Firing pin cracked
 

I was not sure where to post this, but I figured it would fit here.

I bought a Luger to shoot. I took it completely apart to make sure it was OK to shoot, and to clean it (like most guns I buy, it was filthy inside). Anyway I got the firing pin out and cleaned all the gunk off and boy was I glad I did. Take a look at what I found - I'm glad I didn't shoot it like that!

So now I have to get a new firing pin, but I'll keep the cracked one because it is a numbers matching gun. Just the finish is worn to about 80%.

- Geo

over powered ammo!!!
 

:eek:Thanks for the post on the faulty pin... but, it would have broken, and just failed to fire, as the firing pin spring would push the rear part back...hence, no spring tension, no snap to the primer.... !!...:eek:... I have original, WW1 & WW2, replacement firing pins available for $35.00 let me know if I can be of help... Other than me, Lugerdoc can certainly take care of your problem!!... best to you, til...lat'r....GT:cheers:

Btw....
 

Follow up note! No disrespect intended, but, that is one ugly ass firing pin to start with??..:jumper:. Never seen one that crude... looks hand made?... Let me know if I can help.... GT....:cheers:

As my wood shop teacher was so fond of saying (to me): "I could do better work with a chainsaw..."
dju

This firing pin does look weird. The front end appears to have no problem, but the rear, unrelieved portion of its cylinder has been doodled with, filed, smoothed off, or whatever, with a file, maybe to remove a burr--though how one would develop there in the first place is a mystery.

This pin has the fluting cuts of a WW-II Mauser firing pin. That's quite a battering it's taken. Something hard and sharp has been rubbing that firing pin. How does the rest of the action, receiver and frame look? What does the sear lever look like? In failure, if it were cocked with a round in the chamber, and the front end of the pin separated from the sear portion, you would have had a discharge. That's one good reason for always keeping a firearm pointed in a safe direction!

The front and middle sections look engine [lathe] turned; the ass end looks quite a bit like the Luger-style barrel bands that I do using an end mill and my rotary indexing head...

...Reinforcing Gerry's comment about it looking crude/hand made... :)

The presence of a serial number ending, if size and font correct, would indicate that someone tried to repair the original firing pin by turning a sleeve that was added to the rear of the original FP. Poor adhesion technique or other factor might have later cracked the FP at the repair joint.

The pin is from a Nazi reworked 1918 Luger. The serial num matches and is same font as the other reworked parts (grips and toggle axle). I too have never seen one so rough.

The rest of the gun looks fine as far as mechanical condition.

GT - thanks for the offer - I just found a repro firing pin in my box of stuff, so OK for now to shoot it.

Interesting point about it being repair job - because the front part looks just fine and original, but the back part is messed up. There is nothing I can see that would cause such rough wear to the pin. The pin was cold blued so that is why it looks so clean after I took the blue off. Someone may have blued it to cover the repair.

- Geo

Marc - "That's one good reason for always keeping a firearm pointed in a safe direction!"

I always do. I have had unexpected discharge from guns I was holding a couple of times in my life. Not fun.

Same here. I had a wartime P38 discharge when I used the de-cocking/safety lever. Fired a round into the inner door panel of my Chevy station wagon. Interestingly, the 9mm bullet did not penetrate the outer door skin. It hit a window riser arm and left a dent, but did not impede function of the window riser. I took the door apart when I junked the car, but couldn't find the bullet...

I no longer trust slide safeties or de-cocking levers on any pistol. :thumbup:

Learned early on to distrust them P 38s.

I put a round into the floor of the old farmhouse I was raised in.

I was 16. My Grandmother was not pleased.

Ithacaartist, IIRC, the firing pin spring does not push back on the rear of the firing pin. The spring pushes forward on it, fitting inside the cup at the back of the pin. The sear bar holds the pin back by engaging the part that sticks out sideways, but the spring always is pushing the pin forwards. That's how a faulty sear can cause chainfire, with nothing to keep the pin from riding with the bolt forward.

Yes, annnnd no.....
 

