Glock 35, peening to failure

[Sgt127]

AS all Glock 35's seem prone to do, our department issue 35's have exhibited considerable signs of peening along the inside of the slide rails where they contact the frame block. This has not been a major problem in the past and we were assured that this was self limiting wear. Recently, during qualifications, one Glock 35 stopped running. It felt like the slide and frame were welded together and the Officer firing it could not clear it by hand. I realize the "Peening" issue has been talked to death, but its always followed by "Don't worry about it, its normal." I have not heard of a Glock stopping because of this. Having looked more closely at mine, I now see that the peening is getting more pronounced on mine and is pushing the metal out to the sides to the point that it is making faint marks on the sides of the barrel/chamber. The Officer whose gun jammed, is not a shooter and I would guess that his Pistol has had less than 1500 rounds through it. Mine has closer to 2500.

Has anybody else seen a a complete stoppage on a large frame Glock, Particularly the G-35 from the slide rail "peening"?

 

[Radagast]

I've seen a Glock 34 that was getting protrusions on the top of the slide. It ended up going back to Glock in Austria, came back with a new frame with an extra pin in it, IIRC. This took around 8 months to occur.
My personal 17 has around 8000 rounds through it now, the peaning has become more pronounced but hasn't gone as far as you describe.

Radagast

 

[Shake]

Ouch!!! Disconcerting to say the least.

Shake

 

[jamestech]

My third generation G23 seemed to stop peening after 800 rounds or so. It now has 6,000 rounds thru it.

This is using 155 or 165gr ammo.

 

[jamestech]

I now see that the peening is getting more pronounced on mine and is pushing the metal out to the sides to the point that it is making faint marks on the sides of the barrel/chamber.

Peening and any markings on the barrel would not be related.
You will get a little wear where the barrel meets the locking block..which is also one of the Glocks main oiling spots.


What you are describing above is impossible, I would also say that it is impossible for a gun to stop functioning because of peening.

 

[Ironhand]

Thanks for bringing this to my attention. I inspected my 35 #DDEXXXUS, and found some peening on the slide rails right next to the chamber. The left side peen has actually started to scratch the barrel finish. While I have not had any stoppages related to this, is the scratching an indication of things to come? Glock has enough work backed up right now with that 'other' issue, and I frankly don't want to send it back at this time. Any information would be appreciated.

 

[9x45]

Slide peening on all Glocks is normal. My G21 with around 75,000 rounds looks about like my new G26 with about 500 rounds. This would not cause the slide to lockup to the frame.

 

[Handy]

I took my well used 19 apart trying to figure out what you guys are talking about. I couldn't see any peening, but I really don't understand what to look for:

The slide rails contact the frame at the two frame rail inserts. The locking block set into the frame doesn't come in contact with slide or frame rails, just the barrel.

What part is being damaged?
What other part is doing the damage, and when in the cycle does this happen?

Thanks for the clarification.

 

[Sgt127]

"What you are describing above is impossible, I would also say that it is impossible for a gun to stop functioning because of peening."

It may be impossible, but, the gun stopped working while the Officer was firing it, the peening was very pronounced, there are wear marks on the bottom of the barrel/chamber area that line up with the peened areas of the slide and the Officer could not clear it by hand (he described it as the slide felt as if it was welded shut) and, when the peened metal was filed away from the inside of the slide, the gun functioned normally again.

It appears that the metal was being peened out to the inside of the slide until it interfered with the barrel dropping down and out of battery.

For anyone not familiar with this problem with the Glocks, it seems to be most prevalent in the long slide guns, the G34 and G35. Apparently the longer slide causes the frame to flex up more allowing the front edge of the locking block to come up and out of flush with the frame. As the slide cycles back, the inside of the frame rails hits the block. The wear you will see will be inside the slide along the top edge of the slide rail almost exactly even with the rear cut of the slide stop on both sides.

