New Blog Article! Lessons learned at the range about my EDC and mechanical parts failure.

Racer88

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Interesting. Good thing you were at the range and not pulling the trigger in self-defense!

7,400 rounds feels low for a break. Not an expert. I did just read up on some instances people have run into and some do hit an issue at 5K though the norm seems well north of 5K and 7K. Makes you pause for a moment. You need to fire the weapon enough to have confidence that it works and enough to stay in practice. Wonder if this could be an argument for breaking in an EDC but then using a like config for practice with minimal use of the EDC just to keep the parts in "tip top" shape?
 
Makes you pause for a moment. You need to fire the weapon enough to have confidence that it works and enough to stay in practice. Wonder if this could be an argument for breaking in an EDC but then using a like config for practice with minimal use of the EDC just to keep the parts in "tip top" shape?
Right. So, firing it a lot (without problems) is a good way to ensure reliability. But then again... firing it a lot could precipitate parts failures. So, where is the happy Goldilocks zone?

To me... for now... I'm thinking I should keep practicing with my EDC but come up with a schedule to replace critical parts.
 
Right. So, firing it a lot (without problems) is a good way to ensure reliability. But then again... firing it a lot could precipitate parts failures. So, where is the happy Goldilocks zone?

To me... for now... I'm thinking I should keep practicing with my EDC but come up with a schedule to replace critical parts.
Doesn't that create a catch-22 though? Replace the "critical parts" and then you need to put 1,000 rounds (your preferred testing count which I am not condemning you for doing) before carrying it again? Or are you thinking you'd just carry something else for a month or so while you confirm it is ok?
 
Doesn't that create a catch-22 though? Replace the "critical parts" and then you need to put 1,000 rounds (your preferred testing count which I am not condemning you for doing) before carrying it again? Or are you thinking you'd just carry something else for a month or so while you confirm it is ok?
In this case, I'd simply replace the firing pin and test it at the range once. I know the gun is reliable overall. No stoppages ever. This is a single part that broke. I'll replace it with another OEM Glock firing pin, of course. Take it to the range to confirm no problem... and good to go, I think.
 
First off, great read. Aftermarket slide, right? Would it be possible that the pin is bottoming out on the inside of the slide when fired causing pre-mature wear? I would guess an OEM pin would last longer than your round count.
 
Aftermarket slide, right? Would it be possible that the pin is bottoming out on the inside of the slide when fired causing pre-mature wear?
Yes. Slide is aftermarket.

Of additional note is that I've done a bit of dry fire with this gun, but almost always with snap caps.

That said... "bottoming out" would not affect the part of the pin that protrudes through the hole in the breach... unless the hole was off-center and the "striker" part of the firing pin was impacting the sides of the hole, eh? At least that's how I visualize it.

I did not observe any peening on the striker part of the firing pin. (I still have it.)

I am more prone to believe it may be related to the hardness of the primers in the ammo I use. The vast majority of that has been CCI Blazer Brass 124-gr, for whatever that's worth.

I paused while writing this comment to do a search about CCI primers possibly being hard. And.... well... here ya go!

1706489023572.png
 
In this case, I'd simply replace the firing pin and test it at the range once. I know the gun is reliable overall. No stoppages ever. This is a single part that broke. I'll replace it with another OEM Glock firing pin, of course. Take it to the range to confirm no problem... and good to go, I think.
I'd call the firing pin/striker a fairly safe swap. By critical parts, I assumed you'd be swapping all springs - the trigger/connector spring being the one I'd probably be most concerned with causing a problem as a little twerk in it can cause reset/dead trigger issues in my experience. Not to mention swapping it more or less requires pulling most of the LPK guts out.
 
I'd call the firing pin/striker a fairly safe swap. By critical parts, I assumed you'd be swapping all springs - the trigger/connector spring being the one I'd probably be most concerned with causing a problem as a little twerk in it can cause reset/dead trigger issues in my experience. Not to mention swapping it more or less requires pulling most of the LPK guts out.
In that case, I think I'd be comfortable after standard function and safety testing.
 
In this case, I'd simply replace the firing pin and test it at the range once. I know the gun is reliable overall. No stoppages ever. This is a single part that broke. I'll replace it with another OEM Glock firing pin, of course. Take it to the range to confirm no problem... and good to go, I think.
As Caleb wrote, great blog post! Having been there, I was so glad that critical material failure in your EDC happened at the range instead of out "in the wild" where it might have been catastrophic! :oops:

I'm certainly not expert on the service life of OEM Glock firing pins and other critical parts, but firing pins, springs, etc. are relatively cheap and to quote that old friend I told you about yesterday, "they're a hell of a lot cheaper than a coffin!" So it would be interesting to poll some professional Glock armorers to see if they have a schedule of replacement of critical parts like we did in military and civil aviation. I wonder if that data are available from Glock or agencies that use them? :unsure:
 
So it would be interesting to poll some professional Glock armorers to see if they have a schedule of replacement of critical parts like we did in military and civil aviation.
Exactly!

With as much shooting as I do, I may also switch to another brand of range ammo with primers that aren't as "hard."
 
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I followed the Glocktalk thread and as far I go, I'd look at about 7k
rounds +/- to swap because most of the failures I've read about seem
to start at 5k and cluster between 10 and 12k. But the outliers have
gone to the 20k point prior to firing pin failure.

So it looks to me that "I" will, if I follow my own advice, need to swap
some of mine this fall because the shooting rotation on my stuff will
be at the 5-8k point on some of my guns.

I'm just glad I use hard cast bullets. otherwise I might needs barrels
in a while.

You did see the comment about shadow systems and their firing pins?
 
I followed the Glocktalk thread and as far I go, I'd look at about 7k
rounds +/- to swap because most of the failures I've read about seem
to start at 5k and cluster between 10 and 12k. But the outliers have
gone to the 20k point prior to firing pin failure.

