• If you enjoy the forum please consider supporting it by signing up for a NES Membership  The benefits pay for the membership many times over.

CAUTION from Glock on Dry Firing!

Len-2A Training

Instructor
Instructor
NES Life Member
NES Member
Rating - 98.6%
71   1   0
Joined
Feb 26, 2005
Messages
53,440
Likes
12,515
Location
90% in NH
I do NOT want to get into a "religious battle" here, but I was asked to pass this info along by a senior technician at Glock-USA's customer service department, so here goes! [If you doubt it, please contact Glock and ask them yourself, don't blame me . . . I'm just the messenger. [wink] ]

- Glock-USA told me that we SHOULD use snap-caps for extensive dry fire sessions.

- That the pictures of "punched out" slides I've seen and the damaged product that Glock has replaced are due to repeated dry-fire sessions without anything to support the area that a case would normally occupy in the chamber.

- Glock has NO caution in the manual (the technician told me that this was an oversight/mistake on their part), therefore if you don't do this and punch out a slide, they WILL replace it under warranty. But this is a risk that you run in not using snap-caps.

End of Glock customer service message.

-----------------

Personal opinion follows:

- I've seen the pictures on GlockTalk of punched out slides. The damaged area is approximately the same size as a cartridge rim.

- I have a degree in EE, but we had enough Mechanical Engineering courses to understand something about materials.

- My engineering background tells me that the damage that I've seen pictures of and the admonition by Glock's technician correlate as most probable "cause and effect".

- In summation, I think that Glock is correct in asking us to use snap-caps.

Again, if you doubt what I stated above, please call Glock and ask them instead of arguing about it here.

Thank you.
 
Rating - 96.3%
77   3   0
Joined
Jan 31, 2007
Messages
3,637
Likes
430
No comment or arguement, just a couple questions from a lay person:

What is a ""punched out slide?" and how MIGHT that be caused by dry firing?

How might I find out if any other guns (M&P or XD, for instance) are susceptible?

And thanks for the info, Len.
 

Len-2A Training

Instructor
Instructor
NES Life Member
NES Member
Rating - 98.6%
71   1   0
Joined
Feb 26, 2005
Messages
53,440
Likes
12,515
Location
90% in NH
GlockTalk has had a number of pictures of the problem but I've never saved a picture and have no idea where it would be. Basically the steel back of the slide behind a normal case breaks out in the shape of a cartridge rim.

Yes, the logic of this is not unique to Glocks. I'd be wary of creating a similar problem on any other semi-auto as well.

Therefore, snap-caps all around is a good and safe bet.
 

FPrice

Retired Zoomie
NES Life Member
NES Member
Rating - 100%
77   0   0
Joined
Apr 29, 2005
Messages
20,875
Likes
6,902
Location
Western Mass
What is a ""punched out slide?" and how MIGHT that be caused by dry firing?

I think that I have heard something similar before. If I recall correctly, what happens is that the "body" of the firing pin impacts the back section of the slide area where the actual firing pin protrudes through to strike the primer. (It might actually be impact passed through the compressed firing pin spring.) Over time this can weaken the area much as a metal punch may do. Without the pressure and reinforcement of the shell casing on the opposite side, the metal can eventually weaken and be punched out. At least that's what I recall.

Using a snap cap should help by providing force to counteract the impact from behind.
 

Len-2A Training

Instructor
Instructor
NES Life Member
NES Member
Rating - 98.6%
71   1   0
Joined
Feb 26, 2005
Messages
53,440
Likes
12,515
Location
90% in NH
A picture is worth a thousand words!

Cracked_breech2.jpg


BTW: MY Google search found a site that implied that this happened on another brand of pistol as well.
 

drgrant

Moderator
NES Member
Rating - 100%
61   0   0
Joined
Mar 21, 2006
Messages
76,071
Likes
48,760
This is certainly bizarre. I've heard of excessive dry firing in
some pistols causing busted up pins and pin stops, but never anything
like that!

