Glock 21 unsupported chamber

Noreaster · October 23, 2013, 09:07 PM

Just took a Glock Instructor course and a couple of the guys were shooting G21s. With all I've heard about them I was actually looking over my shoulder half the time while firing next to them on the range, would the G21 go kaboom! After the second day I was picking up their brass and looking for the bulge but I couldn't find any. The course was grueling and I was sick of shooting by the end of it. I know I fired over a 1,000 rds so I'm sure the G21 guys did as well. So, based on my experience, do the Gen 4 G21s have better case support or is the whole KB thing really ammo related and not the gun?

Tactical Jackalope · October 23, 2013, 09:12 PM

I personally think it's ammo related when it comes to the .45ACP in Glock.

Now with the .40S&W it's definitely an unsupported chamber issue. Primarily in the older models.

jimbob86 · October 23, 2013, 09:25 PM

The .45ACP does not operate at high enough pressure (or is not supposed to- folks running it @ Ludicrous Speed may experience "issues" ..... ) to bulge cases in "unsupported" chambers ....

All the KB's I've been aware of locally were in Glocks chambered in .40 S&W, and involved handloads. One was with a mix of lead and jacketed bullets in a stock (polygonal rifled) barrel and the other was in an aftermarket barrel with conventional rifling using bulk jacketed bullets ..... both guys were using very fast pistol powder (one was Titegroup, don't remember the other) in an effort to cut costs (fast powder gives more charges per pound purchased) ......

RBid · October 23, 2013, 10:53 PM

I think the important thing to understand about .40 and .45 Glocks is that the gubmint buys them for Federal agencies and LE departments because politicians are cop killers who want to wipe out the law through kabooms. These firearms are ticking time bombs, which is why every gun forum is littered with "my cousin was a Navy SEAL , until Glock killed him!" threads.

Me? I'm suicidal, so I put as many rounds as possible through my Glock 23 Gen 4. Sooner or later, it'll explode, and I'll get to go see Grandpa Ed and play poker with Elvis and Biggie.

If you value life, don't buy these pistols. They'll kill your face right off.

iraiam · October 23, 2013, 11:11 PM

I own both a Gen3 and 4 G21. I have never been able to run them at high enough pressure to even start to see bulging cases, and I have tried. The recoil gets to be noticeably slide slamming way before the pressure gets high enough to bulge a 45 auto case.

I generally use HS-6 and Power Pistol for 45 auto loads.

sig1 · October 24, 2013, 07:07 AM

Quote:

Originally Posted by RBid

I think the important thing to understand about .40 and .45 Glocks is that the gubmint buys them for Federal agencies and LE departments because politicians are cop killers who want to wipe out the law through kabooms. These firearms are ticking time bombs, which is why every gun forum is littered with "my cousin was a Navy SEAL , until Glock killed him!" threads.

Me? I'm suicidal, so I put as many rounds as possible through my Glock 23 Gen 4. Sooner or later, it'll explode, and I'll get to go see Grandpa Ed and play poker with Elvis and Biggie.

If you value life, don't buy these pistols. They'll kill your face right off.

Lol, I'm trying to blow my face off to, haven't been able to do it yet, still time thou.

bt380 · October 24, 2013, 08:09 AM

I'm no gunsmith, but stating the Glock 21 has the problem because of its unsupported chamber, may not be inclusive enough. I have a one year old Beretta Storm PX4 in full sized 40 cal and its chamber is also unsupported. To determine if your 40 cal has an unsupported chamber, when cleaning, and the barrel is out, do the plunk test (dropping a cartridge in it), and check to see if the shell is slightly exposed or not. If exposed, your 40 cal chamber is unsupported. Does that mean your gun should not use the max loads? I have no idea, I'm not a gunsmith and have not read about other pistols having this issue. Perhaps others could speak to this to clarify if this is any 40 cal pistol or what ever?

thedudeabides · October 24, 2013, 08:14 AM

45 ACP doesn't need a lot of chamber support due to its very low pressures, just look at the chambers in many 1911s. Even when using +P ammo. Now if you want to try 45 Super and test your theory, you're on your own.