So it looks to me that "I" will, if I follow my own advice, need to swap
some of mine this fall because the shooting rotation on my stuff will
be at the 5-8k point on some of my guns.

I'm just glad I use hard cast bullets. otherwise I might needs barrels
in a while.

You did see the comment about shadow systems and their firing pins?
Well using Racer's firing pin experience as another data point, it would seem that 7K rounds just may be a bit close to the threshold of a known failure. By way of example, in military and civil aviation, we typically use a 50% safety margin over the earliest know failure mode(s) for establishing limits of hours or cycles of "in service" use. The firing pin isn't very expensive and since I witnessed the material failure of Racer's EDC at ~7,400 rounds fired, if it were me, I'd likely consider using a 5K round count as my threshold for installing a new one. YMMV! :unsure:
 
Well using Racer's firing pin experience as another data point, it would seem that 7K rounds just may be a bit close to the threshold of a known failure. By way of example, in military and civil aviation, we typically use a 50% safety margin over the earliest know failure mode(s) for establishing limits of hours or cycles of "in service" use. The firing pin isn't very expensive and since I witnessed the material failure of Racer's EDC at ~7,400 rounds fired, if it were me, I'd likely consider using a 5K round count as my threshold for installing a new one. YMMV! :unsure:
For those of us who don't log every round fired, wondering the best approach. Thinking everyone would have a rough idea of rounds fired in general. If you assumed 100 rounds weekly, then that would translate into changing the firing pin annually - maybe along with the red dot battery? Adjust the math based on what you think you'd typically run in a week for that firearm.
 
Exactly!

With as much shooting as I do, I may also switch to another brand of range ammo with primers that aren't as "hard."
So, with the round count Racer has on this build, I'd be looking at two possible root causes.
1. A bad striker. If you know someone at the local university or a company that has a metallurgical lab to analyze the break for flaws.
2. Inspect the striker channel and see if rough machining could have caused the striker to fail.

Personally, I do not think the primer of your ammo is the culprit.

When you hear that term (hard) in connection with primers, it is a bit misleading.

So, yeah, there is a good bit of info available on rifle primers, less so on pistol primers. So, I'm using rifle data for this example.

The gun forums perpetuate "hard" as in physically harder and cite thicker cups and harder alloy as the means this is achieved. Is this true? Well, yes and no.

If you search around a bit on the web, you can find a chart with the cup thickness of all the popular domestic rifle brands. With one or two exceptions (Remington 6-1/2 is one) the thickness is fairly consistent within each size and type.

Yes, there is a difference in thickness between pistol primers and rifle primers, which is why with few exceptions, you don't swap them.
From what I can find, small pistol primers are .017" thick for all brands, standard and magnum.
Large pistol are .020" thick, standard and magnum.

The alloy used is basically the same as cartridge brass, which is 70% copper, and 30% zinc, or some close approximation. The cup needs to be ductile enough to keep from piercing, but other than that, I have been unable to find a reference to the hardness spec of the cup alloy. And each manufacturer likely has their own spec.

Rule of thumb is use the thin cup primers in cartridges like 22 Hornet and 30 Carbine.
The exception is the WSR. Myself, and many High Power shooters use these with no issue. I have seen first hand that Remington 6-1/2 primers will pierce in an AR though.

So, without industry insider info on what each manufacturer specs their primer brass stock, we'll never know for sure. But I'd wager that each thickness has its own hardness spec, but not multiple hardness specs for the same thickness. This is supported by the fact that CCI uses the same cup for their military spec #41 primers as they do for the 450 primer and change the anvil to decrease sensitivity. So harder? No, not in the physical sense. But most peeps say harder in relation to preventing slam fires in military type rifles, and they achieve that, just by skinning the cat a different way.


1706566231679.png


Here is a CCI chart which mentions the #34 and #41 primers have "NATO sensitivity". And this is how they achieve it.

CCI/Speer Technical Services says: "The CCI 400 primer does have a thinner cup bottom than CCI 450, #41 or BR4 primers... [with] the CCI #41 primer... there is more 'distance' between the tip of the anvil and the bottom of the cup." so that is their AR15 recommendation, although it seems like there are no complaints with using the BR4 and 450 primers by AR15 shooters and reloaders, in general. The #41 just gives you a little more safety margin for free-floating firing pins and would be the best choice for commercial reloaders who have no control over the rifles their .223 ammo is used in.

So, the #41 is basically the 450 primer with a shorter anvil. Same cup, same primer compound.

1706567392396.png
 
<<<Today, we are testing the Glock factory MIM Firing Pin against two Shadow Systems 17-4 Stainless Steel Billet Firing Pin to see which is more resistant to failure over time and use. >>>




I just ordered a Shadow Systems firing pin assembly and safety to try out. :)

But fear not... I plan on getting some good photos of the broken pin parts and the inside of the firing pin channel to see if there is any evidence of an out-of-spec issue in the slide. I'm pretty sure I won't find any. We'll see!
 
Interesting video and test. The relative durability is clearly demonstrated. I wonder how applicable it is to the use as a striker - i.e. the stress on the firing pin is a "punching" motion not the pin being trapped while the striker moves (assuming an in spec firing pin hole!) It'd be cool if they could figure out another stress test that mimics the interaction of the pin in the slide.
 
Interesting video and test. The relative durability is clearly demonstrated. I wonder how applicable it is to the use as a striker - i.e. the stress on the firing pin is a "punching" motion not the pin being trapped while the striker moves (assuming an in spec firing pin hole!) It'd be cool if they could figure out another stress test that mimics the interaction of the pin in the slide.
That would take a lot more repetitions... and a machine to do it.
 
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