Nearly shot my friend from defective pistol...

The earliest Walther P-1s (not those with the P-38 slide) had a very similar problem. Someone found that if you modified or removed the hammer block, when you used the hammer drop/safety it would fire fully auto till the clip ran empty. It was modified on later models to make this nie impossible but there are still some on the used market that were screwed up and just waiting for some new owner to try to safe it.

If you're ever buying a used P-1, make sure that you test the safety before you load a full clip.
 
I would believe that the firing pin was jammed with the tip protruding through the breach face. this cause the weapon to slam fire. In the future, realize that the weapon has a machanical failure and most likely it is not the ammo. I have seen this happen to a PPK/S. I had a G17 that went full auto for three shots in a match. It was a timed match and the shots were recorded. Less than .1 seconds between them! It was a used Glock that someone had tried to do a"trigger job" to. Every time you clean your weapon, inspect the breach face and firing pin.
 
Blackhawk- yes racking the slide with my finger not near the trigger would send the gun firing away. If I did the same thing with out a clip or ammo in the gun the hammer never dropped. I never tried it with an empty clip in it. Well I am send ng the gun off to day to EAA for repairs.
 
Mantis,

Thanks. That gives a whole new dimension to why I really, REALLY prefer DAO autos for HD or SD use. SAs are fine for the range where you'll never need to rack the slide unless the gun is pointed somewhere truly "safe".

Innocently cleaning, loading, and racking the slide to chamber a round into your "nightstand" gun or CCW could be an immense disaster if it goes FA! :eek: :eek: :(

Yours is what I'd still consider a NEW gun -- broken in with 700 rounds, but still a new gun! :eek: :eek:
 
I am assuming that you had the gun pointed downrange? Doesn't sound like it from your description of shooting the ground near your buddy. Downrange. Always downrange.

Had a 1911 "go off" without any apparent reason once. Only fired one round. that was enough to scare the bejesus out of me. Didn't do a whole lot for the carpet, either (at least it was in a safe direction). Gunsmith never could figure out why it discharged. Suggested possible sensitive primer on older military surplus ammo.

Had a friend whose brand new AR 15 went full auto right out of the box. Did it for first three magazines and then stopped and never did it again.

My dad was in a hunting party in the early 1950s where a hunter leaned a loaded semi-auto shotgun against a car fender. It fell and emptied itself when it hit the ground. One of the men in the group was killed.

Strangest full-auto incident I ever heard about was an old Colt Single Action Army that would go full-auto. Yes, it can be done but it requires two specific conditions to exist in order for it to happen. The firing pin bushing was missing. When it fired the primer was actually blown out of the pocket back into the hammer with enough force to cock it. The second problem was a broken sear. So when the hammer was driven back nothing stopped it from falling forward again and the process repeated until the gun ran dry. A full-auto SAA.
 
Wow, must have been hairy.

I bought it new in March and have put 700 rounds through it. As soon as I racked a round, it went full auto.
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Have you cleaned the firing pin channel at all? May very well be a bum sear or suuuper worn face on the hammer notch?

Imagine finding out about this problem at home :eek:
 
Blackhawk- why wouldn't a DAO go full auto if you racked the slide? I don't know much about firearm internals.

SaxonPig- The rapid fire of the gun pulled my hand to the left and up at my friend. I was in shock and didn't have time to react. It was pointed in front of me at the ground(I was outside).

krept- I only dismantle the gun how the manufacturer suggests for cleaning. I have no idea how to clean the firing pin channel. I just use a tooth brush and solvent to clean all the parts in the grip and slide I can't reach with swabs.
 
Saxonpig, I enjoyed your story about the full auto SAA. I hope you get everything figured out and fixed Mantis.
 
Mantis,
why wouldn't a DAO go full auto if you racked the slide? I don't know much about firearm internals.
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On a DAO semi, the firing pin is kept in the retracted position by the firing pin spring, which has the strength of a front suspension coil spring from a '52 Buick Roadmaster or close to it. Additionally, the hammer is NOT cocked. To fire, the hammer has to be cocked by the trigger motion and suddenly released without ever remaining in the cocked position. The hammer spring has to impart enough velocity to the hammer so its momentum plus the energy the hammer spring still has can overcome the firing pin spring to allow the firing pin to move forward to strike the primer.

The answer to your question is because the hammer can only be cocked by pulling the trigger and the hammer can never remain in a cocked or "almost" cocked position without the trigger being pulled.

