Interesting Glock failure mode

At a USPSA match last week, a competitor was using a well-worn Glock. During the course of fire, his gun quit. He pulled the trigger and got nothing. He racked the slide and got nothing. No piece of brass or live round ejected. Repeated cycling of the slide did nothing. We started to clear the gun and noticed that the barrel wasn't unlocking from the slide.

We eventually had to field strip the gun on the course in order to clear it, and we discovered that the locking lug (if that's the right terminology) at the bottom of the barrel below the chamber had sheared off into the frame! When we pulled the barrel out of the slide, an empty/fired piece of brass dropped out.

The next day, the gun's owner dropped by Glock's USA HQ and they took care of him with a new barrel. So good job there.

Anyway, I thought it was an interesting failure mode, and one I hadn't seen before. Proof that every mechanical device, and just about every aspect of a mechanical device, can fail, given enough chances.

 

All bets are off when using re-loads (and my Spidey-senses are telling me he's been using a lot over the years).

 

I was about 3' away when it happened. It was certainly not a hot round, nor a squib. Shooting non-open in 9mm, the motivation is to shoot really soft loads, not hot ones.

But, sure, there's a possibility he shot a bad one in the past and the effects just didn't show up until way down the road.

 

Everything made by human hands - and humans and most items in nature - have a finite life span. Everything wears out, erodes, degenerates, breaks or turns green on one's finger.

Even Glocks.

From the description (well worn) the recoil spring may not have been springing like it should. This increases wear and stress on the moving parts, like the locking movement device at the bottom of the barrel. Hot loads or ammo is surely a possibility, but long term wear and stress (banging) sound likely to me as well.

 

Had a P-35 do that to me once. Sheared the lug on the bottom of the barrel.

Why? Very hot reloads I used for a while. The slide force is so great that over the time it fractures the lug off from all the impact with the cam.

Bet that's the case here to. Plus add a recoil spring that is old and very very worn. That increases the slide velocity to.

Deaf

 

Had that happen with factory ammo in a Glock 27 years ago.
Glock replaced the barrel promptly.

 

Doesn't take "Spidy Sense" to conclude anyone shooing competitively is shooting reloads. Unless you're rich or sponsored, if you shoot competition regularly, odds are great you reload. For the record, that's not a bad thing.
str1

 

Go to enough matches and you will see every type of gun failing in all sorts of ways.

 

If he was using exceptionally hot reloads to shoot USPSA, he'd be one of the first. Most of the loads being used in USPSA in divisions other than Open are on the light side of the curve compared to most factory ammo.

There is nothing magical about factory ammo. MOST of the cheap stuff is inconsistent.

A lot of competitive shooters use lightened recoil springs. Whether that causes harder hits to the locking lug on the barrel, I don't know... I used 13lb springs on my G34 when I shot those in competition.

I have a buddy that cracked a G21 slide after 20+ years and 180k rounds. If he's shooting enough to break a major component on a Glock, the expense of a new part is nothing. Replace it and rock on.

 

No idea re: round count; I'm sure it was considerable. Agreed with those who dismissed hot loads as the likely explanation. And definitely agreed with tarosean's observation that if you watch enough matches, you'll see everything fail about every way.

 

I broke the link lug off a 1911 .45 barrel with regular use of Major (less than hardball) loads. Machines wear out.

It amuses me when one of the Ballistic Jewelry Collectors is alarmed to find wear marks on his very occasionally shot multi-kilobuck custom gun.

 

I never said that he was using hot reloads at the time, or that reloads were a bad thing. But the cumulative use of hot ammo over time can cause metal fatigue. It's just physics.

Also not saying that Glocks are failure-proof. Just tossing out a possible contributing factor to the failure the OP witnessed.

 

That sums it up. Pretty much anything can break eventually.

A lot of the guns on the field have seen more rounds than the average gun owner will fire in their lifetime. Would you get mad at your car if the water pump broke after 300,000 miles? Of course not - fix it and move on.

 

Just out of curiosity, (and maybe I missed this) which Gen and model was it?

 

G17. Don't know what generation.

 

I was at a long range precision rifle match last week and witnessed a Harris bipod break in half. A critical part simply sheared, and the legs fell apart from the mount. Everything will fail. No reflection on Glocks or the ammo used. Probably just fatigue from hundreds of thousands of cycles.

 

If you run into him again, see if he knows what the round count was. Just curious, as my one 17 just passed 93,500 yesterday, and so far, all that has broke, was the trigger spring back in September at 88,900 rounds.

Trigger was actually still working too, as long as you held it back when the slide was manually cycled, or the slide released, and you held the reset while shooting.

That, and a short stint replacing what was thought to be a bad extractor, and then putting the "bad" one back in, as it turned out to be worn out brass. Other than that, its been pretty boring and uneventful. Still going strong too.

I shoot mostly reloads, and mine are pretty warm. I also usually shoot about a case of +P+ between it and one of my 26's each year. Glocks like them warm, and run better when they are.

 

Over 88k rounds on a trigger spring has got to be some kind of record... Is that with dryfire or just live rounds?

Trigger return springs are one thing I replace on a schedule in every pistol I've ever shot a lot (recoil springs being the only other part in this category) as I've broken them, and had too many friends break them in different guns to want to chance having a match ruined by a high mileage trigger return spring.

 

Follow up: 1st Gen Glock 17. He did not know the round count, but it was surely very high. When he took it to Glock, they didn't just replace the barrel.... basically everything but the frame and the slide came back new. Those guys know how to delight a customer.

 

Both. It gets dryfired a good bit everyday, and shot once or twice a week.

 

Glock "perfection". Sure.

 

I'd wonder about the round count on the recoil spring. I'd also wonder about the condition of the locking block pin, if the RSA was seen a excessive use without being replaced.

I was talking to another armorer (online) a while back, and he mentioned that his agency's G23 inventory, which had never received RSA replacements, had started having some broken front barrel lugs. He said the guns had been in-service for over 10 years. I'd also heard of it being mentioned by an armorer in one of my armorer recerts at one time or another.

Probably why armorers have been told in my last couple of recerts that if we're seeing broken locking blocks, locking block pins, trigger pins, etc ... that we're not replacing the RSA's often enough.

Sure, it's not impossible to suspect that some occasional instance of user/owner abuse or 'modification' might happen, or an unknown/unrecognized defective barrel might slip out of the factory.

FWIW, I've heard in different recert classes that some of the other small parts, like the trigger coil springs and the locking block pins, have received different heat treating over the years as engineers worked to extend their useful service lives.

Such parts and assemblies have been referred to as 'wearable parts' in recent years (in armorer classes), meaning that they will require periodic inspection to check for normal wear occurring, and replacement, as necessary, during the service life of the gun.