[olympicmotorcars]

with all this talk of bad ammo, come to think of it, I had a squib load from a box of winchester white box last month. I immediately stopped and field stripped my pistol (cannot remember which one I was shooting ) and checked the barrel to make sure it was clear.

[mr surveyor]

I'm glad I reload my own.... that way, in the event of an ammo malfunction I can keep my nickel and try to a$$kick myself:D

[scosgt]

First of all, I checked my CM40 and the case head is fully supported. I guess they respect the .40 more than the 9mm

Now here is what REALLY happened. I had to play with my CM40 a bit to verify this, but I am pretty certain...

What happened is that the gun fired OUT OF BATTERY. I don't know why that happened - dirty chamber, burr on the extractor, rough bolt face, out of spec cartridge, I can not determine what caused it.

But think about how the Kahr works. At the instant of firing, the barrel first drops a short distance. I can't find my micrometer right now, so lets call it 1/8". Until the barrel has dropped the entire 1/8", the case does not move back from the chamber. The barrel drop, or lockup, is what allows the pressure to drop before the case is extracted. By the time the case begins to extract, the bullet is supposed to exited the bore, which equalizes pressure. That is why you get brass, but not clouds of hot gasses and bits of metal out of the ejection port.

I discovered that the CM will drop the striker (discharge) with the barrel dropped about 1/2 way (call it 1/16"). That extra 1/16" is the fatal margin. By discharging out of battery, the timing is off, and the thin case wall will be pulled out of the chamber while the bullet is still in the barrel and high pressure exists. And kaboom, the case wall lets go. In my opinion, that is exactly what happened.

Now think about any straight blowback guns you have. I have a Hi Standard Supermatic Citation. I love to shoot different ammo, but some .22 rounds will leave me with little powder burns on my shooting hand. That is because the springs are calibrated to some form of target ammo, from 30+ years ago. Some ammo will extract before the bullet leaves the bore, spraying gas out the port (which of course is the entire top of the gun since there is no port - the slide simply hits the barrel to form the chamber). If you have shot a Marlin Camp Carbine or something similar, you have probably experienced the same thing - you get hot gasses out of the ejection port because the slide opened too soon.

In the case of a locked breech gun, that should generally not happen, which is one good reason that anything bigger than .380 is usually locked breech. You need that type of action to handle the higher pressure.

I don't know why the gun fired out of battery, I just know it did. The round may not have seated fully in the chamber for any number of reasons, but that is what happened. The round started to extract before the pressure dropped, and of course the case wall blew out at the weakest point. Gas always seeks and vents from the point of least resistance.

The theory is proven by the condition of the primer. It is not flattened. It was not pierced or cratered by the firing pin. It was not blown backwards. All those things are signs of excessive pressure. The primer shows none of those signs. He had trouble getting the empty case out because the 9mm is a tapered case. The front of the case was allowed to expand into too big of a space in the chamber, which plasters it onto the case walls, it was beyond the amount of expansion that it could come back from.

The slam fire was a pretty good theory, the only problem being that it would probably have been in battery when it occurred, and would not have caused the damage.

I had a Garand that would slamfire due to a burr on the bolt. It did it a few times. The gun went bang without pulling the trigger, but nothing was damaged, not even the cases.

So I have no doubt this is what happened. It all fits. He pulled the trigger to fire, there was no squib in the barrel, there was no slamfire, there was no overpressure. For some reason the gun did not go fully into battery, and fired in that condition.

The recoil spring could be the culprit, but so could dirt, or quite possible a tiny piece of brass from the previous round that stayed in the chamber.

[Alfonse]

I've run across some bad ammo lately. I had two out of 50 PMC .40 rounds that were too big to chamber in my PX4 and one round of WWB that had a 3/16 of an inch or so of the crimp bent back double. That round wouldn't chamber either.

Probably better than a snap cap for surprise practice of no boom drills.

[jimsea]

........this thread just gets better and better. Great theory, I like it.

Now the $64k dollar question is determining exactly why it did as your theory suggests.