I think that Glock manufactured a batch of 21s a few years back that had atrocious chamber support (even for 45 ACP), fixed and buried the issue, and went on with their lives. Furthermore, I think it's based on the overall "loose fit" of Glocks that sacrifice fit and accuracy for ultimate reliability to feed and fire all ammo types.

RBid · October 24, 2013, 01:00 PM

Quote:

Originally Posted by thedudeabides

45 ACP doesn't need a lot of chamber support due to its very low pressures, just look at the chambers in many 1911s. Even when using +P ammo. Now if you want to try 45 Super and test your theory, you're on your own.

I think that Glock manufactured a batch of 21s a few years back that had atrocious chamber support (even for 45 ACP), fixed and buried the issue, and went on with their lives. Furthermore, I think it's based on the overall "loose fit" of Glocks that sacrifice fit and accuracy for ultimate reliability to feed and fire all ammo types.

It's true. High pressure rounds like 9, .40, 10, and .357 Sig always blow Glocks up, and they're inaccurate. That's why hostage rescue groups like CAG and FBI HRT would NEVER use a Glock... especially in .40...

SPEMack618 · October 24, 2013, 01:12 PM

I swear ever since I got back from the A-Stan, my sister says I'm different. I didn't realize I was acting suicidal until the internet told me so in regards to my Glock 21.

I've shot all kinds of loads, from Wolf range fodder all the way up to Remington and Hornady +P personal defense loads.

And with my Gen 3 at that.

Now, I'm not exactly a raving Glock fanboy, but when a company that generates most of it's revenue from selling to police forces (as Glock Inc. does) publicy states that a major metropolitan force (Portland PD) is a difficult customer in regards to their "Glock Kabooms" I sorta tend to think that maybe it ain't the gun. Maybe it is Officer Bubba and his "man-stopping" hand loads.

RBid · October 24, 2013, 03:47 PM

Quote:

Originally Posted by SPEMack618

I swear ever since I got back from the A-Stan, my sister says I'm different. I didn't realize I was acting suicidal until the internet told me so in regards to my Glock 21.

I've shot all kinds of loads, from Wolf range fodder all the way up to Remington and Hornady +P personal defense loads.

And with my Gen 3 at that.

Now, I'm not exactly a raving Glock fanboy, but when a company that generates most of it's revenue from selling to police forces (as Glock Inc. does) publicy states that a major metropolitan force (Portland PD) is a difficult customer in regards to their "Glock Kabooms" I sorta tend to think that maybe it ain't the gun. Maybe it is Officer Bubba and his "man-stopping" hand loads.

The Portland PD thing has been resolved for awhile. The folks I've talked to from the department have said that they think it wasn't a Glock problem. The only folks I've talked to who aren't thoroughly satisfied with their 17s and 19s are a rare few caliber warriors who want 22s or 21s, and one die hard Sig guy. I've sold personal Glocks to more than a few of them. All of this is to say that they're as filled with self loathing as we are, because they also love their Speer Gold Dot 9mm 124gr +P. Yep. Unsupported +P!!! Now THAT is livin' on the edge!!!

We're all gonna die.

bt380 · November 1, 2013, 01:44 PM

Came across this today. For some nice pictures of unsupported chambers:
http://leeprecision.net/support/inde.../glock-warning
Look at the bottom of the article for the pix.

Noreaster · November 1, 2013, 03:49 PM

I have several Glocks, mostly 40S&W. The only KB I ever had was 357sig duty ammo. Big mess and the firing pin channel was packed full of crud afterward but the Glock was fixed and put back into service. The back of the round blew up and the bullet lodged in the barrel. The barrel was salvaged and still runs in it. There was KB at a SWAT course with a guy from another PD using a G21 with reloads so the blame was placed on the ammo.