-Mike
 

icyclefar

NES Member
Rating - 100%
46   0   0
Joined
Jun 12, 2006
Messages
5,331
Likes
1,014
Location
South Shore
A picture is worth a thousand words!

Cracked_breech2.jpg


BTW: MY Google search found a site that implied that this happened on another brand of pistol as well.

O.K. ........... I am not an Engineer, but I do play one at work.

I have seen my fair share of mechanical failures and each one of them tends to leave "finger prints" that give you a clue as to what went wrong.

Take a good look at the picture, notice the nice tell tale rings, the larger punched out ring is the same size as the O.D. of the cartridge case, the smaller ring is the same O.D. as the primer pocket of that case.

Now do you suppose that the actions of the slide chambering a round and slamming into the back of the cartridge, coupled with the back force produced when the round is fired could be responsible for the "stress" ............ I'd bet money on it!

Besides, have you ever stripped a Glock down to the firing pin .......... there is nothing on it that gets close to that diameter.

Just my two cents ..............
 

FPrice

Retired Zoomie
NES Life Member
NES Member
Rating - 100%
77   0   0
Joined
Apr 29, 2005
Messages
20,875
Likes
6,902
Location
Western Mass
Now do you suppose that the actions of the slide chambering a round and slamming into the back of the cartridge, coupled with the back force produced when the round is fired could be responsible for the "stress" ............ I'd bet money on it!

That sounds pretty much like the same actions and forces present in any semi-automatic pistol.
 

EddieCoyle

Consigliere
Moderator
NES Member
Rating - 100%
144   0   0
Joined
Nov 11, 2005
Messages
21,104
Likes
7,854
Location
Northern, MA
O.K. ........... I am not an Engineer, but I do play one at work.

I have seen my fair share of mechanical failures and each one of them tends to leave "finger prints" that give you a clue as to what went wrong.

Take a good look at the picture, notice the nice tell tale rings, the larger punched out ring is the same size as the O.D. of the cartridge case, the smaller ring is the same O.D. as the primer pocket of that case.

Now do you suppose that the actions of the slide chambering a round and slamming into the back of the cartridge, coupled with the back force produced when the round is fired could be responsible for the "stress" ............ I'd bet money on it!

Besides, have you ever stripped a Glock down to the firing pin .......... there is nothing on it that gets close to that diameter.

Just my two cents ..............

I agree. My guess would be that the crack forms with use and is exacerbated by the work-hardening of the slide. The chunk then breaks out during dry firing. I don't care though. I love Glocks.
 
Last edited:

RKG

NES Member
Rating - 0%
0   0   0
Joined
Dec 7, 2005
Messages
3,812
Likes
638
Location
Boston
GlockTalk has had a number of pictures of the problem but I've never saved a picture and have no idea where it would be. Basically the steel back of the slide behind a normal case breaks out in the shape of a cartridge rim.

Yes, the logic of this is not unique to Glocks. I'd be wary of creating a similar problem on any other semi-auto as well.

Therefore, snap-caps all around is a good and safe bet.

Actually, the issue with respect to Glocks (to wit: the striker slamming into the forward-most part of the striker tunnel in the frame) would not apply to pistols based on the 1911 design (i.e., inertial firing pin struck on the rear by a hammer). The reason is that major force (the hammer) is trapped by the firing pin stop plate, which is designed for this impact (since even on normal firing, the hammer fall is stopped by the stop plate while the pin continues to travel forward) and since the force of the pin once its rear face has moved forward of the hammer's forward face and is now being retarded by the firing pin spring is far less than that of the Glock striker still propelled by the main spring.

Said a different way: the Glock issue is based on the absence of a cartridge and primer to cushion the forward blow of the striker. But with a 1911-style pistol, the cartridge and primer does not cushion the forward travel of the hammer, in any event.

Also, if you look at the shape of 1911-style firing pins, it is clear that the shoulder that ultimately stops their forward travel is far further aft on the pin that it is apparently on the Glock strikers, which would seem to make the notion of punch through all but impossible.