OTOH, an SA or DA/SA pistol can have the hammer remain in the cocked position either by manually cocking it or by the action of the slide from racking it or cycling from the previous shot. All that has to happen for a cocked pistol with a chambered round to fire is for the hammer to be released, and there can be any number of parts failures that can cause that in addition to pulling the trigger.
 
Blackhawk,
A DOA can go auto if the problem is the firing pin. If it is jammed in the position where it is protruding through th breach face. It has nothing to do with the hammer. The forward movement of the slide causes the firing pin to strike the primer as the cartridge is chamered. This is a slamfire.
 
True - almost any semiautomatic can have the semi removed from its description due to different parts failures. And as SaxonPig pointed out, under a bizarre set of circumstances, even a revolver can go full-auto. I have heard the same account as he related - seems plausible
 
I took the 9mm back to where I bought it and it is being sent to EAA to be repaired under warranty. I plan to trade it off for a 9mm berreta or an AK-47...Decisions, decisions...
 
dj1726,
A DOA can go auto if the problem is the firing pin. If it is jammed in the position where it is protruding through th breach face. It has nothing to do with the hammer. The forward movement of the slide causes the firing pin to strike the primer as the cartridge is chamered. This is a slamfire.
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RE: jammed firing pin. Great big if, that I classify as a highly improbable possibility. Are you aware of any documented occurrence? See the next paragraph, though.

RE: nothing to do with the hammer. It has EVERYTHING to do with the hammer. A firing pin by itself cannot have enough momentum to overcome the firing pin spring regardless of the speed of the slide. It would, however, be relatively easy to jam a firing pin in the extended position by deliberately forcing it into the firing position and tightening its retaining set screw to hold it there. But that's the result of somebody deliberately tampering with the pistol.

RE: slamfire. True. A slam fire is when the slide's momentum causes or permits something to ignite the primer. That's not going to happen with a DAO because the hammer never loses contact with the firing pin unless the trigger is pulled, which prevents it from gaining enough momentum to overcome the firing pin spring. Different case with a DA/SA because the hammer is held in the cocked position after the slide cycles. If the sear cannot hold the hammer due to wear, etc., it can gain the required momentum to fire as soon as the slide closes the action.

My bet with Mantis' gun is that the sear is dysfunctional, probably due to improper adjustment. Since it's been sent back to EAA, we'll probably never know!
 
Saxonpig,
Strangest full-auto incident I ever heard about was an old Colt Single Action Army that would go full-auto. Yes, it can be done but it requires two specific conditions to exist in order for it to happen. The firing pin bushing was missing. When it fired the primer was actually blown out of the pocket back into the hammer with enough force to cock it.
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That's something I'd have to see to believe! The primer ignition hole in the casing is very small compared to the primer diameter. That means there will be a great pressure drop (Bernoulli's Principle) from the powder side to the primer side, so it's not even likely that the primer will be blown out at all.

Secondly, the primer mass is very low and its impetus will be zero after it travels the length of the primer hole in the casing. Due to low mass, its energy will be rapidly dissipated when it hits anything at all much less a hammer held forward by a strong spring.

I wonder if the "gun legend" you heard (like an urban legend) originated among wenching soldiers, fishermen, or cowboys.... :D
 
Blackhawk,
Like I wrote in my earlier post, I personally know of a Florida Marine Patrolman that had a Walther go full auto because of of a dirty firing pin channel and IT HAPPENED TO ME DURING A MATCH! My Glock went full auto because of a bad "trigger job." I had bought the gun used and was trying it out at a match at Shooting Sports it Tampa a few years ago. Fired three shots with one trigger pull. Most semi autos can not go full auto with out damage to the firing pin or firing pin safety. The internal passive firing pin safety would prevent a pistol from going full auto. As you pull the trigger, the trigger bar moves to the rear and depresses the passive firing pin safety. The hammer then fall on the firing pin, the firing pin moves forward and strikes the primer. When the slide recoils to the rear, it resets the trigger. On most of the various makes, this will reactivate the passive firing pin safety. This means that if the firing pin is struck by the hammer, it still could not contact the primer. The firing pin would strike the safety block. The easiest way to see this is on a Beretta 92/96. Make sure the weapon is unloaded and pull the trigger, watch the firing pin safety (visible on top of the slide in front of the rear sight). As you pull the trigger, the block moves upward just prior to the hammer dropping. Keeping you finger in the rear position on the trigger, pull the slide to the rear and let it come forward into battery. Notice the firing pin safety block. It is downward position, flush with the slide. Now release the trigger and start to pull it to the rear again, you will see the safety start to release again. Now the hammer will drop, contact the firing pin and the firing pin can move forward and strike the primer. As long as the firing pin safety is functioning correctly, the pistol could not go full auto. The exception is where the trigger bar/trigger mech. malfunctions and fails to reset the firing pin safety and lets the hammer contact the firing pin. Also, as a side point, maybe someone can clarify this. Some years ago, there was a recall on a shipment of SKS rifles and I believe it was because the firing pin was malfunctioning causing the weapon to go full auto. I am trying to find the paper work on the notice.
I edited this to say: When a weapon is designed to be full auto, The hammer (or striker) is what makes the weapon function fully automatic. When the bolt or slide has returned to battery and the trigger is still depressed, the hammer/striker will then drop. And yes, if the slide/bolt returns to battery with the hammer riding it, that is a slamfire also. DOA can not slamfire with the hammer riding the slide back to battery because of the passive firing pin safety. (keltec uses a heavy firing pin spring instead of a safety block) My example involves a malfunctioning semi auto.
 
