Glock, or the ammo? (off center primer strikes)

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sequins

sequins

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A glock 17, 19, and 26 are all exhibiting failure to fire. Upon examination, the failed strikes appear to be off center.

All three glocks are purchased in the last 6 months and are gen 5s.

Does this seem like an ammo issue or a gun issue? How could all three glocks have the same problem? And yet the ammo appears to be in spec... anything I can test to get to the bottom of this?

Asking for a friend, lmk if any other pics would be helpful.
 
My guess is that the ammo that fails to fire is slightly oversize, preventing the gun from going fully into lockup. Due to the design of the gun, that will place the barrel out of line with the breechface and so the primer hits will be off-center and light.

I have had issues with S&B 9mm ammo failing to chamber in some pistols. Not Glocks--I've never shot any S&B in Glock pistols. Maybe 3-5 rounds out of a 50 round box wouldn't fully chamber. The other rounds would chamber and fire with no problems.

Some Gen 5 Glocks are known to have slightly different chamber throat specifications than the standard Glocks and some ammo that will chamber and fire in the older generation Glocks may hang up in the Gen 5 guns. I have personally witnessed a situation where a Gen 5 Glock would jam on dummy ammo that fed fine through older gens.

So a combination of two issues, one with the ammo, the other with the guns.

I suspect that if the owner tries some different ammo, the problem will disappear.
 
Thanks guys I'm going to measure those pieces, some successfully fired cases, and some fresh untouched loaded rounds to see if I can learn anything more.

Didn't realize a glock would show off center strikes on oob. In fact, I didn't realize it would fire oob at all...
 
Ammo, almost certainly. My Gen 5s do much the same with longer ammo loaded with wide meplat bullets, like flat nose 147 grain FMJ or some JHP I have loaded to 1.12".

It's from the tighter chamber of the Gen 5 Marksman barrels. A dubious upgrade that hasn't netted me any increased accuracy but has had a negative effect on reliability.
 
This is S&B 115gn round nose plinker ammo, I'm surprised the gen 5 barrels are choking on such standard ammo.

This seems like a gen 5 issue tbh if the threats are so tight it chokes on off the shelf 115gn ammo.
 
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sequins said:
This is S&B 115gn round nose blinker ammo, I'm surprised the gen 5 barrels are choking on such standard ammo.

This seems like a gen 5 issue tbh if the threats are so tight it chokes on off the shelf 115gn ammo.
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Well that is a bit unusual then, mine have never had an issue with factory round nose ammo, or any round nose I've loaded (numerous thousands), just wide flat bullets

Edit: or factory JHP mine all have run GS, Gold Dot and HST perfectly
 
I'm going to have him shoot 100rd of blazer and I'll shoot 100 of my reloads to test, in addition to taking measurements. Could just be a bad batch of S&B.
 
This seems like a gen 5 issue tbh if the threats are so tight it chokes on off the shelf 115gn ammo.
Click to expand...
Like I said, I've run into this with other pistols (2 Ruger P-Series) when using S&B and I've seen at least one other person state that they have had the same problem with P-Series Rugers and 9mm S&B. This was over a period of years, so I don't think we can write this off as just a single bad batch of S&B either.

So the fault isn't exclusively the Gen5 changes. Since it wasn't happening with every round we already had a clue pointing in that direction.

But it is certainly true that there are some chambers that have issues with the S&B variance in dimension and some that don't.

That's why I think it's most accurate to say it's a combination of two issues.
 
JohnKSa said:
My guess is that the ammo that fails to fire is slightly oversize, preventing the gun from going fully into lockup. Due to the design of the gun, that will place the barrel out of line with the breechface and so the primer hits will be off-center and light...
Click to expand...

This. Rare, but not unheard of. Either with reloads, or with S&B most often so it tracks there also.

Failure to fire is on purpose. A safety feature for then the gun is not in battery. The light strike is a quirk off the design, that the striker can still go forward a bit, but it deliberately won't fire the cartridge.
 