Kuhnhausen does not caution against dry firing 1911 pistols.

I would guess that a similar analysis also applies to pistols based on the 1911 inertial firing pin design, even where they do not have a separate firing pin stop plate (e.g., Sigs, Browning HPs), but like the 1911-style pistols, also do not rely on a cartridge and primer to cushion hammer fall.
 
Last edited:

RKG

NES Member
Rating - 0%
0   0   0
Joined
Dec 7, 2005
Messages
3,812
Likes
638
Location
Boston
I wonder what defines extensive dry firing. After a chamber check I always dry fire my Glocks when putting them back in the safe.

With the exception of some .22 rimfires, I wouldn't worry about a single occasional dry fire, and it is a good idea to store firearms with the main springs uncompressed.

With rimfires, there is some risk of the pin hitting and peening the chamber, particularly on .22 revolvers with rebated chambers, and so I'd lower the hammer by hand. Likewise with bolt actions: you can usually lower the striker by pulling the trigger as the bolt handle is lowered, without the need of dry firing.
 
Rating - 0%
0   0   0
Joined
Aug 31, 2009
Messages
1
Likes
0
the picture does show!

A picture is worth a thousand words!

Cracked_breech2.jpg


BTW: MY Google search found a site that implied that this happened on another brand of pistol as well.

Hi Len,

I am a little confused about the picture and the subject matter? The picture with the crack seems to me to be the near mirror image of the outer circumferance of the casing? Hmmm

The smaller circular image appears to be the approximate diameter of the primer. which is approx 1/32nd to 1/16th larger than the partial circular structure around the tip of the firing pin.

If the impact of the firing pin body striking on the inside toward the out was to be responsible for a bludge or in this suggested case, the "crack" it seems to me that the crack should be in at least the near vicinity of the repeated impacts, not 2.5 to 3.5 times away from the diameter of the object striking?
Have you ever broke a hole in a cinder block with a hammer? Striking in the same place produces a hole nearly the same diameter as the hammer head. Certain types of wood as well. I have seen simular with metal repeatedly stress in one area. If in fact the crack was the result of dry firing I would bet that it was indirectly caused by the dry firing stressing a very weak or defective area in the metal casting or forging which would be the true cause of the crack. Still curious that it appears at the area the rim would reside?
Any thoughts? Am I missing something here?
 
Rating - 100%
62   0   0
Joined
Apr 16, 2009
Messages
5,530
Likes
1,351
Location
Free Hampshire
- Glock-USA told me that we SHOULD use snap-caps for extensive dry fire sessions.
.

The key words are "EXTENSIVE DRY FIRE", this shows that the operators are abusing the Glock to see if it will fail. The only time you need to dry fire a Glock is when you are feild or detail stripping the firearm! Don't abuse your firearms and you will save money which you can then spend more time shooting [grin]
 
Rating - 100%
62   0   0
Joined
Apr 16, 2009
Messages
5,530
Likes
1,351
Location
Free Hampshire
Also, please remember that the slide, barrel and the Glock night sights have been treated with the Tenifer procees which hardens these parts to a 64 Rockwell C hardness rating and as a result Glock has given them a Lifetime Warrenty.
 
Rating - 100%
2   0   0
Joined
Mar 26, 2007
Messages
1,828
Likes
246
Location
Plaistow, NH
Look to me like dry firing causes the piece to break out, but the thing causing the ABILITY for the piece to break out is the normal function of the pistol. If other guns don't have this problem, something seems to be wrong with how Glock is doing things.

If the pressure of a firing pin is shearing a large cylinder of metal out of the slide, something is very wrong, IMHO, and a sign that something may be off in the HT of those slides...
 
Rating - 100%
2   0   0
Joined
Mar 26, 2007
Messages
1,828
Likes
246
Location
Plaistow, NH
Also, please remember that the slide, barrel and the Glock night sights have been treated with the Tenifer procees which hardens these parts to a 64 Rockwell C hardness rating and as a result Glock has given them a Lifetime Warrenty.

