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A Brief Primer on KB's

140K views 377 replies 125 participants last post by  Colt6920 
#1 ·
The purpose of this thread isn't to be contentious relative to this frequently misunderstood subject, but rather to offer a little rational thought and a few facts. (Particularly for the newbies who might have been influenced by the Internet Ignorami)

First, whether a pistol, eg., Glock, has a supported or unsupported chamber is generally irrelevant to the subject of KB's. While an unsupported chamber might contribute to a case failure, a case failure does not constitute a KB.

So, what's a KB, then? Well, to me, a KB results in catastrophic failure of either a pistol's barrel or slide, or both. A case failure will probably result in a damaged mag, mag release, trigger assembly, maybe even a damaged frame. (or, in the case of 1911's, shattered grips)

In order for a case failure @ 6 o'clock to cause a KB, one would have to accept the premise that such a failure would cause dramatic increases in chamber pressure. Does anybody really believe that a RELEASE of pressure @ 6 o'clock will increase chamber pressure? Ever take h.s. physics? If not, or if you failed h.s. physics, then perhaps you should try writing for a gunrag or sponsoring a specious internet site.

Let's use an analogy for the purposes of demonstrating the silliness of blaming lack of case support for KB's. Ever fill up an air tank? Ever wonder what happens to a steam boiler or water heater when tank pressures exceed the tanks' pressure maximums? Well, if the tank has a pop-off valve or other method of releasing pressure, not much happens. With no such relief mechanism, a lot happens, catastrophically. Get the analogy with pistol chambers? If you don't, then, well, good luck with your life.

Photos of blown-up pistols on websites prove nothing, nor make any statements about the design features of that particular blown-up pistol. The picture might just reflect the statistical quality control anomaly of a factory round, or it might indicate an overcharged reload. The posting of a picture or anecdote on the internet doesn't give one any facts at all regarding KB's. (Even if the photos are of G21's blown up by police officers)

There are, I believe, over 2 million Glocks alive and well worldwide. If, as is claimed by the uninformed, Glock's design causes Glocks to randomly explode, then we'd certainly be hearing of more than just a few random cases of exploded Glocks on the internet. Nope, if design flaws were the problem, we'd be seeing tens of thousands of blown-up Glocks, government-demanded recalls, and not just the few "examples" that are posted here-and-there.

Now for my own anecdote. I've fired somewhere in the vicinity of 150,000 rounds of my reloads through my Glocks, mostly through G21's. Matt, of CGR, and others, have fired many times more of their reloads through their Glocks than I have through mine. I reload my .45ACP's until the necks split. I've never even had a 6 o'clock case failure, let alone a KB, using a factory Glock barrel.

I did experience a KB with my original G21 (see photo), using an aftermarket barrel, powder that was too fast, bullet that was too heavy, and a little of my own carelessness mixed in. Clearly had a feedramp bullet setback, with the expected KB. Please note that the case is split down its entire length. If this had been a 6 o'clock blowout, the case would only have failed @ 6 o'clock.

Glocks are among the safest pistols in use today. They are not subject to an abnormal risk of KB. If you overcharge, or, especially, doublecharge a round or use an overcharged or doublecharged factory round, your pistol, regardless of manufacturer, will probably KB.

It's as simple as that.
 
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#327 ·
Believe what you want...

http://www.thegunzone.com/glock/g19-kb.html

Both the Model 19 and Model 34 have had Kabooms. The Model 19 with reloads and the Model 34 with factory ammo.

http://www.thegunzone.com/glock/g19_topless.html
The last of those links has nothing to do with "Kabooms!" It is about a broken slide lock lever spring in a G19. I've seen that with G19s which had the old wasp-waist spring. I've alos experienced three failures of that spring in my old G30 (which did not have wasp-waist springs; the failures, all of which happened early on in my experience with the G30 and are likely a result of sloppy field-stripping/reassembly of the weapon). If that spring breaks, the slide does NOT depart from the frame unless and until you pull the trigger on an empty chamber! As long as you insert a loaded magazine every time the slide locks back you can keep shooting until the cows come home!
 
