Glock still have unsupported chambers?
- Thread starter Fatelvis
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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
Member
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!!
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!!
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.
LiveLife
Member
IMHO, it is more of an issue with rifling unique to Glock.ny32182 said:
Unlike true polygonal rifled barrel 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.
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
Member
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).
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
Member
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
I am not a big handgun shooter, although I should find the time to practice more.
QM
WinThePennant
Member
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.
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
member
9mm is not a low pressure round. It's very close to .40 and probably higher given the +P renderings.
WinThePennant
Member
You are right, but it's easier to overpressure the .40. Especially with the 180 grain round.
Ar180shooter
Member
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.
)
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.
)
Deaf Smith
Member
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
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
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
member
Weevil
thank you for the picture
That certainly clears things up
thank you for the picture
That certainly clears things up
quartermaster
Member
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.
quartermaster
Member
Thanks HOOfan 1
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