Tenifer process is only .05mm thick. Whats the RC/composition of the metal below that which is cracking out?
 
Rating - 100%
62   0   0
Joined
Apr 16, 2009
Messages
5,530
Likes
1,351
Location
Free Hampshire
Look to me like dry firing causes the piece to break out, but the thing causing the ABILITY for the piece to break out is the normal function of the pistol. If other guns don't have this problem, something seems to be wrong with how Glock is doing things.

If the pressure of a firing pin is shearing a large cylinder of metal out of the slide, something is very wrong, IMHO, and a sign that something may be off in the HT of those slides...

Tenifer process is only .05mm thick. Whats the RC/composition of the metal below that which is cracking out?

AGAIN, The key word is EXTENSIVE. There is NO need to extensivly dry fire a Glock!!! Other guns don't have this problem becuase they are not made to way a Glock is and can't withstand what a Glock can. Because of this a FEW people have taken it upon themselves to EXTENSIVLY torture a Glock until it fails!!
I challenge anybody to come down with their factory pistol and I will gladly put it up against one of my Glock's and we will see who wins, and I will provide the ammo.
It also doesn't matter how thick the Tenifer process is, rather that it has been done. What does matter is that people have chosen to EXTENSIVLY ABUSE their firearms to make it look like all Glock are the same. It is unfortunate that a small number of people have chosen to perpetuate the lie and the myth that all Glock's will fail becuase of this minor bit of EXTENSIVE ABUSIVE TESTING.
Remember, if your Glock has any problems to either the slide, barrel or the Glock night sights they have a LIFETIME WARRENTY. Of course if you have EXTENSIVLY ABUSED your Glock then you have voided the warrenty as you would have done with any other firearm manufacturer.
 

drgrant

Moderator
NES Member
Rating - 100%
61   0   0
Joined
Mar 21, 2006
Messages
76,071
Likes
48,760
FWIW I view this as some kind of manufacturing anomaly.

I think Glock had a problem with some of their slides and instead of trying to figure out how to orchestrate a recall, they just said "well, this don't happen if people refrain from dry firing excessively..." This looks like some sort of metallurgical problem.

As much as I like Glock's CS the company is "never wrong" up front and has never issued a recall. [laugh]

The reason I say this is because I have a very close friend who is OBSESSIVE about constantly dry firing. He has yet to do this to any of his Glocks. This is a man who will dry fire a pistol until his hand/arm gets tired or sore.

I think Glock had some kind of snafu here and this is their "workaround".

Besides, if it happens, just send the gun in and they'll fix it.


-Mike
 

drgrant

Moderator
NES Member
Rating - 100%
61   0   0
Joined
Mar 21, 2006
Messages
76,071
Likes
48,760
Of course if you have EXTENSIVLY ABUSED your Glock then you have voided the warrenty as you would have done with any other firearm manufacturer.

Then why is it, that (as discussed earlier in this thread) that Glock will replace slides damaged in such a manner for free?

If they weren't ashamed of this happening at some level, then they wouldn't do this for free.

-Mike
 
Rating - 100%
3   0   0
Joined
Dec 11, 2009
Messages
2,910
Likes
417
Location
NeffingH!!!!!!!!!
I just wish I had perused the "firearms" section of the forums before now!

Just bought a G22 DPD a few weeks ago. Probably DF'd around 200 times... I wouldn't think this is excessive, but I now know how many I am gonna do tonight:

0
 
Rating - 100%
4   0   0
Joined
Nov 7, 2008
Messages
3,818
Likes
684
Location
The Free State of New Hampshire!!
Dillon's "Blue Press" gave an interesting tip a few months ago in regards to dry-firing Glocks (this works for others, such as a Springfield XD as well). You can put a small piece of paper between the slide and the chamber (on an unloaded firearm, of course!) so the slide closes around 95% of the way. This allows the trigger to disengage and reset while not engaging the firing pin. You don't get the satisfying "click", but you can practice the trigger without having to rack the slide and chase around snap caps constantly.
 
Top Bottom