WESHOOT2 · November 1, 2013, 03:57 PM

Are we confusing "unsupported chamber" with "oversize chamber"?

I think so, but THAT is not limited to Glocks......

Hammerhead · November 2, 2013, 12:21 PM

My old 2nd gen G-21 had a very generous chamber and bulged brass, factory or handloads. It wasn't very accurate either. My buddy's late 3rd gen 21 was much better.
Truth be told, I've become kind of a HK fanboy, but there's nothing wrong with current G-21 chambers. It's a fine gun.

boondocker385 · November 3, 2013, 12:18 AM

I have had a gen 1 model 21 and a gen 3 no kabooms even with hot hand loads. My department has 21s and 22s. I have yet to find even a bulged case....

October 23, 2013, 09:07 PM	#1
Noreaster Senior Member Join Date: January 30, 2011 Location: New England Posts: 1,449	Glock 21 unsupported chamber Just took a Glock Instructor course and a couple of the guys were shooting G21s. With all I've heard about them I was actually looking over my shoulder half the time while firing next to them on the range, would the G21 go kaboom! After the second day I was picking up their brass and looking for the bulge but I couldn't find any. The course was grueling and I was sick of shooting by the end of it. I know I fired over a 1,000 rds so I'm sure the G21 guys did as well. So, based on my experience, do the Gen 4 G21s have better case support or is the whole KB thing really ammo related and not the gun?

October 23, 2013, 10:53 PM	#4
RBid Senior Member Join Date: March 10, 2012 Posts: 1,059	Glock 21 unsupported chamber I think the important thing to understand about .40 and .45 Glocks is that the gubmint buys them for Federal agencies and LE departments because politicians are cop killers who want to wipe out the law through kabooms. These firearms are ticking time bombs, which is why every gun forum is littered with "my cousin was a Navy SEAL , until Glock killed him!" threads. Me? I'm suicidal, so I put as many rounds as possible through my Glock 23 Gen 4. Sooner or later, it'll explode, and I'll get to go see Grandpa Ed and play poker with Elvis and Biggie. If you value life, don't buy these pistols. They'll kill your face right off.

October 23, 2013, 11:11 PM	#5
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 1,057	I own both a Gen3 and 4 G21. I have never been able to run them at high enough pressure to even start to see bulging cases, and I have tried. The recoil gets to be noticeably slide slamming way before the pressure gets high enough to bulge a 45 auto case. I generally use HS-6 and Power Pistol for 45 auto loads. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason

October 24, 2013, 08:14 AM	#8
thedudeabides Senior Member Join Date: August 22, 2012 Posts: 1,031	45 ACP doesn't need a lot of chamber support due to its very low pressures, just look at the chambers in many 1911s. Even when using +P ammo. Now if you want to try 45 Super and test your theory, you're on your own. I think that Glock manufactured a batch of 21s a few years back that had atrocious chamber support (even for 45 ACP), fixed and buried the issue, and went on with their lives. Furthermore, I think it's based on the overall "loose fit" of Glocks that sacrifice fit and accuracy for ultimate reliability to feed and fire all ammo types. __________________ OK, so not all plastic guns are bad

October 24, 2013, 01:12 PM	#10
SPEMack618 Senior Member Join Date: June 21, 2010 Location: Central Georgia Posts: 1,863	I swear ever since I got back from the A-Stan, my sister says I'm different. I didn't realize I was acting suicidal until the internet told me so in regards to my Glock 21. I've shot all kinds of loads, from Wolf range fodder all the way up to Remington and Hornady +P personal defense loads. And with my Gen 3 at that. Now, I'm not exactly a raving Glock fanboy, but when a company that generates most of it's revenue from selling to police forces (as Glock Inc. does) publicy states that a major metropolitan force (Portland PD) is a difficult customer in regards to their "Glock Kabooms" I sorta tend to think that maybe it ain't the gun. Maybe it is Officer Bubba and his "man-stopping" hand loads. __________________ NRA Life Member Read my blog! "The answer to any caliber debate is going to be .38 Super, 10mm, .357 Sig or .41 Magnum!"