Hi Alex, you are correct in the observation that the spring pushes forward on the front of the firing pin.... but, it also pushes back... so, what does that mean you might ask... well, we are all assuming that two things are going to occur at once, and that is that the pin is going to just randomly break from a static position, and secondly, once broken the spring would exert enough tension to slam fire like an open bolt type set up... well, here's what really happens, (disclaimer, MOST of the time!! Anything is possible!)... The pistol in normal cocked firing position shows no indication of a pending malfunction... you fire the shot, the breechblock locks closed and the firing pin falls as normal, and the gun goes off. Upon discharge shock, is when the failure occurs, and upon recoil the pin separates. so the front half of the now two piece pin stays forward in the front half of the breechblock, while the rear part goes back normally into what used to be a cocked and as yet disconnected position... The Breechblock comes forward, but the firing pin spring being 100% extended, (WRONG! it is compressed as normally contained, but not cocked) just closed on the loaded chamber as it would normally??? But, no click, no bang?? That because the spring is pushing back on the rear half (WRONG! pushing back on the retainer, same result, wrong terminology!) as well as pushing forward on the front half....:eek:... it would seem it should go off, but it doesn't??? It just doesn't have enough spring tension to overcome the primer skin... Now, that being said, I would bet anyone's life on it, but after have two failures of this type with the very same results, I think the chance of full auto or additional discharge are remote...:thumbup: (Thank God, or it would certainly have happen to me!!:eek:) Best to all, til....lat'r....GT:cheers:

I still don't get how or if at all the spring is ever pushing back on the firing pin.

What part of the firing pin is the spring ever pushing "back" on ?

There is only one coil spring for the firing pin, and it fits into the firing pin's cup at the rear. Inside the bolt, the pin is inserted from the rear, then the spring goes in, then the spring is trapped between the firing pin and the spring retainer, which bayonets into the bolt at the rear. The spring can't pull the pin back, because it is not attached. There is no other spring to push back on it. Even if the pin broke in half, there would no way for the spring to be pushing any part of the firing pin back towards the rear of the gun.
No ?

My comment on the chain-fire phenom was not really to the point of the OP, .... I just threw it in to elaborate on the spring thing.

Axl,
You are correct. If the rear area of this firing pin had sheared off, the gun would have fired from pressure pushing the balance of the pin forward, not back, since the firing pin retained is held fixed inside the breech block. The rear portion of the FP may have been held by the sear, but the front portion would have traveled along with the breech block and caused a slam fire and most likely a full-auto dump since the FP would have protruded from the breech block under spring pressure.

Gerry, I think you should hacksaw a firing pin and videotape the demonstration! Inquiring minds want to know! :thumbup:

...With a full magazine... :)

...Just use a Nambu... no hack saw necessary... (sorry I just couldn't resist!) :D

firing pin failure...
 

Hi Alx, and Alanint, and all... you are correct in that the spring pushes back against the firing pin retainer when fully compressed and with an un-broken pin... I was over generalizing on that point, as I only meant to illustrate that the rear half of the pin stays back with out the ability to utilize any type of energy to go forward, (my bad!)...... as in, the part, of the now two piece pin, with the sear notch won't go forward, whether held back or slid back, as it has nothing to propel it?? (CORRECT) The back half has essentially become a notched tube... But, you are incorrect when you state the spring pushes ahead on the forward part of the broken pin. (WRONG, I was incorrect! it still has some preload) In essence, with a broken pin, it is fully extended, un-contained, (WRONG! has some tension) and pushes or hold the front part forward. (CORRECT) with a broken pin it has far less preload then with a good pin and cocked? ...Now, if we can see the same thing on what is posted above, (I NOW SEE YOUR POINTS, CAN YOU SEE MINE?) :) you then will see the rest of what I describe is correct. The gun will not fire, because of the (NEAR) full length spring does NOT exert enough force on the front part of the pin, and there is little kinetic energy (1/2 pin, (NEARLY) full length (SLIGHTLY) compressed spring? Short pin movement, maybe .050"?), to ignite the primer when slammed shut.. also, you will not hear any click as there is NO mechanical movement of any, or either, part of the firing pin, as it is already either fully pushed forward under WEAK spring tension, or held back by the sear because of no spring tension against the rear half of the broken pin?? (sear bar moves, back half of the pin doesn't.... ) So, in essence, the FP spring becomes a shock absorber of sorts, (CORRECT) allowing the front part of the broken pin to push back slightly, instead of denting the primer cup... NOW!! If the firing pin breaks irregularly, and for some odd reason, a shard of broken pin jams the forward part of the pin fully into the breechblock, then we have a different animal entirely!
So, I still maintain, the gun will not click, and the round will not fire in the vast majorities of firing pin full separation failures.. :eek:.. BTW, both pins I had, broke in half at exactly the same place.. righ in the middle where it was numbered, and both were WW1, and, to make matters worse, each time, I cycled the gun several times to try and get it to work thinking it was a common sear or trigger lever issue... Nothing I tried would make it fire!!... Had to put a pin in it... plain and simple... "Nothing is ever as it seems!" :) Best to all, til...lat'r....GT:cheers:

Interesting. I would have guessed it would work like the independent firing pin on an MP40 Bolt and fired the cartridge via inertia, at least.

