Glock still have unsupported chambers?


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Fatelvis
July 15, 2012, 11:48 AM
Has Glock started using fully supported chambers, or are they still unsupported? Also, was it only 40S&Ws that had the problem with KBs? Thanks-

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NG VI
July 15, 2012, 12:09 PM
No pistol has a fully supported chamber, at least not any conventional service pistols. Glock increased the amount of chamber support in their .40 line something like fifteen years ago.


And any gun is likely to blow up if you fire again with a squib stuck in the barrel, or if you fire it with a double charge of propellant, not just Glocks. Remember who has the largest market share (Glock) and especially who has the largest share of pistols in the hands of new shooters, like at academies, where they will be shooting a good amount and may be less likely to notice a squib.

ku4hx
July 15, 2012, 12:48 PM
For some interesting "KB" data, search this sight for instances of kb. Lots of scary pictures of various KaBooms.

http://www.thegunzone.com/

Fatelvis
July 15, 2012, 01:02 PM
Thanks NG. I take it you're a fan of Glocks, lol. I am not a fan of them, and am not familiar with them, but a friend of mine asked me about this, and I wanted to answer him accurately.

DPris
July 15, 2012, 01:25 PM
When I went through the Glock armorer's course not long after the GEN 4 came out, I asked if the new guns had addressed that chamber issue & was told they had not.
The reason given was that it's part of retaining the feeding reliability.
This came from a travelling Glock instructor I've known for well over 25 years & he's a very knowledgeable ex-cop & longtime firearms instructor, former member of Jeff Cooper's outfit.

Like the Glocks or not, their chambers ARE more unsupported (or less fully supported) than many other brands.
And, they remain so.

And, it's not just the .40s.
Denis

mesinge2
July 15, 2012, 01:38 PM
While I am not a Glock fan (grip shape issue) and don't currently own one. IMO, the KB incidents are seen more often with Glocks for a couple of reasons. Simply, they are quite popular and there are probably more glock owners than M&P and XD owners as NG VI pointed out. Second, IIRC Glock states in the manual "don't use reloads". They say this because of the polygonal rifling and many reloads are made with lead. Polygonal rifling does not take leading well. Finally I think a lot of mall ninja types buy a Glock in 40 because it is 'tacticool' and they know nothing real about guns. So, they abuse it with double charged reloads, improper maintenance, improper ammo, etc.

http://i1210.photobucket.com/albums/cc401/mesinge2/Misc/my2cents.jpg

atomd
July 15, 2012, 01:47 PM
The newer Glock barrels have the same or very close to the same support as almost all the other popular .40 service pistols. Their chambers are a bit loosened up compared to some though. There's plenty of pictures online of a newer .40 glock barrel next to barrels made by sig, s&w, etc and you can't tell the difference by looking at them like you could with the older barrels. Some of the older ones had less support. When I put a gen 2 up next to a gen 4 I can see the difference and I can also see the difference in the ejected brass as well. Do I feel unsafe shooting reloads through the gen 2? Of course not.

Fatelvis
July 15, 2012, 04:00 PM
#1When I went through the Glock armorer's course not long after the GEN 4 came out, I asked if the new guns had addressed that chamber issue & was told they had not.
#2The newer Glock barrels have the same or very close to the same support as almost all the other popular .40 service pistols. Their chambers are a bit loosened up compared to some though. There's plenty of pictures online of a newer .40 glock barrel next to barrels made by sig, s&w, etc and you can't tell the difference by looking at them like you could with the older barrels.
#3Glock increased the amount of chamber support in their .40 line something like fifteen years ago.

Hmmm.....still wondering. Guess an email to Glock is in order. Thanks for the input Guys!

StrutStopper
July 15, 2012, 04:19 PM
I've heard you shouldn't shoot .40 reloads in a glock. I don't own one, but a friend of mine does. He heard the same thing when he bought the gun. I do reload .40 S&W, so when we go to the range I collect his brass. There is always a bulge at the bottom of the case near the head. I've heard this referred to as "glocked brass." When I run these thru the resizing die, they come out looking okay. I'm not sure I'd want to shoot them thru a gun that doesn't more fully support the case like the one that I assume caused the bulge in the first place. In a gun with a more fully supported chamber these reloads would be less likely to rupture near the case head. I'm not a Kaboom expert nor do I play one on TV, these are just my thoughts and observations. I'm sure if this is way off base someone more knowledgeable than I will chime in.