#330 ·
There is a picture of a KB case to the right of the article. The primer strike seems to be high. This could be a normal or it could be an indication of out of battery KB. The case failed at the 4 o'clock position, when the most common area of failure is the 6 o'clock, again out of battery indication.
Just a thought.
According to the Glock people out of battery fire can't/doesn't happen. You need a stronger dose of Kool Aid :supergrin:
 
#331 ·
I had never heard of any make of semi-auto pistol that had cartridge cases blowing out at the 6 O'clock position, until the 40 S&W and Glocks for it, was in common use. It also happened with Glock 45 ACP but I never have seen such a failure, in a 10 mm Glock.

I think the 40 S&W is really a poor design and deserves some of the credit for KBs. The Glock chambers do seem to have less chamber support, at 6 O'clock, than other makers guns. I haven't had any problem with any of my Glock pistols.

Anyone can define a KB, anyway they perceive it, but I consider I have a KB, if hot, high pressure gas comes out of the gun anyplace, than the muzzle. Glocks are not actually "perfect" but Glock won't ever admit it. They clean up any problems and try to keep anyone from knowing about them. I have heard of more than one LE agency replacing their new Glock 40 S&W pistols with a 9mm version. Why would they do that, if there's no problem?

Modern guns are fired many more rounds, over their lifetime, than guns up to about 1950. I have known several people that probably never owned 2 full boxes of ammo, for their guns. They just plain didn't have the money for that and I mean a box of 22rf. I have bought 12 gauge buckshot by the 5 each out of a broken box of 25, at hardware stores.
 
#332 ·
I had never heard of any make of semi-auto pistol that had cartridge cases blowing out at the 6 O'clock position, until the 40 S&W and Glocks for it, was in common use. It also happened with Glock 45 ACP but I never have seen such a failure, in a 10 mm Glock.

I think the 40 S&W is really a poor design and deserves some of the credit for KBs. The Glock chambers do seem to have less chamber support, at 6 O'clock, than other makers guns. I haven't had any problem with any of my Glock pistols.

Anyone can define a KB, anyway they perceive it, but I consider I have a KB, if hot, high pressure gas comes out of the gun anyplace, than the muzzle. Glocks are not actually "perfect" but Glock won't ever admit it. They clean up any problems and try to keep anyone from knowing about them. I have heard of more than one LE agency replacing their new Glock 40 S&W pistols with a 9mm version. Why would they do that, if there's no problem?

Modern guns are fired many more rounds, over their lifetime, than guns up to about 1950. I have known several people that probably never owned 2 full boxes of ammo, for their guns. They just plain didn't have the money for that and I mean a box of 22rf. I have bought 12 gauge buckshot by the 5 each out of a broken box of 25, at hardware stores.
Well said! :thumbsup:
 
#334 ·
WalterGa definition of a KB.
So, what's a KB, then? Well, to me, a KB results in catastrophic failure of either a pistol's barrel or slide, or both. A case failure will probably result in a damaged mag, mag release, trigger assembly, maybe even a damaged frame. (or, in the case of 1911's, shattered grips)

AustinTx definition of a KB.
Anyone can define a KB, anyway they perceive it, but I consider I have a KB, if hot, high pressure gas comes out of the gun anyplace, than the muzzle.


I don't want to have either kind, of KB or whatever you care to call it.
 
#337 ·
At the end of the day and objectively speaking, KBs are really about bad ammo/reloads and/or lack of proper maintenance.

