.40 S&W primers with firing pin swipes I didn't expect. What's wrong? (PIC)

nitesite

nitesite

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Glock 22 3rd Gen

Zero Bullet 180-gr JHP
Unique 5.3 grains
Win Small Pistol primer
OAL 1.127

VG accuracy @ 25-yards. No signs of swelled brass or GLOCK bulge. Primers not overly flattened. Just the darn FP swipe that is bothering me.

Is there something I am overlooking or could it just be the gun?

40S_W-Primer-Swipe.jpg
 
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Mine does the same thing. I think it has something to do with the breechface/firing pin hole.
 
That sounds like a awful light load for a 180gr JHP, the upper end loads would be 6.5-6.7grs of Unique. But that aside I'd probably look at replacing your striker and recoil springs.
 
Mind does it with factory ammo too, its not unique to reloads. And you should see the primer after I use a piece of dead brass to dry fire with ;)
 
What you have pictured is the Glock firing pin picture.

So yea, no biggie, just the Glock thingy. You can always tell "Glock brass" this way.
 
When I saw the title I knew it was concerning a Glock before I even read the post. All mine do it, it's just the way they are. Don't let it concern you.
 
Am I the only one here who is seeing pierced primers? At least that's what it looks like to me. The primers appear to be torn as they were dragged down over the firing pin. And if these are Winchester primers, they're the older plated style which are pretty tough. For reasons I don't fully understand, my Glock 21 suddenly started piercing primers and the result was erosion around the firing pin hole in the slide.

Dave Sinko
 
It's me, nitesite, original thread starter again. :)

Okay, let me back up a bit here. As the owner of other GLOCK pistols and an avid reloader, I am very aware of the rectangular mark left in the primer because of the breechface cut for the firing pin. That mark is not what I am asking about.

It's the upward swipe "cut" by the firing pin as the barrel tilts.

I have no recollection of the firing pin swipes from my G34 and My G29 ammo both factory and reloaded. I've seen these swipes before in some of the brass I've scrounged, just not in brass from MY guns.

If the FP swipes were in a nice 1911, I'd be wondering what was causing this condition. If I'd seen the FP swipe in my other GLOCKs then I probably would not be asking the question.

One final thought. I have a helluva lot of guaranteed once-fired .40 S&W Winchester brass. Looking at a large sampling of them the majority are from a GLOCK. And a FP swipe is "barely there" on less than 20% of them, and never comes near the edge of the primer pocket.

So I'm looking for your ideas as whether it is a timing issue, pressure issue, or if it's just a natural occurrence for most (if not all) GLOCKs and I'm just missing it..

Oh, and David Sinko... I you're a bit off on your observation. The primers aren't pierced. But you're 100% correct that they are older WSP primers! Good eye!!!

Edited to add:

I think I'm going to remove the firing pin and spring and clean the firing pin channel, to see if any crud is hindering the pin from retracting fast enough. Maybe that's all it is. Just thinking out loud....
 
Last edited:
IIRC the swipe is from the firearm unlocking from battery before the firing pin is fully retracted into the slide.
Basically the pin is still in contact with the primer as the action starts to unlock.
I do not have or never had a .40 so no experience with it.. What I stated above is something I read years ago when the .40 first came out.

I also saw this in fired brass from other handguns besides a Glock.
 
Those are called drag marks left when slide/barrel comes out of battery and the firing pin is still protruding from the breechface. Completely normal and Glocks aren't the only guns that do this.
 
If the mark is from the striker dragging three things come to mind

The striker pin channel is dirty

The striker pin spring is weak

The recoil spring is weak, allowing the gun to come out of battery to soon.

If the pistol is unloaded and not cocked if you shake it does it rattle?

How many rounds through the gun?
 
I'd say 90% of glocks do this. Completely normal.
Click to expand...

Yes, but the picture looks a little bit more than normal.

The other thing is in the photo the primer hits look off center. The only time I have seen that is when the gun didnt go fully into battery.
 
I had a Taurus do the same thing. I cleaned out the FP channel and replaced the striker spring and the return spring. Cleared my issue up, although I can't say which part actually fixed it...
 
I don't know about Glocks, but that's a big no-no in a 1911. The firing pin is not retracting before the barrel unlocks. It can lead to broken firing pins in 1911's, and I suspect the same thing could happen in Glocks. I can't see why someone would design a system that would put extra stress on the firing pin tip.

If the gun is tossing the empties further than it had been, a stronger recoil spring is in order. Otherwise, get a stronger firing pin spring.

Buck
 
I will agree that weak springs are likely what is causing this. I reduced the recoil spring weight of my 21 to shoot sissy loads at USPSA matches and never compensated at the firing pin spring. Shooting full power ammo with certain unbalanced spring combinations is not advisable and is probably what caused my pierced primers. I think you should change both recoil and firing pin springs with new stock parts and see what happens. And you should check the tip of the firing pin to make sure it's not pitted. Even one pierced primer can cause pitting and lead to much worse problems.

Dave Sinko
 
Found part of the problem...

Thank you all for your comments and suggestions. I decided that my issued sidearm might need a good cleaning of its striker channel, so I disassembled the slide. There was a measurable amount of "schmutz" which seemed to be oil or solvent and particle residue. The striker didn't slide freely, but after cleaning it now does.

But of particular interest was what I discovered on the nose of the striker. Here's a pic.

GLOCK-striker_nose.jpg


Think I might have narrowed down the cause of my concern?????
 
I have a Taurus PT140 Millennium Pro that does the same thing. I did not condider this a problem. I found this an interesting question and discussion.
 
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