Gtscotty
July 15, 2012, 06:58 PM
I believe I had read several places that Glock had increased their chamber support in the late 90's or early 2000's, I'm not sure though. I do know that my G20 stock barrel has just as much chamber support as my Lone wolf barrel, which is supposed to have pretty good chamber support. The Glock chamber is definitely a little larger, and cases that have been fired in the standard chamber expand more than those fired in the LWD chamber. Lots of people reload Glock, most of them seem to use a factory crimp die with the innards removed to iron out minor "Glock smiles". If the Glock smiles are too large, the brass is pretty much shot.

hentown
July 15, 2012, 08:32 PM
For some interesting "KB" data, search this sight for instances of kb. Lots of scary pictures of various KaBooms.


The Gunzone is a terrible source for reliable information. They been caught in so many lies and misrepresentations that they should be banned from the internet!!:cool:

GLOOB
July 15, 2012, 09:12 PM
The newer Glock barrels have the same or very close to the same support as almost all the other popular .40 service pistols. Their chambers are a bit loosened up compared to some though. There's plenty of pictures online of a newer .40 glock barrel next to barrels made by sig, s&w, etc and you can't tell the difference by looking at them like you could with the older barrels. Some of the older ones had less support. When I put a gen 2 up next to a gen 4 I can see the difference and I can also see the difference in the ejected brass as well. Do I feel unsafe shooting reloads through the gen 2? Of course not.
+1.

This question comes up every few weeks, and the same misleading half-truths are posted over and over. It's to the point where I'm surprised useful information still manages to get posted once in awhile.

WardenWolf
July 15, 2012, 10:01 PM
The vast majority of kabooms come in .40 caliber Glocks. The problem is twofold. Part of it is Glock's fault, and part of it is due to a flaw with the .40 S&W round. The .40 S&W round is unusually vulnerable to bullet setback, which can dramatically increase chamber pressure if the bullet is pushed in even slightly. This hugely exacerbates the problems with the Glock's unsupported chamber, and makes case blowouts much more likely. As a result, I consider .40 caliber Glocks a Bad Idea. They're usually fine in almost any other caliber, but .40 should be a no-go.

WYOMan
July 15, 2012, 11:07 PM
Until someone can produce a chart that shows every centerfire firearm produced, the number of failures for each one, and a list of the causes of the failures, it's only conjecture to say that one manufacturer has had more than another. With the internet, news papers, and the 24 hour news, you would think that murders are higher now than ever before, but statics show they are down. Every time someone has any kind of problem with a firearm or ammunition, it's on you-tube, or someone's blog within minutes, and the stories fly about how people better stop using them. Does the show about the Remington 700 trigger ring any bells?

918v
July 15, 2012, 11:18 PM
The .40 S&W round is unusually vulnerable to bullet setback

No it's not.

Bullet setback is caused by incompetence.

Balrog
July 15, 2012, 11:32 PM
It is funny to me that its OK to spend money to have a 1911 chamber throated to make it more reliable, but when Glock does it, its a manufacturing defect.

I like 1911s and Glocks, and I like loose chambers in both.

Weevil
July 16, 2012, 12:15 AM
Yes Glock has increased the chamber support on the .40s in the last few years.

http://i112.photobucket.com/albums/n200/srebough/CaseSupport2-1.jpg


And yes it was only a documented issue with the .40s.

hentown
July 16, 2012, 07:32 AM
No it's not.

Bullet setback is caused by incompetence.

That's a truly absurd statement.