I'm not a big fan of the "its normal" argument. Just because a few Ford Crown Vics explode when rear ended does not, in my opinion, make it "normal" behavior for American made Sedans. These are two parts of a machine that are striking each other causing damage to each other during normal use. We have over 200 Glocks issued. All of the big frame guns have the peening, This is the first one we have seen that, we believe, stopped the gun. Issue ammo is the Corbon 135gr. Practice ammo is generally Winchester Generic.

The purpose of my original post was to see if anybody else had a Glock that had stopped because of this, if others care to see if there Glock is doing the same thing, I hope they do. The bottom line is, we are quite sure why this gun quit working, we just want to see if it has happened to anybody else. You can do a search at Glocktalk on "Glock35 peening" and see pictures and discussions on this subject.

 

[M58]

Sgt, I am not doubting your report.
Is there any chance the casing bulged in the chamber and caused the binding?
How was the gun opened?
Was the casing examined?
Was the filing done before re-assembly to check function by hand?
My G24C and G31 have a lot of gouging; they date from 1997-98.
Retired.

 

[Sgt127]

No. the case was fine. It was during night fire, and we always shoot up the issue Corbon during night fire. And, I know it did not split or bulge. It was taken apart by the range officer by gently rapping it against a wooden post (sigh) which promptly would have sheared off any little burrs that may have been kicked up. Manually cycled, you could feel a "catch" After the filing, it was smooth again.

 

[IDPAguy]

My 34 was getting pretty bad so I filed off the metal that was sticking out with a point file. The gun was still functioning fine but I didn't want to wait till it did quit.

 

[Ironhand]

My 35 froze recently after firing. I just figured the case stuck, that it was an isolated incident. I had to clear it with the 'slide push' on a wood surface to get it out of battery. I have filed it since reading this thread, so I guess I won't know for sure what caused it. I did have quite a bit of peening, though.

 

[Hard Ball]

Check the serial number range of your department's pistols with Glock Sgt127. You may have some Glocks whose rails are made of "inferior metal" to quote Glock and may need to have Glock replace your frames with new correctly manufactured frames.

 

[AZ Jeff]

Peening of the slide near the rails is common in Glocks, ESPECIALLY in the larger calibers (above 9mm). I have a G19 with jillions of rounds thru it, with no peening. On the other hand, my G24 was peening in it's first 200 rounds.

Peening is caused by the barrel locking block front edge "flipping up" and smacking the bottom of the slide when the barrel stops at it's full rearward position in recoil.

Glock saw this happen when they modified the model 17 frame to take the .40S&W cartridge when creating the G22. Their "fix" for the problem was a second pin in the frame to restrain the locking block more securely. The fix is not total--it still peens, but less than it would without that pin.

On slides that show extensive peening, the Glock recommended fix is to stone the extruded material away where it protrudes into the area occupied by the barrel. A PD armorer should be aware of this recommended procedure, and should be checking dept. issued Glocks for this symptom on a regular basis.

For us civilians, we just gotta watch out on our own, and do the same fix as necessary.

 

[AZ Jeff]

One more comment on the peening--this has NOTHING to do with the recent "voluntary upgrades" on the "Exx" series frames. Also, it has NOTHING to do with the previous firing pin& safety "upgrade" of 10 years ago. Peening has been around since the G22 hit the market.

 

[Handy]

I take this as more evidence that creating a .40 handgun by adapting a 9mm handgun isn't necessarily the best idea.

 

[M58]

OK
thanks SGT.

 

[Mike Davies]

Nobody mentioned the "subsequent damage" that can occur if the peening is allowed to go unattended. If the peening spreads out inwards, the newly-created edges will slice both sides of the tops of your mags....not good. I stoned the sharp edges off of my G35's slide's peened edges when it became quite visible (at around 1500 to 2000 rounds), and began to cut my mags. I now have between 8000 and 10000 rounds through my G35, and the peening has not gotten worse since I cleaned it up.
FWIW

 

[Ironhand]

Interesting. Your G35 was nicking your magazines while mine was nicking my chamber block. I checked my mags after reading your post, and they were fine. YMMV I guess.