Oversize Firing Pin Damage

Kiwi Mark · 09-01-2017, 05:59 PM

Most of you will know this, but a reminder wake up.
Shooter Lugers. Too long a firing pin will piece the primer and if it doesn't have post 1933 gas by pass cuts, on firing the high pressure blows the firing back as it has a seal. This compresses the firing spring, blows the firing pin retainer out the back of the breach block. Very Sad.
A friend did this and when mine wouldn't fire after the 2nd shot, I picked up the brass and knew what the problem was.
OK, remove blue, a spot of weld, then dress it up with the Dremel,
All my shooter have these 3 gas by passes cuts in them. Not hard to do.
Prior to this happen, I expected that there would be so much pressure, it would blow the sear bar out and do some really bad damage.

Mac Cat · 09-01-2017, 11:12 PM

I don't know much about firing pins - which kind are too long ?
(I don't shoot a lot, but the few times I had pierced primers was more about the reloads than the gun....curious)

Kiwi Mark · 09-01-2017, 11:29 PM

Even with factory ammo, if the firing pin sticks too far out from the breach block face it can piece the primer, that goes with any firearm. Lucky for me it was a 9mm and didn't cause too much damage, but a 308W may have been a different story.

ithacaartist · 09-02-2017, 02:11 AM

I've never heard of a firing pin tip that grew like Pinocchio's nose before. If it sticks out too far, something is significantly worn, either the inside of the breech block where the striker bottoms out, or the striker itself. I remember seeing a post about a piece of factory gauging that measured F.P. stick-out. It was basically a precisely cut notch on the end of the tool, and a piece of a credit card filed out just as precisely was deemed an adequate substitute. Somewhere here at Luger U., there is a spec for this notch, i.e. the precise distance the tip of the F.P. was designed to protrude. If it's excessive, you'll dress the tip to gain the correct dimension?

kurusu · 09-02-2017, 04:45 AM

Luger firing pins don't tend to be too long. It can happen of course but it's not common. The pierced primers, in a Luger, generally occur from excessive headspace.

Either from out of specs ammo, more common on the .30 Luger even with factory loads, or from a mismatched breech block that wasn't properly fitted to the gun.

rhuff · 09-02-2017, 01:57 PM

Perhaps I have misread Kiwi Mark's post, but I interpreted it that he found that he had too short of a firing pin in his shooter Luger(misfire X2), so he built up the tip of his firing pin with weld and then dressed it down with a Dremel tool......obviously leaving it too long, producing pierced primers when fired.

Kiwi Mark · 09-02-2017, 04:11 PM

Sorry, I'll explain. It's a 9mm, a very tired old lady, 1917 DWM and dressed up with some good looking grips. So off for a shoot, nothing done to the firing pin. Aftermarket mag. After 2 shots, it failed to fire the 3th. Picked up the fired brass, and I could see the pieced primers and could suck air through the case. As well as protuding too much, the diameter of the tip of the firing pin is 1.3mm. The spot of weld was added to the rear of the breach block where the firing pin retainer clicks back in it's final position as it had blow the very thin bit of metal out.
Luger manufactures started to do the gas blow back mod on the front face of the firing pin from 1933, 3 slots. Was it for this reason??

kurusu · 09-02-2017, 04:42 PM

Most probably. I only use Mausers as shooters.

DonVoigt · 09-02-2017, 06:43 PM

Here is what the gage looks like.
An original Kreighoff accepted gage, and one of my home made ones.

The min and max are in mm.

Thus the end of the striker(firing pin) should extend at least 1.1mm past the breech block face, and no more than 1.35mm.

DonVoigt · 09-02-2017, 06:50 PM

Quote:

Originally Posted by Kiwi Mark

Sorry, I'll explain. It's a 9mm, a very tired old lady, 1917 DWM and dressed up with some good looking grips. So off for a shoot, nothing done to the firing pin. Aftermarket mag. After 2 shots, it failed to fire the 3th. Picked up the fired brass, and I could see the pieced primers and could suck air through the case. As well as protuding too much, the diameter of the tip of the firing pin is 1.3mm. The spot of weld was added to the rear of the breach block where the firing pin retainer clicks back in it's final position as it had blow the very thin bit of metal out.
Luger manufactures started to do the gas blow back mod on the front face of the firing pin from 1933, 3 slots. Was it for this reason??

Actually the fluting started earlier, about 1930.
Its stated purpose was to improve striker performance in case of buildup of dirt/oil/powder residue; no mention of gas bypass.

Many think gas by pass is the "reason" for the flutes, see the recent discussion here:
http://luger.gunboards.com/showthrea...ighlight=flute

The surest way to improve gas bypass is to drill a hole in the bottom of the breech block, just aft of the spot where the striker stops against the inside of the breech- this is what the Norwegians and others did fora gas bypass.