If it was a Glock-issue and not an ammo issue, I'd suspect the owner took apart the Glocks and reinstalled the slide LOCKs backwards, in all three firearms.
 
Something is odd there, those strikes dont look like a Glock striker made them. They look more like a standard round tipped firing pin made them, and not the "chisel" strike you usually see with the Glocks. Even more odd that it happened across three different guns.
 
I've got a G19 gen 2 that I experience light off center strike's with the slide not quite in battery. I've replaced the RSA twice and still have the problem. It sits in the safe now.Any thought's? Could a magazine be a cause, I'm leaning not, but....
 
Thanks for all the advice you guys. We're going to see what the exact measurements are for several pieces of 9mm this weekend and confirm function with various rounds. I'm optimistic it's ammo related since people seem to have s&b specific issues.

I'm learning a lot about glocks and the gen 5 differences thanks to this thread, didnt know the firing pin changed!
 
L-2 said:
For Post 12, the latest Gen5 Glocks have a circular, not rectangular/chisel-shaped firing pin tip.
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Yup, youre right! What do ya know :)

I shot my 45 this morning and was just looking at the brass, and sure enough, its a round strike. First I noticed it, and probably wouldnt have if I didnt see this thread. Thanks for pointing it out. :thumbup:

All the srtikes on the brass I just checked, were all pretty much dead center too, by the way. All my reloads and all mixed brass.
 
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Something is odd there, those strikes dont look like a Glock striker made them. They look more like a standard round tipped firing pin made them, and not the "chisel" strike you usually see with the Glocks. Even more odd that it happened across three different guns.
Click to expand...
Even with the chisel type firing pins, a light strike from a Glock will often look more like a conventional round-tipped firing pin strike.
I've got a G19 gen 2 that I experience light off center strike's with the slide not quite in battery. I've replaced the RSA twice and still have the problem. It sits in the safe now.Any thought's? Could a magazine be a cause, I'm leaning not, but....
Click to expand...
Something is preventing the gun from going completely into battery. Assuming that the ammunition is in spec--that would be the first thing to check--there's some other issue. Could be a burr or deformation on the slide or barrel lockup surfaces. It is unlikely to be a magazine issue. If you can find an outdoor GSSF match taking place in your area (Hallsville?), you can take the gun (unloaded) to the match and have the match armorer look at it. They will examine it at no charge and possibly repair it depending on the issue.
 
I have 2 Gen 5 guns. A 19X and a 45.
They have never had an issue with any factory ammo I have fired in them. I have never tried Sellier & Bellot ammo in them but I have tried many others, FMJ and SD, but never that cheap Russian stuff.

My money is on the ammo
 
JohnKSa said:
Even with the chisel type firing pins, a light strike from a Glock will often look more like a conventional round-tipped firing pin strike.Something is preventing the gun from going completely into battery. Assuming that the ammunition is in spec--that would be the first thing to check--there's some other issue. Could be a burr or deformation on the slide or barrel lockup surfaces. It is unlikely to be a magazine issue. If you can find an outdoor GSSF match taking place in your area (Hallsville?), you can take the gun (unloaded) to the match and have the match armorer look at it. They will examine it at no charge and possibly repair it depending on the issue.
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Just to add a note here, it doesn't happen every rd. But often enough that I can't trust it. It's just slightly out of battery. But I willmake a call to Glock.
 
Without pictures of the rounds that did fire, we have nothing to compare it to??
Did you try a second strike on the "failed" rounds?? Did they go bang then?
What exactly are you going to "measure" that will reveal anything?
 
Rule3 said:
What exactly are you going to "measure" that will reveal anything?
Click to expand...

If the issue is caused by out of spec ammo length, measure COAL and case length. See if there is a relation between length and rounds that fire/misfire or off center primer strike. I have done the same checks on some of my more picky firearms of the past. Looking at you AMT.
 
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