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Blackhawk - never say never.

The way I heard the SAA full-auto account is that the expanding gases escaping through a punched primer would push the hammer back. High pressure gases can certainly do that. Think what they can do if, oh say, a 240 grain object gets in their way as they try to get out of the gun.

Do I have proof? No, but like I said, it is plausible.

On the DAO failures, you're putting way too much faith in a strong firing pin spring. Springs break. The breaking of which might be the cause of the pin being jammed forward.
 
dj1726,

Excellent post, and I agree with everything you said.

Glocks are not true DAO guns if you use the definition that calls for the gun to be fully uncocked when the trigger is fully forward and that cocking is done exclusively by the trigger. Glocks are always half cocked when a round is in the chamber. They're entirely capable of full auto.

DA/SA guns are uncocked only when the hammer is down in DA mode. Once they're in SA mode, they're entirely capable of full auto.

Full auto with Glocks or DA/SA guns requires a parts failure either from breakage, crud, wear, or maladjustment. The forces and vibration from a deliberate shot are tremendous, and a dirty gun can delay the movement of parts crucial to preventing the hammer from falling. So can congealed grease in very cold weather!

I'm not saying DAO guns like Kel-Tecs cannot go full auto, but it's far less likely than with DA/SA, SA, or Glock actions. The latter actions require post first shot movement of parts to PREVENT firing the next round while DAO actions require post shot movement of parts to CAUSE firing.

DAOs are just inherently safer and more immune to firing at all merely from racking the slide than other actions, and that was my original point.

The Kel-Tec action isn't unique from this perspective: If the firing pin is stuck extended, it will catch the rim of the next round as it's loading jamming the pistol since the round has to slide against the slide to go into battery. Other locked breech actions probably also share this attribute, but blowback pistols are probably not so endowed.
 
This is the reason that when I fire a new-to-me semi-auto (whether pistol or rifle), I load 1 round in the mag. If that's ok, then I try 2 a couple times. If that's ok, then I'll try 5.

But giving it another go with a full mag after it has already gone auto once? Shudder. That's just nuts.

M1911
 
Mal H,

Did I say "never"? I hope not, because every time I have in the past, greater powers than I have laughed and said "Oh, yeah?" :D

At 0.159 square inches, the "piston" area of the 240 grain bullet is 33 times greater than the effective piston area (gas through a 5/64" hole) of the primer at the same pressure. At a peak instantaneous pressure of 35kPSI, the applied force on the bullet is 5,567 pounds, and the effective force on the primer would be 168 pounds.

I doubt that an unsupported primer would even move when such a force is momentarily (maybe 0.001 second) applied, much less be ejected with vigor. But say it was. You'd effectively have a very short barreled gun firing a projectile of (how many grains does a primer weigh, anyway?) nn grains at a velocity of not very many fps. (Maybe we can get Jim Keenan to test this.) My guess is that it would be like shooting a hammer with an aluminum BB from a Daisy Red Ryder BB gun.

As for the "high velocity" gasses, a firing pin is quite aerodynamic from that direction, and so is the hammer it's attached to. So, forget high velocity gasses.... :D
Do I have proof? No, but like I said, it is plausible.
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It's not plausible to me. :D
On the DAO failures, you're putting way too much faith in a strong firing pin spring. Springs break. The breaking of which might be the cause of the pin being jammed forward.
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I have MUCH more faith in a strong firing pin spring in a DAO pistol preventing full auto than I do in moving interference parts preventing full auto in DA/SA or Glock pistols. Too much? No, just much more by comparison.

When compression springs in a channel break, it's just like having two springs end to end applying almost exactly the same force. The chances of a broken spring jamming a firing pin in a position opposite of where the springs' force is applied are prit near zero! :D
 
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