Better yet is PM, inspection and correction of a sharp or too long striker nose(firing pin).

chr · 09-09-2017, 06:19 AM

Quote:

Originally Posted by DonVoigt

The surest way to improve gas bypass is to drill a hole in the bottom of the breech block, just aft of the spot where the striker stops against the inside of the breech- this is what the Norwegians and others did fora gas bypass.

Can you please add / post a pic of this drilled hole?
Thank you!

kurusu · 09-09-2017, 08:10 AM

Quote:

Originally Posted by chr

Can you please add / post a pic of this drilled hole?
Thank you!

I thought it was the Finns who used to drill the holes. But, I've been wrong before.

DonVoigt · 09-09-2017, 01:41 PM

Quote:

Originally Posted by kurusu

I thought it was the Finns who used to drill the holes. But, I've been wrong before.

Finns, Norwegians, Swedes- aren't they all the same? Northmen?

(My apologies to and of those folks who are members.)

chr,

There have been several pictures posted on various threads,
When I get a chance, I'll pull my Norwegian and see if it has the hole.

Maybe someone else has a picture handy or remembers where it is.

Maybe a search for "gas escape hole" would find it.

chr · 09-09-2017, 04:02 PM

Quote:

Originally Posted by DonVoigt

When I get a chance, I'll pull my Norwegian and see if it has the hole

Would be great. Thank you.

Goggle shows no picture.

kurusu · 09-09-2017, 04:22 PM

Quote:

Originally Posted by DonVoigt

Finns, Norwegians, Swedes- aren't they all the same? Northmen?

(My apologies to and of those folks who are members.)

chr,

There have been several pictures posted on various threads,
When I get a chance, I'll pull my Norwegian and see if it has the hole.

Maybe someone else has a picture handy or remembers where it is.

Maybe a search for "gas escape hole" would find it.

Well, they were all Swedes once.

DonVoigt · 09-09-2017, 08:18 PM

Quote:

Originally Posted by chr

Would be great. Thank you.

Goggle shows no picture.

Why would you expect google to have a picture?
Everything is NOT on the web!

Best I can do right now is describe it, it is an approx 1/8" hole, in the bottom of the bolt, on the centerline, just about at the edge of the "cone" on the inside that fits the front of the striker.

Did you try a forum search?

Probably not or you would have found this one:
http://forum.lugerforum.com/showthre...as+escape+hole

And another one, too bad the link is dead, but a good example of a Finn luger with hole!
http://forum.lugerforum.com/showthre...=bolt+gas+hole

Great example of why pictures should be hosted on the forum server too.

stg44fan · 09-09-2017, 09:46 PM

I believe this is the pic you guys are thinking of. From my understanding the hole is present on all Finnish Lugers just in case of a pierced primer.

DonVoigt · 09-09-2017, 10:29 PM

Quote:

Originally Posted by stg44fan

I believe this is the pic you guys are thinking of. From my understanding the hole is present on all Finnish Lugers just in case of a pierced primer.

Yes,
that is it. Thanks for posting the picture!

chr · 09-10-2017, 05:58 PM

Thanks to all.
I am thinking now to update my shooting Luger with this hole.

Gold idea or not, what would you say?

DonVoigt · 09-10-2017, 08:45 PM

Can't do any harm, as long as it is a "shooter".

09-01-2017, 05:59 PM	#1
Kiwi Mark User Join Date: Jan 2017 Posts: 23 Thanks: 0 Thanked 7 Times in 6 Posts	Oversize Firing Pin Damage Most of you will know this, but a reminder wake up. Shooter Lugers. Too long a firing pin will piece the primer and if it doesn't have post 1933 gas by pass cuts, on firing the high pressure blows the firing back as it has a seal. This compresses the firing spring, blows the firing pin retainer out the back of the breach block. Very Sad. A friend did this and when mine wouldn't fire after the 2nd shot, I picked up the brass and knew what the problem was. OK, remove blue, a spot of weld, then dress it up with the Dremel, All my shooter have these 3 gas by passes cuts in them. Not hard to do. Prior to this happen, I expected that there would be so much pressure, it would blow the sear bar out and do some really bad damage.