[Bawanna]

It's a great theory but I'm not completely sold on it.

Has to be a combination of issues or the planets being aligned so to speak.

I have a K40 that when new would fire out of battery, only slightly out of battery but definitely not a good thing. It ended up going back for barrel peening and they replaced the barrel and slide no charge of course.

I never saw any bad signs carefully looking at the cases etc.

Take slightly out of battery, insert a possibly weak case, an mild overcharge etc and I might buy it full price.

[scosgt]

I have had many guns that did not always come completely into battery. .40 for some reason only comes in that flat point range ammo, and it does not always feed smoothly, especially in the Kahr.

But usually pulling the trigger does snap the gun fully into battery. In this case, Not. On my CM, holding slightly out of battery and pulling the trigger feels like it is pushing it into battery, so I am thinking something was wrong with the round or something was in the chamber.

[scosgt]

It's a great theory but I'm not completely sold on it.

Has to be a combination of issues or the planets being aligned so to speak.

I have a K40 that when new would fire out of battery, only slightly out of battery but definitely not a good thing. It ended up going back for barrel peening and they replaced the barrel and slide no charge of course.

I never saw any bad signs carefully looking at the cases etc.

Take slightly out of battery, insert a possibly weak case, an mild overcharge etc and I might buy it full price.

Depends on how much out of battery it is. As well, I assume yours is a .40
The case head is way more supported in the .40 based on photos here and my observations. Therefore, it would take less to have a thinner part of the case extracted too soon. Less distance, that is.

[scosgt]

9mm headspaces on the forward rim of the case. If that was distorted in some way, whether it hit the ramp on the way in, or the front of the mag or slide stop, or if it just came out of the loading machine that way, it would not have taken much to prevent it from fully seating. A little less, the gun goes into battery and this thread does not exist. A little more and the gun refuses to fire. OR, since the gun has not been fired since, maybe a mechanical problem with the gun prevented it from going fully into battery. I think the slide lock lever pin has to be round, the channel under the barrel has to be clear and not buggered up, the breech face has to be smooth and not have something stuck on it or the extractor. Not having the gun in hand we can not determine that, but I am convinced the damage to the case is totally consistent with premature extraction. And you can NOT cure that with a little blue pill.

[jimsea]

FWIW I took a shot of the 9 next to the .40 for comparison.....the .40 does seat a little further into the chamber.

http://i1278.photobucket.com/albums/y504/grouperjim/IMG_0340_zps9f8cec63.jpg
http://i1278.photobucket.com/albums/y504/grouperjim/IMG_0341_zpsd87eb9a3.jpg

[scosgt]

You really need to shoot a little more of a right angle to see how much of a difference there is.

[scosgt]

Never mind, the second picture did not load right away.

Yes, the .40 appears fully supported.

[jimsea]

After looking at the OP's blown casing again and the pics of the 9 and .40 barrels side by side with a round, I don't think the primer was struck prior to going into battery. The location of where the casing peeled back could have just as easily have happened to either of the barrels I have shown. The round in the .40 would have peeled forward but just not as far. My conclusion is that the casing was defective and the malfunction would have occurred regardless of how far the round was seated in the chamber of the barrel.

That's my two cents and I'm sticking to it. :D


http://i1278.photobucket.com/albums/y504/grouperjim/20130405_180451_2_zpsa70c6fcd.jpg

[jocko]

my 21 cents. supported or non supported. THAT casing was gonna blow

[MW surveyor]

Bet it felt something like this.

[jocko]

damn, surv: I had a nice post after seeing that photo about Wild Bill and Monica, but I decided I best pass on posting it. I think I'm on thin ice anyhow and it is 70- degrees here, if u get my point.

I am really trying to clean my act up but u damn guys just keep posting those dirty nasty ass photo's and I can't control myself..

[MW surveyor]

Hey, at least I'm not posting porn pictures of goats and sheep!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Gun Doctor]

Well, I just read your post about blowing out the pistol. As it is now the end of 2015,could you please update us on the condition of the pistol, kahr's customer service, etc. Inquiring minds wanna know! Thanks