Pierced primers LWD barrel

[steve896]

Gun is a 1st gen Glock 17. I am getting pierced primers with a Lone Wolf barrel I recently acquired, I do not get them with the factory Glock barrel. Around 12 out of a box of Rem. 115g were pierced. Also the primer strikes appear deeper on the rounds fired in the LW barrel (of the ones that wern't pierced). None of these were reloads, all factory ammo. Same trouble with another box of bullets. Called LWD and they will check out the barrel. Question is could I still have a a problem with the gun, I know the LW barrel is made to tighter tolerances, could the pressure be higher and causing this problem? I have to wait for the barrel to be returned to see whats happening, but if I should be checking out something on the gun I can look at it till then.
Thanks, Steve896

 

[Wildfire]

PSI.

Hey there:
This does kind of look like a PSI issue. The brass on the primer is flowing into the bolt at the firing pin hole. That would be my guess from your photos.
Unless there is some thing that you changed about the firing pin protrusion.
Looks like PSI to me.

 

[rcmodel]

I know the LW barrel is made to tighter tolerances, could the pressure be higher and causing this problem?

That is the only reason possible.

Just changing a barrel can have no effect on firing pin stike. It has to be increased pressure (tight bore & chamber) doing it.

Same trouble with another box of bullets.

By bullets, I guess you mean loaded ammo, as you said you were not reloading.
Was it the same Remington load as the first box, or another brand?

If it was two boxes of the same Remington ammo, could just be a bad lot of Remington ammo with soft primers.

Be sure and try another brand of ammo before you get too excited.

rcmodel

 

[tractorshaft]

Pierced Primers

Hi Steve,

I would take my slide completely apart, then under a magnifier inspect my firing pin, make sure it does not any little burrs or deformities on it. If you have some very fine rouge and a little buffing wheel I would gently buff and "Break" the edges of the somewhat flat sided Glock firing pin. It is supposed to be slightly rounded on the end, this helps prevent just what you are experiencing. You can find some nice articles over at Glock Talk, one of my favorite forums, next to this one of course. Let us know what the problem is would ya? By the way, the guys at Lone Wolf are top notch. I had a SS .357 SIG conversion barrel that was peening pretty badly due to a faulty heat treat and they sent me a brand new one via next day air. Just the best in customer service and great Glock products.

Jer

 

[rcmodel]

Doubtful it is a problem requiring a buffing wheel to the firing pin.

It isn't doing it with the stock Glock barrel.

rcmodel

 

[steve896]

Just to clarify, the ammo was all Remmington 115g fmj, but most likely different lots as they were bought at two different stores and probabably 6 or more months apart. i had also looked at the firing pin and it appears ok,no burrs or edges that dont belong. I did jump the gun and return the barrel (they were so accomodating over the phone to just send it back and they would check it right out). Didn't think to try another mfg product or run some reloads thru it. Duh!
Will update later.

thanks

 

[Jim K]

"Pierced" primers are not normally due to burrs on the firing pin or even a sharp firing pin. As Wildfire says, pressure (possibly combined with soft primers) is forcing the primer metal back into the firing pin hole, where it is sheared off when the barrel unlocks. (The other culprit is a relatively weak firing pin blow, so a stronger spring could resolve the problem. But if there is no problem with the original barrel, high pressure is the more likely cause.)

I strongly suggest that you remove the firing pin and check the firing pin tunnel for bits of primer brass; left in there, they could block the firing pin and cause a failure to fire.

Jim

 

[tractorshaft]

Gents,

Here is a related thread on the 1911 forum.

http://forums.1911forum.com/showthread.php?p=1808155

A burr or sharp edge on a Glock firing pin combined with "Known to be soft" Remington 1 1/2 primers or "Borderline" hot loads can indeed cause "Pierces" that would not occur in other model handguns. The condition is then compounded as the hot gases pit or further contribute to the "Rough" condition of the end of the firing pin whereupon the condition exacerbates itself, I have seen this happen. Take particular note of the rectangular shape of the firing pin imprint of a Glock vs. a SIG, Colt, Springfield, S&W , it is self-explanatory and most unique in shape comparatively speaking.

It is simple physics that a sharp corner exerts more direct force in a given area than a rounded shape does; EG: Ram the end of a baseball bat against a piece of tin and look at the imprint it leaves, it bends the metal but does not penetrate it, do the same thing with the end of a crow bar and see what happens, my point exactly, no pun intended.

I submit for your inspection;

The Glock firing pin, rectangular with a rounded end, possessing 2 potentially "Sharp" edges whereas a 1911 or other style pins being completely cylindrical and "Rounded" have none, the others by design, are less likely to suffer from which we speak. Having said that, in this case I do suspect only the primers, even the time tested 1911 firing pin design was putting a hole in the ones referenced in the above link, or visa versa;

There are 2 possible outcomes:

If the result confirms the hypothesis, then we have made a measurement. If the result is contrary to the hypothesis, then we have made a discovery.

Best regards.

 

[Jim K]

I will only say again that pitting, corrosion, or "sharpness" of the firing pin rarely has anything to do with "pierced" primers. They result from a firing pin that does not have the momentum to resist the internal pressure in the primer and so lets the primer metal flow back into the firing pin hole. If the primer is fully punched out, gas can enter the firing pin hole and erode the firing pin, but the erosion is the effect, not the cause, of a blanked primer.

Jim

 

[steve896]

The firing pin tunnel is clean,no bits of brass. The firing pin is the newer double slot design, but the tip appears more flat than rounded off . I will change out the firing pin spring. I should probablly change out the firing pin too if its supposed to be more rounded. Tried to get a close up pic of the firing pin, couldn't focus close enough to see anything.

steve