918v
July 16, 2012, 11:12 AM
How is it absurd? It it the gun that causes setback or the idiot who made the reload? use your head.

atomd
July 17, 2012, 07:54 AM
Setback is caused from improper of lack of crimp. True the design of the .40 cartridge might cause more movement of the bullet in the case when compared to say 9mm if both were assembled incorrectly....but it is still a problem with whomever crimped that round and not the gun. To say that you shouldn't shoot a reload through a Glock is silly. It's no different than any other .40 pistol out there as far as reloads go. The only debate is lead in a Glock and that's a whole different debate altogether. I have a .40 Glock that hasn't had one factory round though it....only reloads. It's only unsafe on the internet. Thankfully I shoot that pistol in real life instead.

Dan-O
July 17, 2012, 10:12 AM
If you are worried about a kb, get yourself a $100 aftermarket barrel that has much better chamber support like the one pictured in post #17. The only Glock barrels that have fully supported chambers are the 31, 32, and 33.

It was not a documented issue in only the .40's.

http://www.thefirearmblog.com/blog/2011/11/16/glock-20-10mm-auto-kaboom/

Jonah71
July 17, 2012, 12:53 PM
I've fired more rounds through my G 23 than I have any of my handguns. It's been my edc since I sold the old Kimber.I'll admit it took me a LOT of rounds to reach an acceptable level of accuracy. I don't reload or use reloads so I seriously doubt that I'll have any problems with the Glock in the future.

918v
July 17, 2012, 02:04 PM
Setback is caused from improper of lack of crimp.

I did a test. I sized a new case, minimally flared the case mouth using a conical plug that did not expand the case body (that way i had maximum case tension on the bullet), and seated the bullet.

The round experienced .002" to .003" of bullet setback per feeding cycle regardles of the crimp or lack thereof.

This is the best case scenario.

A worse scenario is using an undersized plated bullet, in a dirty case, after it has been expanded and flared excessively. I have some plated bullets that mike .001" undersize. They set back more than oversized bullets.

So,

One should pay attention to tolerance stacking in order to avoid mishaps.

I suggest the following:

Sort your brass (case wall thickness and the resulting case tension on the bullet varies between brands).
Don't lube the brass by shaking it in a bag (lube will get inside the case and interfere with bullet retention).
Flare the case mouth minimally using a Lee Universal Expander die (it does not expand the case body). This will ensure maximum case tension on the bullet.
Use quality bullets, correctly sized or slightly oversized (using .356" bullets in a 9mm will produce less bullet setback than .354" bullets).
Use clean brass, tumbled in stainless media to remove carbon from inside of the case (a clean case wall will hold the bullet better than a carbon fouled one -carbon acts as a lubricant).
Crimp only to remove the bell and no more. Crimp does not stop bullet setback.

atomd
July 17, 2012, 07:59 PM
The round experienced .002" to .003" of bullet setback per feeding cycle regardles of the crimp or lack thereof.


That's interesting. I did the same test and my calipers don't read any difference at all in the round. I tried chambering multiple rounds and also tried whacking the rounds on top of my work bench and re-measuring. Same size. These rounds were crimped using the lee fcd.

918v
July 17, 2012, 09:05 PM
Whacking the round on top of the bench will not set the bullet back. What gun were you cycling them through? If your gun feeds them straight into the chamber that's one thing. On some guns (1911) the round has to glance off the feedramp and then off the roof of the chamber. Those platforms induce more setback than others with a more gradual feed angle.

atomd
July 17, 2012, 09:17 PM
G22

918v
July 17, 2012, 10:35 PM
You have an amazing talent.

atomd
July 18, 2012, 07:59 AM
A lot of the bullet setback stuff you see is people rechambering the same round over and over again (most of what I see they have done at least 10-50 times). After one time (this is not a duty weapon so I won't be rechambering the same round over and over) the calipers I used...not the most accurate calipers out there but accurate enough to see a big difference...didn't show enough difference to accurately say it was set back at all. Even if it were set back, it would not be enough to bring it out of spec or to anything remotely dangerous. After doing a quick search, there seems to be plenty of other people that don't get setback after one or 2 chamberings. Some of the tests I read showed a slight setback after a few chamberings and then significant setback after more. Also, the ammo used was all different and some people had different measurements using the same gun with different ammo. I'll have to do more tests and try to be more accurate to really see I guess. I'm not concerned though.

ny32182
July 18, 2012, 09:19 AM
This is one of those internet echo chamber things that is absolutely ridiculous.