By the way, re fully supported barrels, well, I recently acquired a barsto barrel for my G21SF and while testing out some loads I recently made, I came across two loads that was obviously overcharged (got mixed up with some old/discarded loads), the same having registered a 1200 fps and 1100++ fps respectively. Given my past experiences narrated in the first page of this thread, I do believe that if I then was using my original/factory barrel, I would have experienced another KB. However, and to my great satisfaction, instead of the shell blowing up, what I experienced was but a gigantic "recoil" which actually broke my two handed grip, the gun jumping towards the right and back. Hence, with respect to supported and unsupported barrels, I do believe that there really is a difference especially with respect to the barrel chamber's "tightness" :)
 
#338 ·
At the end of the day and objectively speaking, KBs are really about bad ammo/reloads and/or lack of proper maintenance.
That's you opinion and you are certainly entitled to it. But I sure don't agree. There are just too many instances of the Glock .40S&W Kabooming using a wide variety of ammo for it to be bad ammo. And I don't get the "lack of proper maintenance" comment at all. Glocks are famous for needing minimal maintenance. Maybe if you dunked the barrel in oil and tried to shoot it, you could use that excuse. Otherwise, I don't buy it.
 
#339 · (Edited)
So, what's a KB, then? Well, to me, a KB results in catastrophic failure of either a pistol's barrel or slide, or both.
I could not agree more, but we need to hear from a broad consensus of Glock owners who have had KB's in order to get a more universal opinion, not just yours.
Although many point their finger at the .40, I'm sure KB's have occured in other Glock calibers, and they have. It would be interesting to hear what experiences others have had regarding KB's, and the calibers involved.
 
#340 ·
That's you opinion and you are certainly entitled to it. But I sure don't agree. There are just too many instances of the Glock .40S&W Kabooming using a wide variety of ammo for it to be bad ammo. And I don't get the "lack of proper maintenance" comment at all. Glocks are famous for needing minimal maintenance. Maybe if you dunked the barrel in oil and tried to shoot it, you could use that excuse. Otherwise, I don't buy it.
I think the lack of maintenance means to clean the lead out of the barrel.
To much build up can and will cause a failure and increase in pressure that will vent from everywhere other than the barrel.[read this on the first page].
Pistol rounds chamber on the edge of the brass case. Lead buildup may not allow the case to seat fully but Glocks are not suppose to fire out of battery.
I choose to keep mine clean especially after shooting lots of lead.
There are those of us that keep our cars and trucks sparkling clean even
when we drive them every day. The rest of us keep our guns clean but might not shoot them once a month!
 
#341 ·
I think the lack of maintenance means to clean the lead out of the barrel.
To much build up can and will cause a failure and increase in pressure that will vent from everywhere other than the barrel.[read this on the first page].
Pistol rounds chamber on the edge of the brass case. Lead buildup may not allow the case to seat fully but Glocks are not suppose to fire out of battery.
I choose to keep mine clean especially after shooting lots of lead.
There are those of us that keep our cars and trucks sparkling clean even
when we drive them every day. The rest of us keep our guns clean but might not shoot them once a month!
Many of the Kabooms were experienced with jacketed ammo. No lead is involved there. The Glock was designed for military purposes using FMJ bullets. They can shoot many thousands of them with NO maintenance.
I NEVER use lead for any of my semi-autos. To do so means you take your chances and suffer the consequences. The tradeoff of cheaper ammo is risk of destroying your gun. Something I won't chance.
 
#342 ·
Okay, so it (very rarely) happens with .40 cal. How about with .45GAP? Personally, I LIKE the availability and price of .40- over .45GAP, anyway- but I'll bite on the kB issue. Is it worth the hassle of going to a different caliber? Asking because I'm partial to the compact Glock sizes, they just fit my hand best and do everything I need well. And as good as the 9mm is, I have to compensate a little; I'm a small guy with a small package. I need a bigger bullet.http://glocktalk.com/forums/images/smilies/embarass .gif

BTW, anybody want to trade a new or like-new 23 for my like-new 29?
 
#344 · (Edited)
I had to research this KB years ago and found, the officer was using reloads that had a larger charge then recommended.Any gun today can KB, with the right mix of powder, double-charge etc.
 