" In essence, with a broken pin, it is fully extended, un-contained, and really pushes on very little, if anything at all... "

This is not making sense to me .... When assembling the firing pin into the gun, and compressing the spring with the retainer, there is quite a bit of pressure, even with the pin all the way forward, sticking out past the bolt-face. Even with a broken firing pin, broken in half, there is no way the metal can escape being there .... the stack of firing pin pieces is the same length as before, or longer if the break is jagged and the forward part of the pin twists. If the skirt of the cup is what is broken off, and the sear bar holds back the rear part of the pin which is merely then a sleeve, the front of the pin is still under the spring pressure.

Given that the spring would not have enough pressure to dent the primer cap at rest, still the intertia of the bolt slamming the primer with the pin's point could cause firing. Without the sear holding back the entire pin when the action closes, you have a dangerous situation. But if the pin were broken in half, with the break in front of the spring cup, and the gun went into battery with the sear holding the back of the pin as it is supposed to, there might not be enough inertia for the front half of the pin to fire the gun. Maybe that is how your pins broke, and why the gun did not fire.

That was my feeling. Somewhat like an MP40 bolt setup.

OK, well. somebody will try it with just the front end of a firing pin installed, and we'll see. I think it will fire.

yes....and no....
 

Hi guys, well I was working on memory and so, just went to the bench to see if I could determine what actually happened at the range... here's what I found out at the bench.. I took out all my firing pin springs that I have in stock, a dozen plus... and I find that there is a 3/8" variance in free length between the longest and the shortest... I don't know if this would factor in, but you again are correct that there is some spring pressure even with the broken pin and shortest spring... although still nothing like the tension power of the spring tension when compressed approx. 3/8"with a good firing pin locked on the sear notch...But, again, the broken firing pin is not pushed, or released, (or held) by anything?? The breechblock carries it, but does not allow the transfer of inertia necessary for the now, less than half as heavy firing pin, to strike from near zero forward movement ?? To further complicate things, I think the loading case rim, is pushing the firing pin back flush before it ever goes into battery, thus simply resting, sliding, against the primer throughout the whole chambering process?? Otherwise I believe, it, (the cartridge) would jam against the protruding pin point?? At any rate, it didn't fire for me on failure, and on the next round, or the next?? On two occasions... :eek:.. next one might go off.. but I really hope we never see that!..... It was an Erfurt! Might have been the whole issue... BTW, one of the pins broke right smack dab in the middle... almost as if cut... I'm sorry to say, I can't remember if it marked the primer at all, like an AR will sometimes do... I looked, just can't remember... it was WW box ammo... Get out your hacksaws boys! :cheers:... Best to all, til...lat'r....GT:jumper: BTW, An MP / Uzi, anything bolt is probably 100 times, or more, the mass of a complete Luger firing pin, with a rock solid pin point, and it's coming in, all the way from center field!!!... BTW, David, I'm betting it don't! :) lets set up a pool!

broken pins
 

Hi Alx, In reading more of your post, I think the reason for the breakage might be two fold, and some of it my fault... the first time, it broke immediately and may have already been fractured, and other then being numbered, old dark and dirty I have no idea.. the second pin broke right thru the number as well, but I was shooting 9MM NATO ammo and was having all kinds of issues until the firing pin broke and the day was done... It wasn't visibly broken when I started and I had looked at it upon a prior inspection. it was a matching gun too! I just don't trust any / all junky WW1 firing pins anymore... :cheers:... best to all, til...lat'r...GT

test proceedure!
 

I have an idea, (dangerous all by itself!) :eek: which I will try later this week..... I am going to the range, and will remove the sear bar and hold open.... then with one round in the mag... pointed down range, I will release the toggle and see if it goes off, and if I was just lucky! Or otherwise...:eek:... best to all, til...lat'r...GT:cheers:

Let's hope we don't have to start calling you "one eye", GT!

Good luck! It should be an interesting contribution to Luger lore!

courting disaster??
 