Less internet babbling and more shooting is the order of the day here. Under those conditions you will find that there is not really any problem here as long as you are not a complete idiot.

1) If you reload, make sure your neck tension is good. Proper sizing of the case, and proper size of the bullet are the key factors here. Crimp has little to nothing to do with it. This is not unique to the .40 or the Glock.

2) Don't shoot a billion lead bullets through the Glock factory barrel between cleanings. This is not unique to the .40. This is not unique to the Glock.

3) Don't chamber the same round a billion times before shooting it. This is not unique to the .40 or the Glock.

4) Small variations in OAL will not be the root cause of a KB. .001" is not the deciding factor in your KB. If it happens to be the straw that breaks the camel's back, you have probably done one or more other things horribly wrong to get to that point in the first place. This is not unique to the .40 or the Glock.

Millions of police around the country use the .40 Glock, which happens to be the most popular police pistol in the country. Most individual police officers are not exceptionally great when it comes to shooting or maintaining their gun. Yet every day, millions of police officers manage to not blow up their .40 Glock. If they can do it, you can do it! Go get 'em!!

RAINS
July 18, 2012, 07:39 PM
Yarp. .40 Glocks are harder on brass than some other pistols. I don't pick up my glock brass 40 or 45. You can just look at the brass and see that's it's budged out more than say a 1911 or Sig. So just don't shoot reloads or lead or plated ammo. It's not a problem with 9mm glocks though. Some might dispute that .45acp Glocks are hard on brass but I trust my eyes.

bds
July 19, 2012, 06:13 PM
2) Don't shoot a billion lead bullets through the Glock factory barrel between cleanings ... This is not unique to the Glock.
IMHO, it is more of an issue with rifling unique to Glock.

http://www.thehighroad.org/attachment.php?attachmentid=163255&stc=1&d=1335152658

http://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/Polygonal_vs_normal_rifling.svg/493px-Polygonal_vs_normal_rifling.svg.png

Unlike true polygonal rifled barrel (http://en.wikipedia.org/wiki/Polygonal_rifling) on the right, Glock barrels are round with six (hexagonal) rifling (see above picture). IME, the trouble with shooting lead loads is that Glock barrels have longer leade (space bullet jumps from the case neck/chamber to the start of rifling) and very smooth and rounded start of rifling. These factors allow more high pressure powder ignition gas to leak around the bullet resulting in gas cutting and blow more liquefied lube off the bullet's bearing surface down the barrel which results in more fouling deposit near the chamber end of the barrel and more crusty fouling deposit along the rifling - http://www.lasc.us/FryxellLubeCastBullets.htm

Below is a picture of a factory Glock 17 barrel with about 100 rounds of lead loads shot through and you can see the crusty fouling deposit along the rifling. If I continue to shoot, I would essentially be left with a smooth bore barrel with reduced diameter, which may significantly increase the chamber pressure. The comparison picture below is a conventional land/groove rifled Lone Wolf barrel with 350+ rounds of lead loads shot through and all you see is residual lube smearing left on the rifling.

http://www.thehighroad.org/attachment.php?attachmentid=151380&stc=1&d=1319341855
http://www.thehighroad.org/attachment.php?attachmentid=162418&stc=1&d=1333939386

I do shoot lead loads in factory Glock barrels, but inspect the barrel every 200-300 rounds and clean as necessary (Hoppes #9 solvent and old bore brush wrapped with copper scrubber strands like Chore Boy does a great job - few strokes and barrel is clean).

Waywatcher
July 19, 2012, 06:40 PM
I reload for my Glock 23 and was super paranoid and careful when I first started.

My reloads are superior to factory ammo in every measurable way; even after chambering a single reload 40 times I had setback of 0.002", and I get extreme spreads in the teens and standard deviations in the single digits--with Power Pistol powder; and just 0.2 grains above the starting load I matched factory velocity (and stopped working up).

quartermaster
September 30, 2012, 07:37 AM
Sorry to jump in this thread so late, but I was going to start a thread addresing this question. What exactly is meant by a Glock unsupported case? Is it that the chamber is shorter than the case or is it that the back of the chamber is oversized a bit to improve feeding?

I am not a big handgun shooter, although I should find the time to practice more.

QM

WinThePennant
September 30, 2012, 08:51 AM
This is an issue that I wish would just go away.

Whenever I hear about people having trouble, it's always with a .40 or reloads or a combination of the two.

If you're worried about it, then shoot 9mm.

The .40 is the most overrated round ever, and it seems to cause its unfair share of problems in all guns (Glock, Ruger, S&W, etc.).

High pressure rounds are nothing but trouble. Shoot either a 9mm or a .45 and be done with it.

Certaindeaf
September 30, 2012, 09:34 AM
9mm is not a low pressure round. It's very close to .40 and probably higher given the +P renderings.

WinThePennant
September 30, 2012, 10:38 AM
You are right, but it's easier to overpressure the .40. Especially with the 180 grain round.

Ar180shooter
September 30, 2012, 01:31 PM
thousands of rounds through my G22 and it hasn't mangled my face yet, and it won't, as long as I avoid sketchy ammunition.

The problem isn't with the Glock, it's with the idiots who buy Glock. (Not that you're an idiot for buying a Glock, but I don't want to take that card off the table. :D)

Deaf Smith
September 30, 2012, 01:35 PM
KBs in Glocks are due to:

1. Glocks can fire out of battery. That is a out-of-speck round that is to long will still chamber and fire. I've had two kabooms in Glocks (17 and 26) due to this. Not a real fault of the gun cause alot of others can still fire when they are just a bit out of battery.

2. Unsupported chambers. This relates to #1 above. With a slight out-of-battery condition and severely unsupported chamber you can have the case fail.

3. Lead buildup in Glock polygon barrels (with the increase in pressure.) Any polygon barrel can have this happen.

4. Bullet setback. Mainly occurs if the slugs are so long there is no space in the case and if the bullet is setback the pressures rise (as they do in #3 above.) I find the lighter 165/155s are best to avoid this in the .40 S&W.

5. Weak case construction. This happened in both the .40 S&W and .357 Sig at first. Thin cases & high pressures lead to case failure. Add bullet setback, out-of-speck cases, and lead buildup and my my, I wonder how ANY pistol could not blow up!

Oh, and I've handled several revolvers that have been blow to bits due to bad loads. Top straps, charmers, and such were just blown off. Also seen .38 Super 1911s have case failure (known as 'superface') due to overloading for IPSC Major.

Overall, if you use quality JACKETED ammo in a Glock you will be fine. My carry Glocks are all subcompacts. 26,.27, and 33 (and right now the 27 is in play due to winter coming.)

I do not worry about KBs in it or any of my Glocks. But then I avoid gun show reloads and other such stuff. I reload using only Winchester, Remington, Federal, and S&B cases and throw away the rest.

Deaf

HOOfan_1
September 30, 2012, 01:57 PM
I reload using only Winchester, Remington, Federal, and S&B cases and throw away the rest.


I'm using Blazer cases in both my .40S&W FNP and my Glock 19. They are holding up just as well as Winchester, R-P and FC

Guillermo
September 30, 2012, 05:25 PM
Weevil

thank you for the picture

That certainly clears things up

quartermaster
October 1, 2012, 06:30 AM
What is meant by an unsupported case?

HOOfan_1
October 1, 2012, 08:31 AM
What is meant by an unsupported case?

Unsupported CHAMBER. Look at Weevil's post on the first page, you will see that the feed ramp is farther forward on some, which means the cartridge is not fully enclosed on some of them. Obviously, that means the cartridge case is what is holding in the pressure at that point when the round is fired.

hentown
October 1, 2012, 11:14 AM
For some interesting "KB" data, search this sight for instances of kb. Lots of scary pictures of various KaBooms.

[url]http://www.thegunzone.com/][/url

That would be the last source I"d ever refer anybody to. Mostly male bovine excrement, thrown in with a good dose of prevarication. :rolleyes:

HKGuns
October 1, 2012, 11:39 AM
I "heard" the moon is made of cream cheese!

quartermaster
October 1, 2012, 08:43 PM
Thanks HOOfan 1

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