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#349 ·
I had a "case failure" in two guns; one was a Colt 1911 & the other a SIG 220. The grips were shattered on the Colt & the remaining round in the magazine were jammed down. The mag was ruined but the gun was ok. A similar event happened with the SIG except that the gun was ruined because the aluminum receiver bulged and split open. Those events were KB's as far as I'm concerned dispite the OP's contention otherwise.
 
#350 · (Edited)
You know, I've waited for more than six years to answer this post. I thought to answer it when it first came out; but, at the time, I was fully aware that to do so would have caused an emotional, 'firestorm' among impassioned owner/admirers.

So, I very deliberately decided to remain silent. Now I'm thinking that if I owe Glock Talk one last post, this is it. So, here goes:

'First, whether a pistol, eg., (SIC) Glock, has a supported or unsupported chamber is generally irrelevant to the subject of KB's. (SIC) While an unsupported chamber might contribute to a case failure, a case failure does not constitute a KB. (SIC)'
Incorrect. If supported or unsupported chambers did not contribute to Glock kB!'s then a steady progression of tighter and tighter chamber mouths would not be evident throughout subsequent generations of Glock pistols.

Incorrect, again. A case failure, if it is significant enough, can certainly cause a kB!.

'So, what's a KB, (SIC) then? Well, to me, a KB (SIC) results in catastrophic failure of either a pistol's barrel or slide, or both. A case failure will probably result in a damaged mag, mag release, trigger assembly, maybe even a damaged frame. (or, in the case of 1911's, shattered grips)'
Incorrect. The key phrase here is, 'to me'. It relegates everything that follows to a subjective context. Furthermore, the originator of the expression, 'kaBoom!' would (I am sure.) never agree to such a narrow definition.

'In order for a case failure @ 6 o'clock to cause a KB, (SIC) one would have to accept the premise that such a failure would cause dramatic increases in chamber pressure. Does anybody really believe that a RELEASE of pressure @ 6 o'clock will increase chamber pressure? Ever take h.s. physics? If not, or if you failed h.s. physics, then perhaps you should try writing for a gunrag (SIC) or sponsoring a specious internet site.'
Incorrect. This remark is contrived in such a way as to be a convoluted slam at Dean Speir. ANY sudden release of case pressure, at any location other than the case mouth, can - I am certain - cause a kaBoom! event.

'Let's use an analogy for the purposes of demonstrating the silliness of blaming lack of case support for KB's. (SIC) Ever fill up an air tank? Ever wonder what happens to a steam boiler or water heater when tank pressures exceed the tanks' pressure maximums? Well, if the tank has a pop-off valve or other method of releasing pressure, not much happens. With no such relief mechanism, a lot happens, catastrophically. Get the analogy with pistol chambers? If you don't, then, well, good luck with your life.'
Incorrect. The above is a classic example of an illogical non-sequitur. (I prefer to call specious logic like this, 'mental diarrhea'.)

'Photos of blown-up pistols on websites prove nothing, nor make any statements about the design features of that particular blown-up pistol. The picture might just reflect the statistical quality control anomaly of a factory round, or it might indicate an overcharged reload. The posting of a picture or anecdote on the internet doesn't give one any facts at all regarding KB's. (SIC) (Even if the photos are of G21's blown up by police officers)'
This premise is arguable; and, an opposite situation or opinion would be, equally, as valid. Neither premise is capable of producing a preponderance of irrefutable evidence - Period.

'There are, I believe, over 2 million Glocks alive and well worldwide. If, as is claimed by the uninformed, Glock's design causes Glocks to randomly explode, then we'd certainly be hearing of more than just a few random cases of exploded Glocks on the internet. Nope, if design flaws were the problem, we'd be seeing tens of thousands of blown-up Glocks, government-demanded recalls, and not just the few "examples" that are posted here-and-there.'
Incorrect. Glocks kaBoom! more often, and for more different reasons, than any other pistol. From someone who demands a preponderance of evidence in order to prevail, this laissez-faire acceptance of what amounts to little more than unsubstantiated technical innuendo is rather surprising - if not prejudicial.

In my experience: If Glock pistols are anything, at all, they are, 'works in progress'. Consequently, one of Glock's outstanding physical characteristics is, for lack of a better word, 'inconsistency'.

Some Glock pistols do this; and other Glock pistols do that. Besides, Glock, GmbH has quietly settled so many lawsuits that it is extremely difficult to know just how broad this problem actually is?

It is, however, 'a large number' that has clearly been litigated rather than enforced by any government fiat. Lucky for Glock, GmbH - Huh!)

'Now for my own anecdote. I've fired somewhere in the vicinity of 150,000 rounds of my reloads through my Glocks, mostly through G21's. Matt, of CGR, and others, have fired many times more of their reloads through their Glocks than I have through mine. I reload my .45ACP's until the necks split. I've never even had a 6 o'clock case failure, let alone a KB, using a factory Glock barrel.'
So what! One of the first things I ever learned about my brand new G-21's - You know, the Glock pistols with the sporadically defective #4256 trigger bars - was that, if you wanted to prevent them from blowing up in your hand, they had to be very carefully custom-tuned.

In fact, in order to continue safely running my early third generation Glock 21's, over a 3 or 4 year period-of-time, I was forced to become a knowledgeable (and still uncertified) Glock armorer. (Just like the author of the commentary I'm presently critiquing.)

When it came to successfully running one of my Model 21's, knowing how to custom-tune them made all the difference between safe and unsafe operation. By the way, my own round count is, also, in the tens of thousands. Again, so what!

'I did experience a KB (SIC) with my original G21 (see photo), using an aftermarket barrel, powder that was too fast, bullet that was too heavy, and a little of my own carelessness mixed in. Clearly had a feedramp (SIC) bullet setback, with the expected KB. (SIC) Please note that the case is split down its entire length. If this had been a 6 o'clock blowout, the case would only have failed @ 6 o'clock.'
And, the point is ...... ? This colorful personal anecdote is strictly an emotional appeal that validates absolutely nothing.

'Glocks are among the safest pistols in use today. They are not subject to an abnormal risk of KB. (SIC) If you overcharge, or, especially, doublecharge (SIC) a round or use an overcharged or doublecharged (SIC) factory round, your pistol, regardless of manufacturer, will probably KB. (SIC) It's as simple as that.'
No, it's not, 'as simple' as that. When the author wrote his original article, he was completely ignorant about a unique operating characteristic of all polymer frame pistols: One subsequently identified by Glock, GmbH as, 'frame harmonics'.

'Frame harmonics' is a polymer pistol frame operating phenomenon that - to the best of my knowledge - I am the first member of this board to, either, mention or post any suspicions about.

At the time, the reaction of the general membership was, 'dead silence'; and, it took the Glock factory, itself, more than another year before they were finally ready to publicly admit this unique operating characteristic of polymer frame pistols.

As already stated: Glock's polymer frame pistols are, indeed, 'works in progress'. As a group, the third generation pistols - and especially the later serial number third generation pistols - are, without question, the most trouble free polymer pistols in the world.

Still, and again as I've already stated, if Glock's model lineup of polymer pistols has two outstanding physical characteristics, those characteristics would be extreme reliability AND inconsistency.

The long and the short of things is that - regardless of whatever the model number may be - if you have a Glock pistol that works, keep it.

If, however, you have a Glock pistol that does not work then attribute it to a, 'learning curve' - Either: your own, or someone else's. (It's, kind 'a, like being part of a great industrial experiment - Isn't it!)
 
#351 · (Edited)
You know, I've waited for more than six years to answer this post. I thought to answer it when it first came out; but, at the time, I was fully aware that to do so would have caused an emotional, 'firestorm' among impassioned owner/admirers.


............interesting monologue/dissertation snipped..............
Interesting.

I have a very early 3rd generation G19 (before the third pin), and a very recent G23. I have trusted, and will continue to trust, my life to either of them any time I leave my home state. Until such time as one of them blows one of my fingers off. If that happens, I will whine, cry, and feel violated. And move to a lesser defensive pistol at such time.
 
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