October 23, 2013, 09:12 PM	#2
Tactical Jackalope Senior Member Join Date: December 5, 2010 Location: Miami, Florida Posts: 6,429	I personally think it's ammo related when it comes to the .45ACP in Glock. Now with the .40S&W it's definitely an unsupported chamber issue. Primarily in the older models.

October 23, 2013, 09:25 PM	#3
jimbob86 Junior member Join Date: October 4, 2007 Location: All the way to NEBRASKA Posts: 8,722	The .45ACP does not operate at high enough pressure (or is not supposed to- folks running it @ Ludicrous Speed may experience "issues" ..... ) to bulge cases in "unsupported" chambers .... All the KB's I've been aware of locally were in Glocks chambered in .40 S&W, and involved handloads. One was with a mix of lead and jacketed bullets in a stock (polygonal rifled) barrel and the other was in an aftermarket barrel with conventional rifling using bulk jacketed bullets ..... both guys were using very fast pistol powder (one was Titegroup, don't remember the other) in an effort to cut costs (fast powder gives more charges per pound purchased) ......

October 24, 2013, 08:09 AM	#7
bt380 Senior Member Join Date: December 14, 2012 Posts: 331	I'm no gunsmith, but stating the Glock 21 has the problem because of its unsupported chamber, may not be inclusive enough. I have a one year old Beretta Storm PX4 in full sized 40 cal and its chamber is also unsupported. To determine if your 40 cal has an unsupported chamber, when cleaning, and the barrel is out, do the plunk test (dropping a cartridge in it), and check to see if the shell is slightly exposed or not. If exposed, your 40 cal chamber is unsupported. Does that mean your gun should not use the max loads? I have no idea, I'm not a gunsmith and have not read about other pistols having this issue. Perhaps others could speak to this to clarify if this is any 40 cal pistol or what ever?

November 1, 2013, 01:44 PM	#12
bt380 Senior Member Join Date: December 14, 2012 Posts: 331	Came across this today. For some nice pictures of unsupported chambers: http://leeprecision.net/support/inde.../glock-warning Look at the bottom of the article for the pix.

November 1, 2013, 03:49 PM	#13
Noreaster Senior Member Join Date: January 30, 2011 Location: New England Posts: 1,449	I have several Glocks, mostly 40S&W. The only KB I ever had was 357sig duty ammo. Big mess and the firing pin channel was packed full of crud afterward but the Glock was fixed and put back into service. The back of the round blew up and the bullet lodged in the barrel. The barrel was salvaged and still runs in it. There was KB at a SWAT course with a guy from another PD using a G21 with reloads so the blame was placed on the ammo.

November 1, 2013, 03:57 PM	#14
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	not-a-Glock thingie Are we confusing "unsupported chamber" with "oversize chamber"? I think so, but THAT is not limited to Glocks...... __________________ . "all my ammo is mostly retired factory ammo"

November 2, 2013, 12:21 PM	#15
Hammerhead Senior Member Join Date: May 31, 2004 Location: Minnesota Posts: 2,432	My old 2nd gen G-21 had a very generous chamber and bulged brass, factory or handloads. It wasn't very accurate either. My buddy's late 3rd gen 21 was much better. Truth be told, I've become kind of a HK fanboy, but there's nothing wrong with current G-21 chambers. It's a fine gun. Last edited by Hammerhead; November 2, 2013 at 12:40 PM.

November 3, 2013, 12:18 AM	#16
boondocker385 Senior Member Join Date: March 6, 2013 Posts: 640	I have had a gen 1 model 21 and a gen 3 no kabooms even with hot hand loads. My department has 21s and 22s. I have yet to find even a bulged case....