Oversize Firing Pin Damage

ithacaartist · 09-02-2017, 03:11 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, 05:45 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, 02:57 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, 05:11 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, 05:42 PM

Most probably. I only use Mausers as shooters.

DonVoigt · 09-02-2017, 07:50 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, 07:19 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, 09:10 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.

09-02-2017, 03:11 AM	#1
ithacaartist Twice a Lifer Lifetime Forum Patron Join Date: Mar 2011 Location: Atop the highest hill in Schuyler County NY Posts: 3,401 Thanks: 7,561 Thanked 2,643 Times in 1,393 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, 05:45 AM	#2
kurusu User Join Date: Sep 2007 Posts: 1,225 Thanks: 2,679 Thanked 930 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, 02:57 PM	#3
rhuff Patron LugerForum Patron Join Date: Mar 2011 Location: Az. Posts: 2,315 Thanks: 2,748 Thanked 998 Times in 733 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, 05:11 PM	#4
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, 05:42 PM	#5
kurusu User Join Date: Sep 2007 Posts: 1,225 Thanks: 2,679 Thanked 930 Times in 509 Posts	Most probably. I only use Mausers as shooters.