09-02-2017, 02:11 AM	#4
ithacaartist Twice a Lifer Lifetime Forum Patron Join Date: Mar 2011 Location: Atop the highest hill in Schuyler County NY Posts: 3,284 Thanks: 7,013 Thanked 2,478 Times in 1,320 Posts	I've never heard of a firing pin tip that grew like Pinocchio's nose before. If it sticks out too far, something is significantly worn, either the inside of the breech block where the striker bottoms out, or the striker itself. I remember seeing a post about a piece of factory gauging that measured F.P. stick-out. It was basically a precisely cut notch on the end of the tool, and a piece of a credit card filed out just as precisely was deemed an adequate substitute. Somewhere here at Luger U., there is a spec for this notch, i.e. the precise distance the tip of the F.P. was designed to protrude. If it's excessive, you'll dress the tip to gain the correct dimension? __________________ "... Liberty is the seed and soil, the air and light, the dew and rain of progress, love and joy."-- Robert Greene Ingersoll 1894

09-02-2017, 06:43 PM	#9
DonVoigt User Join Date: Apr 2015 Location: near Charlotte NC Posts: 4,677 Thanks: 1,439 Thanked 4,348 Times in 2,038 Posts	Here is what the gage looks like. An original Kreighoff accepted gage, and one of my home made ones. The min and max are in mm. Thus the end of the striker(firing pin) should extend at least 1.1mm past the breech block face, and no more than 1.35mm. Attached Thumbnails __________________ 03man(Don Voigt); Luger student and collector. Looking for DWM side plate: 69 ; Dreyse 1907 pistol K.S. Gendarmerie

09-09-2017, 09:46 PM	#17
stg44fan User Join Date: Apr 2017 Location: Portland OR Posts: 81 Thanks: 42 Thanked 49 Times in 27 Posts	I believe this is the pic you guys are thinking of. From my understanding the hole is present on all Finnish Lugers just in case of a pierced primer. Attached Thumbnails

09-10-2017, 08:45 PM	#20
DonVoigt User Join Date: Apr 2015 Location: near Charlotte NC Posts: 4,677 Thanks: 1,439 Thanked 4,348 Times in 2,038 Posts	Can't do any harm, as long as it is a "shooter". __________________ 03man(Don Voigt); Luger student and collector. Looking for DWM side plate: 69 ; Dreyse 1907 pistol K.S. Gendarmerie

09-01-2017, 11:12 PM	#2
Mac Cat Lifer Lifetime Forum Patron Join Date: Apr 2015 Location: Austin, Texas Posts: 672 Thanks: 2,012 Thanked 542 Times in 292 Posts	I don't know much about firing pins - which kind are too long ? (I don't shoot a lot, but the few times I had pierced primers was more about the reloads than the gun....curious)

09-01-2017, 11:29 PM	#3
Kiwi Mark User Join Date: Jan 2017 Posts: 23 Thanks: 0 Thanked 7 Times in 6 Posts	Even with factory ammo, if the firing pin sticks too far out from the breach block face it can piece the primer, that goes with any firearm. Lucky for me it was a 9mm and didn't cause too much damage, but a 308W may have been a different story.

09-02-2017, 04:45 AM	#5
kurusu User Join Date: Sep 2007 Posts: 1,225 Thanks: 2,679 Thanked 929 Times in 509 Posts	Luger firing pins don't tend to be too long. It can happen of course but it's not common. The pierced primers, in a Luger, generally occur from excessive headspace. Either from out of specs ammo, more common on the .30 Luger even with factory loads, or from a mismatched breech block that wasn't properly fitted to the gun.

09-02-2017, 01:57 PM	#6
rhuff Patron LugerForum Patron Join Date: Mar 2011 Location: Az. Posts: 2,270 Thanks: 2,686 Thanked 958 Times in 704 Posts	Perhaps I have misread Kiwi Mark's post, but I interpreted it that he found that he had too short of a firing pin in his shooter Luger(misfire X2), so he built up the tip of his firing pin with weld and then dressed it down with a Dremel tool......obviously leaving it too long, producing pierced primers when fired.

09-02-2017, 04:11 PM	#7
Kiwi Mark User Join Date: Jan 2017 Posts: 23 Thanks: 0 Thanked 7 Times in 6 Posts	Sorry, I'll explain. It's a 9mm, a very tired old lady, 1917 DWM and dressed up with some good looking grips. So off for a shoot, nothing done to the firing pin. Aftermarket mag. After 2 shots, it failed to fire the 3th. Picked up the fired brass, and I could see the pieced primers and could suck air through the case. As well as protuding too much, the diameter of the tip of the firing pin is 1.3mm. The spot of weld was added to the rear of the breach block where the firing pin retainer clicks back in it's final position as it had blow the very thin bit of metal out. Luger manufactures started to do the gas blow back mod on the front face of the firing pin from 1933, 3 slots. Was it for this reason??

09-02-2017, 04:42 PM	#8
kurusu User Join Date: Sep 2007 Posts: 1,225 Thanks: 2,679 Thanked 929 Times in 509 Posts	Most probably. I only use Mausers as shooters.

09-10-2017, 05:58 PM	#19
chr User Join Date: May 2017 Location: home country of the Lugers => Germany Posts: 13 Thanks: 3 Thanked 15 Times in 6 Posts	Thanks to all. I am thinking now to update my shooting Luger with this hole. Gold idea or not, what would you say?