Hi Alanint, yes! I am wondering the very same thing.... will the mass of the full firing pin make a difference??... I don't think so... but I am worried! Maybe should have a camera ready for the surprised look that will most likely be on my face!!...:eek:... :)...best to all, til...lat'r....GT

BTW, I'm also going to try it with a cartridge in the chamber for a direct head on strike? Maybe negating the scrubbing effect of loading.... :eek:.... interesting if nothing else! :jumper:

I have the impression that Luger in full auto mode will empty its full magazine in what appears to be one slightly prolonged instant, all one sound .... the fastest machine gun after a MGxx, Hugo and Georg having basically adapted the Maxim machine gun action for semi-auto ....

fast & full!
 

Yes, if it does go off, with a full mag...it would be uncontrolled mayhem...but as I'm only going to use one round at a time... Even I should be safe???... to a degree....:)...til..lat'r...GT

My Money says that GT's experiment will not result in a slamfire...

I think the the firing pin would need the momemtum of a sudden full fall powered by the firing pin spring to result in a discharge with a locked breech.

If the front portion of the firing pin is broken free of the sear surface, I think that when the breechblock slams home, loading the cartridge from the magazine on it's way, that the firing pin spring will actually cushion and soften the blow of the firing pin and a discharge could not be depended upon... UNLESS you are using reloads with civilian grade small pistol primers... sealed Military primers take a good smack to set them off.

Just my $0.02 worth of mechanical engineering experience... take it or leave it. The test will tell the story.

Uh, Oh! G.T., break out those soft commercial pistol primers. We want to hear a bang!

GT,

If you want to do it the safest way possible, then just resize some fired 9mm brass, and prime them with a fresh primer. Then you can chamber it with the toggle open, and allow the toggle train to slam forward. No powder or projectile to worry about. If it pops the primer, it would fire the cartridge. You could do this in your shop. Just a thought.



PS...If you can't resize fired brass, then just remove the bullet and powder from a loaded round. The result will be the same.

Gerry, as you indicated in your story, sometimes it would fire, but mostly not? I wasn't intending to say that it would be rock-solid dependable ignition under these circumstances, but I'd estimate it to be at least as dangerous as dropping a de-cocked Luger.

A handy way to replicate the broken firing pin might be to snag the front half of one that's been on eBay, listed without mention of its condition as original f.p.! Using the entire firing pin might be tipping the scale to the "bang" side.

Releasing the action on the chambered, primed-only round sounds the safest way to go. It would avoid eating up the energy needed to strip the round from the mag and scrub it into the chamber, again, maybe a tip of the scale towards a bang.

You know, I hope we're all a little bit right--that dropping the toggle, say, a dozen times, it will have gone off a couple of times. It's like Xmas morning, waiting to see how this experiment turns out!!!

GT, As I understand it, you are using a FP that doesn't catch on the sear (trigger bar). THis could be caused by either of these part being worn or damaged. In most cases, this alone would not cause the pistol to slam fire. Tom

Range test tomorrow!!!!
 

Hi Tom, well sort of.. our thread is about a firing pin that broke in half and caused the weapon to just not fire??.. our discussion stems around the issue as to whether or not the weapon could have discharged from slamming home with a broken in half pin, the second of two such failures I have experienced.. neither time could I make the weapon go off by re-cocking and reloading until I discovered the broken pin... Maybe I was just lucky...we will see tomorrow as I try to replicate the failure by removing the sear bar, and just loading one round in the mag at a time... BTW, drop me an email, I need to inquire about some of the items you have mentioned... and some others I need! best to you Tom, til...lat'r....GT....:cheers:

Range report!! Range report!!!
 

Well, just got back from the range and my test fire with the sear bar removed, toggle slammed shut, produced NO slamfires!!! out of 10 attempts, :eek: and I think with 99% certainty, that it will not go off with a separated firing pin, as long as the front part isn't lodged in the breechblock for some un-known reason?? I also tried it a few times with a cartridge in the chamber and a direct impingement of the pin on primer in a slam fire condition, same results.. no bang.. BUT, it did mark the primer in every instance, just as I surmised with AR type firearms... So, there you have it boys! Can't go off unless the firing pin drops from a sear release.....:)...Best to all, til...lat'r....GT:cheers:

Good work, G.T.!! Thanks for the ed-ju-macation!

range test!
 

Hi to all! I was kinda surprised myself?? I had the prior experience of the failures, or I would have thought the same way.. And, again, nothing to ever take lightly! I think a large % of inadvertent discharges, come during, or just after a malfunction..:eek:.... Sooooo, always keep it pointed downrange!! BTW, I would have tested more, but the range officers were starting to look at me with a puzzled expression?? Thought it time to move on... :).. Best to all my forum friends! til...lat'r....GT:cheers:

:cheers:

Ahah! My theory is vindicated! :thumbup: :rockon: