Non-hijacked Steyr Safety Thread (Long)

[tetchaje]

As if Twoblink's explanations weren't enough to settle the Steyr debate, I have been in contact with Dr. Aigner (Steyr Chief Design Engineer for the M-Series pistols) several times and have asked him several questions in regards to the safety and design of the pistol.

Previous threads in regards to the safety of the Steyr M-Series pistols have most often been threads hijacked from other people's innocent questions, so I am dedicating an entire thread where MacMan10 and Jimmy Mac can duke it out with the rest of us in relative privacy, while somebody else's question can be affirmatively answered without the harrassment.

Jimmy Mac repeatedly claims that:
1) There isn't a plunger-type firing pin stop, so the pistol is dangerous.
2) The firing pin catch is subject to failure, and this would result in a discharge of the pistol.
3) The pistol can go full-auto.
4) The pistol is SA.

I will address each of these seperately (as numbered subjects below) and I will attempt to put some questions to rest for other members here (like Handy) who do not have direct experience with these pistols, but who are interested in the design and function.

----------------------------------------------------------------------------------------------------------------

1) "There isn't a firing pin stop, so the pistol is dangerous."

It is true that the Steyr pistol does not have a traditional plunger-type firing pin stop, as seen on SIGs, HKs, Glocks, et cetera. However, the Steyr does in fact have a firing pin safety. The sear (Part #10) is blocked from rearward movement by the sear lever and drop safety (Parts #32 and 11). The sear will not release the firing pin without rearward movement of the trigger (after the trigger safeties have been disengaged, of course).

The BATF classified the Steyr pistol as having a "firing pin block" which is not a direct firing pin safety, but uses the combination of the trigger and drop safeties to block the firing pin from forward movement. Basically, the firing pin will not fall forward unless the trigger is pulled.

From what I understand, the Springfield XD pistols don't have a plunger-type firing pin stop either, but rather a firing pin block similar to the Steyrs. I don't hear a zillion complaints about that pistol. Besides, the XD is classed by the BATF as a SA pistol (more on that later)...

...which leads us into the next comment...

2) The firing pin catch is subject to failure, and this would result in a discharge of the pistol.

This is where the fun really begins.

According to Dr. Aigner, the force on the firing pin during firing is 30 Newtons, but the force required to break the firing pin is 16,000 Newtons. This means that the firing pin is 533 times stronger than it ultimately needs to be. In engineering, this is referred to as a "Factor of Safety" or "FS". In enginnering speak, the firing pin has an "FS of 533."

Let's put this into perspective. Suppose Jimmy Mac and MacMan10 fly home to see their mothers for Christmas. Well the Factor of Safety on a commercial jetliner is about 1.2 for all critical components. It has to be this low in order to save weight and to make flying economical. In other words, the plane is only designed to withstand 20% more force than the maximum force that it is expected that it will experience in its lifetime.

So, with an FS of 1.2, you are 444.2 times more likely to have a catastrophic failure with a critical component of a commercial jetliner than you are with your Steyr firing pin.

"But what about fatigue and corrosion," Jimmy or Macman might say. My response to that would be to again consider the airline industry. Many planes, with a mere FS of 1.2, fly for 30+ years without any major failures. There are notable exceptions, like the Aloha airlines flight that had a fatigue failure of the fuselage, but by and large it is quite safe to fly on a jetliner that is definitely in more of a corrosive environment than a well-cared-for pistol will ever be. (If you say that "aluminum doesn't corrode" you obviously know nothing about engineering materials, and your input into this discussion would be a fallacy...)

Remember that the FS for the firing pin is 533 -- as opposed to 1.2 for commercial aircraft. Dr. Aigner told me that, "We have fired 150000 rounds with no breakage of the firing pin or sear." Not too bad of a track record if you ask me.

3) The pistol can go full-auto.

If I remember correctly, Glock had early models (before the "voluntary upgrade"... ) that had incorrectly designed slide rails and extractor and firing pin assemblies. The result? Slam-fire and Full-auto fun! Oh yeah, in 1992 the Glock failed the DEA's frisbee test, too. (http://communities.prodigy.net/sport...-gupgrade.html)

What I am getting at is that early pistols may have had some problems. Even the "perfection" of Glockdum had a "voluntary" upgrade to replace extractor and firing pin components to remove the possibility of slam-fire and full auto.

A severely out-of-spec Steyr may have done what Jimmy and Macman claim. However, let us not think for a moment that other "perfect" pistols are immune to early teething problems.

I have never heard of problems with Steyr problems after the first few thousand serial number range. Mine are in the 9XXX and 16XXX range and have been absolutely perfect.

4) The pistol is SA.

This just shows a lack of understanding of the design. The BATF classified the Springfield XD as single action because the striker is fully cocked upon the slide locking shut. However, the firing pin block and other safeties make this pistol quite safe. I wonder why Jimmy and Macman don't get all flustered about those pistols.

The Steyr is classed as DA because the sear moves rearward and continues to cock the striker when the trigger is pulled. Hence, the BATF DAO designation, and the true function of the Steyr pistol.

The striker is cocked approximately 72% of the total cocking distance when the slide is shut, and requires continued cocking with the rearward movement of the sear to complete the firing cycle.

http://petej55.home.mindspring.com/xddasa.htm

Now another tidbit of safety in regards to why the Steyr is actually MORE safe than Glocks...

Yet another conversation with Dr. Aigner revealed this bit of information...

Dear Mr. "Tetchaje",
First of all, the Steyr pistol is completly save and it is impossible to
fire when the slide is out of battery.
The Steyr pistol is not a Glock copy, it is a new design with new solutions.
The reason for an additional firing pin safety is to prevent to fire a round
when the slide and bolt are out of battery.because the cartridge case is not
supported
Most pistols need this devise because of they have a very short straight
travel of the slide connected with the barrel until the barrel is unlocked.
E.g.Glock 1.5mm, SIG 2.5mm.
The Steyr pistol has the longest straight travel (3.5mm) of all pistols on
the world market and the unlocking way is 5mm.
1. Theoretically it is not dangerous for the shooter if the bolt is
pulled back 4mm and fired a round because the barrel is still fully locked
to the slide.
2. On the other hand the force of the firing pin spring is droped down
to an amount that it has to less energy for igniting the primer when the
slide is drawn back 4mm.
3. If you pull back the slide (4mm) , the barrel is controlled by the
multifunction part and steered downwards (1.5mm) so that the primer is no
longer in line with the firing pin. For correct igniting the firing pin has
to hit exactly the center of the primer.
When I started with the design of the pistol I tested a lot of without one
firing a cartridge in the positon out of battery. So an additional firing
pin safety is unnecessary but we have integrated a manual safety and key
lock which provides an ultimate combination of applied and mechanical
safeties.
Also the ATF in Washington and the Austrian army tried to fire a cartridge
(out of battery) with no succsess.

We all know that Glocks have a nasty habit of firing out of battery when they get dirty. This has been the cause of numerous kB!s and other malfunctions with Glock pistols. Just one more reason as to why I continue to buy Steyr pistols instead of Glocks.

Let the argument begin...

[NMGlocker]

sorry...... your arguing with facts and data to back them up, that just won't do...... would you mind making something up for us?

[Jimmy Mac]

When all the BS is over it leaves one question. Will the gun fire from the so called 72% that you claim it is cocked if the striker or sear failed?

I don't know where you get 72% because in my opinion it is more like 95%.

But just for now we will say it is 72% cocked.

You now claim it is almost impossible for the tab on the striker to break. That may be 99% true.

There is one fact that is for sure. If it does break the gun WILL FIRE.

Also I have see with my own eyes A Steyr pistol go full auto and and with my own eyes I have seen one that would fire if you lifted up the slide. This can not happen with a DAO.

No matter how you word it or no matter what you or anyone else posts you will not make me belive this is good design.

[Jimmy Mac]

Now the single action XD.

It does have a true firing pin lock. If the sear or the tab on the striker should fail or even if the slide was forced off the pistol the firing pin lock WILL keep it from firing.

No matter what they call their internal safetys on the Steyr they ONLY BLOCK THE SEAR AND TRIGGER.

There is nothing to stop the so called 72% cocked striker from going forward and hitting the primer if the sear or tab failed. This is a fact no matter if you like it or understand it.

Now the only question is this likely to happen.

Not in a correctly fitted pistol using good parts but it has happened in those that were not correctly fitted.

But the thing is it could happen and cause an AD in this gun where the same thing happening in something like Glock or XD would be almost impossible.

[tetchaje]

Obviously Jimmy didn't read my post...

Let's see here...FS of 533 for the Steyr, FS of 1.2 for a commercial airliner...

...oh yes, a real big danger there.

The Steyr has a firing pin block, and the tab won't break without completely destroying the gun.

Hey, Jimmy, I understand that the HS2000/XD doesn't have this magical feature that you are talking about. Can you please post a picture of the XD parts diagram so that I can be corrected with some actually verifiable data?

Also, it has been repeatedly verified that Glocks can and have experienced out-of-battery firing, slam-firing, full-auto, and of course, the ubiquitous kB!. Please verify all of your claims, Jimmy, as this is getting tedious. Do you have one verifiable shred of evidence?

[twoblink]

I am studying to "hopefully" design my own pistols and rifles later on. I have studied a few "family" of designs; and I have to say that the Steyr bring a few old ideas onto the table, while incorporating a few new ones.

First, my biggest complaint about the Steyr with regards to safety is the description and terms used. The "sear" in the Steyr is not like a traditional sear, and so to use "sear" is really incorrect; it has multiple functions; it's wedged up REALLY high about 2.5mm into the path of the firing pin; and thus it's a firing pin safety; the style of trigger is really interesting; not unlike a Mauser; where there's a drop block.

As I had said in a private message; a few things have to happen for the Steyr's to fire.

#1) Pull the trigger; this action moves the sear platform rearward, and then drops downwards, and thus you have a completion of cocking and then a release.

#2) The sear and firing pin have 2.5mm missing total on it. This would mean a non-engagement, I am not sure if the primer will fire because the spring is not fully cocked. But if this happens, I fully believe this gun will SLAM FIRE AND GO FULL AUTO. But folks, please name me a gun, that will allow for a 2.5mm errosion on a sear or firing pin, and NOT be dangerous???

#3) The slide has a 3mm play. Again, no gun (glock or otherwise) with 3mm's of play on the slide in the VERTICAL direction, can be deemed safe. It is SOOOOO far out of design spec that it's a crapshoot at best.

#4) You drop or hit the gun SO HARD that something internally breaks. Well, if you are breaking things inside a gun, then you are on your own there. Again, Break a few parts in ANY gun's inner'ds and there's no guarantee of safety.

It's just like when people say "xxx guns suck, they go full auto on you, trust me, I have one and it did.." and forget to mention little details like "I filed down the sear with a dremel last night".

If the safety pin tab on a glock broke off, then the plunger firing pin block that Jimmy Mac and company love so much, becomes useless.

The system is safe because it's a drop-block action. The sear moves rearward to complete the cocking, and then drops off. That requires movement in two planes, rearward, and then down. There is a drop safety, which looks like a little rail, that forces the sear platform to not move vertically until it has moved horizontally. There is a trigger safety, to prevent movement of the underblock until the trigger is depressed.

Because the sear acts also as the firing pin safety, an out of battery Steyr cannot fire, because the engagement is not there, thus there is no tention on the spring. This is apparent in the safety of the design, the cocking happens ONLY in full battery; this is not by accident folks, this is by DESIGN. Hard to slam fire a Steyr, because if the situation was that the sear was worn out and thus didn't catch, it would never cock the firing pin, and thus the gun wouldn't fire. This design is called a "reset" because you have to reset the sear platform in order for the next firing. It's like those dunk tanks at the carnivals. Hit the target, guy goes in the water, but someone has to reset the platform. I think this means that this gun cannot be made to go full auto (like say a Glock 18) but I don't think full auto is all that useful in a pistol or part of the desires of the original design.

Again, like my LONG LONG LONG thread before; a good safety system requires two planary movements; and hopefully multi-axis movement as well. Even better if there are sequence requirements. Steyr satisfies this; the sear has to move rearward, THEN downwards, so you have multi-plane movement requirements in sequence. Add to it a trigger safety which requires a linear rearward movement that causes a slight movement about an axis (multi-force type, rotational vs. linear only) and you have a very well designed pistol.

Jimmy Mac only proves one thing; Pistol design isn't done by rednecks with no college education; and that not everybody can design a gun.

[MrAcheson]

Your post is wrong in a multitude of ways. Incidentally just to post my credentials, I am a mechanical engineer with both a bachelors and a masters. My masters focused on materials. I post this because it means that I do qualify as an expert when it comes to mechanical design and materials.

On to the numbers:
________________

1) The big issue with the Steyr safeties seems to be redundancy. That is to say all the safeties are tied to the sear none are tied to the firing pin. This is bad because the main problem people seem to have with steyrs is that the gun fires doubles because the sear can slip if it is sufficiently out of tolerance. This is bad because if the sear slips when your not shooting you get an AD. Ideally Steyr should work like the Glock, HK and others where there is a safety to prevent sear movement and another safety to prevent firing pin movement.

2) Notice that your comments about safety deal with the firing pin itself not the firing pin catch which was the original criticism. Also everything you said about airplanes is dead wrong.

The factor of safety of most aircraft critical components is much higher than 1.2 especially structural components. Planes are made of aluminum (and increasingly composites). Aluminum is not especially subject to corrosion (unless you stick it in something fairly nasty), but has distinct problems with metal fatigue. It does not have infinite fatigue life. Therefore aircraft must be designed to meet this by increasing the factor of safety to extend the fatigue life of the aircraft structure past its expected usage life. So for a single flight the factor of safety under normal loading is probably around 3, but over the life of the aircraft the FS might be as low as 1.2.

Incidentally Aloha airlines had problems due to improper maintenance and metal fatigue not corrosion. If the factor of safety of the craft was as low as you say it should have broken in two when the upper section of the aircraft tore away because the remaining parts of the aircraft would have probably been undergoing over twice their intended load.

As for factory tests, just because the factory has tested arms, does not mean they won't catch problems. Chances are they have tested too few guns to catch any problems more than a few standard deviations out in their manufacturing process. Let alone torture tested that many guns as you suggest. Firestone's tests of their tires didn't catch tread separation either and think of how many people that killed.

Firing pin catches and hammer safety notches can break also break. Colt SAAs have killed and wounded lots of poor fools who kept/carried them with live rounds under the hammer and unfortunately dropped their guns on the hammer. So did the even tougher early model Rugers. That is why Ruger installed the transfer bar.

3) This is a logical fallacy. Just because Glocks had a problem and fixed it does not mean that Steyrs having problems is ok. Its still bad if they don't fix it. Which they don't seem to be doing incidentally. We have had multiple people on the wire remark that they have had problems with their steyrs shooting doubles. While that may be two in a fairly large number (100? 1000?) its still pretty significant if you think that hundreds/thousands of guns may have or develop this problem.

4) Again even if the XD did have a problem, it does not absolve the Steyr of having a problem. I believe one of the issues with the XD is that it has superior safety redundancy than the Steyr but I have not looked at this closely so I may be wrong.

Question can you fire a round if the firing pin hits the primer with only 72% its usual force? Most likely you can if you have a light primer. 72% is still of the order of magnitude necessary to discharge the round, 25% (ish) on the glock is not. The glock has a third the force and a ninth the stored energy. And it had a direct firing pin block. Yes this is not technically Single Action, however it is a lot more than Double Action. Its some sort of partial cock that is much closer to SA than DA.

Also note that primers can fire if hit off center. Go to the revolver forum and suggest that this isn't the case and they will laugh at you. If primers couldn't fire if hit off center then you would never have to worry about a kB! because a revolver got out of time. The primer could never go off. This is ludicrous and the first thing someone with revolver exhibiting timing problems will likely hear is "stop shooting that gun before it kills you". Likewise using pointy bottleneck rounds in tubular rifle magazines would not be the really bad idea that it is.
________________

So basically, all safeties are tied to the sear, the sear only needs a slight amount of additional movement to fire. If the sear releases an only partially cocked firing pin it has a better than 50/50 chance of an AD. Evidence of this has been presented by individuals who's steyr pistols have routinely fired doubles due to either bad handgun tolerances or wear.

[tetchaje]

I am also a Mechanical Engineer, MrArcheson, with a Bachelor's and almost a Masters.

(My father has also reviewed the design. He has two Bachelor's (ME and CivE), one Master's, his P.E. license, and almost a Ph.D in ME.)

You of all people should recognize the FS in the firing pin.

"When in doubt make it stout of things you know about..."

Aluminum doesn't corrode, huh? Well, that's a new one. How long ago did you get your degrees? The definition of corrosion has changed substantially in the last 10 years. Aluminum is extremely corrosion-prone in oxidizing environments...it is just a different kind of corrosion than rust.

The FS on many critical components of aircraft are as low as 1.2. Why do you think that the composite tail section of the Airbus fell off in NY? It is presumed that simple vortex shedding from a previous aircraft caused the critical stress to fracture the composite structure.

Yes, more and more composites are being used in aircraft, but remember that most of the US fleet of airliners are more than 10 years old. Also, composites have other weaknesses w.r.t. off-axis loading and shear. A couple of good friends of mine are currently researching this very phenomenon here at the University for their Ph.Ds.

The Aloha airlines flight was caused by corrosion-fatigue, or the synergistic effects of both of these degrading processes. Fatigue crack expose new surface area which immediately oxidizes into the very hard Al2O3 (sapphire) which acts as a cantilever for further crack propagation, and further corrosion.

My point is that other things that many people take for granted as being "safe" are in fact a lot less safe than they would expect.

[Jimmy Mac]

First the sear is not the problem here. It does not matter if the sear is make of a 30 pound block of solid steel welded to the side of a Sherman tank that is set into 100 tons of concrete.

The problem is the firing pin or striker has NOTHING to stop its forward movement if the slide is moved upward or the tab on the firing pin that the sear holds should break.

The only question is will the gun fire from its so called 72% cocked position if this happened?

What our highy educated twoblink is not capable of understanding is the Glock HAS A FIRING PIN LOCK. The sear tab could break on a Glock and the firing pin is still locked by the plunger. And also the Glock striker is not cocked enough to make this a problem to start with.

Anyone can tell from your posts you know nothing about a Glock so perhaps you should stick with the Styer that you know even less about.

[Jimmy Mac]

Aircraft and their stress from flight have nothing to do with this.

You can aruge stress and lift and whatever all day and it has nothing to do with firing pin locks and single action pistols.

[tetchaje]

Jimmy is speaking blindly here.

I'm talking about factors of safety in design.

Blindly fly, my friend, blindly fly...

[Handy]

The last time we did this a poster did try my experiment of detonating a primed case with a Steyr slide and the striker held at the lauded 72% position. The case did fire. So we know that it will if the sear breaks.

The question comes down to "could the sear break?" Unfortunately for me, I've never been able to find an M to take apart, unable to locate a parts diagram online or convince any of the Steyr owners to post a picture of the parts involved.

MrAcheson is echoing what I've questioned in the past; is a striker design without redundancy safe? As far as engineering smarts go, I hope Tetchaje is wrong. I once flew a Navy trainer past 120% of its G limit. The wings did not break off.

Speaking of parts that break, how strong are firing pins compared to the load they take? They seem to break sometimes. Throwing strength stats around in a vacuum doesn't help anything. How strong is a 1911 sear? How about the striker hook on the Glock. Do you have these numbers to compare?

[tetchaje]

Here is a parts diagram for you Handy.

Also, many planes do have a FS greater than 1.2 on many components. Wings are a good example of this as it is expected that these are going to have greater stresses and fatigue than other components like...say...landing gear.

The end result is that you can't break off the firing pin tab without destroying the entire gun.

[Jimmy Mac]

The tab on the firing pin is not so likely to break. It is very strong and oversize. Does this mean it WILL NEVER BREAK?

But when it is all said and done you ARE betting your life and everyone elses on this one part.

Other modern designs have a back up to prevent an AD if this should happen.

Even the 1911 has this feature. The manaul safety blocks the fall of the hammer.

[rcbs]

It does have a true firing pin lock. If the sear or the tab on the striker should fail or even if the slide was forced off the pistol the firing pin lock WILL keep it from firing

Not necessarily true. The first big recall on Glocks resulted from the fact that if the Glock was dropped or thrown hard enough the slide came off the frame and the pistol would fire despite its passive firing pin safety. The new safety system is supposed to correct this problem when the slide comes off of the frame. Of course the real fix would have been to redesign the frame so that the slide could not come off to begin with.

In other words if the passive firing pin safety is not of a correct design weapons of this design can still fire. Don't ask me how, I am not an engineer but in tests that were conducted this did happen.

Striker fired weapons have been around for a long time and in the traditional steel frame to steel slide models the only safety built into a lot of them was a deep contact between the stricker and the sear. Many had only a safety that blocked the trigger from rearward movement. The only trouble with these systems came when people started reducing sear to stricker contact to improve the trigger pulls. In other words deviating from the engineers original design. After many thousands of these pistols were built history has shown that they were safe to carry and use as long as the gun was not tampered with or the internal parts worn down to the point where the stricker could slip the sear.

I do not own a Styer but remember reading that there is a steel frame rail inserted into the plastic frame. Unlike the Glock that has a slide that rides on four small carbide buttons the Styer has a steel slide that is fully supported by steel frame rails. I do not understand how you could raise up a slide that is fully supported by steel frame rails unless the gun was so out of speck that the slide literally rattled and bounced around on the frame rails.

[Jimmy Mac]

rcbs

I dont know where you got this info but it is new to me.

Lets just say it is true. The Glock is basically a DAO with a striker that is about 25% cocked and it HAS a real firing pin lock.

You claim they have fired from a hard enough shock.

The Steyr they claim is 72% cocked without ANY type of lock.

Now which one you want to throw against a wall and expect it not to fire.

Also aside from the XD about the only other striker fired SINGLE ACTION pistols are the HighPoint, Davis,Jennings and Bryco junk.

They have NEVER been safe.

[Handy]

With the frame rails, does anyone know if the angled rails create any additional slack.

Tetchaje, could I trouble you for the part labels? I see what looks like a big traditional striker, but don't see the sear/block thingy.

So your wings example would be that of a CRITICAL part which would have a much greater FS?

[Jimmy Mac]

ALL the internal safetys are in the frame.

The striker is free to move forward under spring pressure if something in the frame failed or if the sear hook or tab on the striker failed or if somehow the slide moved up enough for the sear to release the striker.

What they call a firing pin lock is the part in the frame that blocks the safety that blocks the sear.

No matter what they call it is is still in the frame and has no effect on the striker if the above thing happened.

[lockandrock]

I can't believe we have so many steyr safety debates


All I haveto say is buy what you like and feel safe with. Until my m40 starts going full-auto, breaking a sear , or self-destructing, I feel it is safe and has been safe in the past and will continual to be safe in the future.

[Jimmy Mac]

The problem is you may have a perfectly safe pistol for years and then suddenly without you knowing it have a dangerous one.

You will not know it untill it is too late.

I really do not see how any possible advantage the Steyr may have over other designs makes it worth the risk of carring a pistol that may have an AD.

The possibility of an AD in a Steyr is much more possible than in most other modern designs and anyone that understands gun design can clearly understand this.

The Steyr is a great gun for games. It would be a good IDPA or pin shooting gun.

They should not be trusted as an everyday carry gun.

[tetchaje]

I'm sorry that I have been out of the loop for so long with this discussion. I am in the middle of finals, so time is kind of tight.

Also, I feel that I need to amend my statements to MrAcheson. I thought about my post last night and I feel that it comes across in a rude manner, which was not my intention (I was tired and writing quickly). I do not doubt for a second MrAcheson's expertise in materials, but their have been many changes in technology and in understanding of failure modes in the past 5-10 years. He is perfectly justified in asking about which components have a FS of 1.2 in an airplane. One of my advisors is an expert in this field and I will ask him today exactly which components have which factors of safety.

Handy,
Like I said above, I will do a little research today to find out which components in an airplane have which factors of safety. I can say that even structural components on the wings will most likely not be greater than FS 3 or 4. Weight is the ultimate premium when flying, and FS is often lowered to minimum acceptable levels to maximize the cargo capacity of the aircraft. Otherwise, you'd have the Spruce Goose...

I recognize that this discussion is about the firing mechanism of the Steyr design and not aircraft, but I do admit that I need to qualify my statements about the FS of aircraft design. I'll return and report on that a little later.

Jimmy Mac,
I did mention that the Glock -- even with the plunger-type firing pin safety -- failed the frisbee test in earlier designs (refer to link above for references). As a result, Glock changed the design of their firearm to make sure the gun wouldn't discharge when the slide came off of the frame.

My point is that the Glock DID have the plunger-type firing pin safety, and it still failed. Subsequent "voluntary upgrades" (again ) admittedly fixed the problem, though. No system is infallable -- even the mighty Glock.

In the case of the Steyr, the firing pin block prevents discharge of the gun if the trigger has not been pulled, and the steel frame, with integral steel rails, mated to the steel slide prevents the slide from coming off which perhaps would have resulted in a discharge. This is a moot point, though, since, unlike the Glock, the slide won't come off of the frame without destroying the whole gun because the rails aren't just metal inserts into the plastic.

Steyr engineers recognized that the firing pin catch was a critical component in the safety system, so they beefed-up the hell out of it. An FS of 533 is unheard of in engineering design (usually because of weight reasons -- with an FS of 2.5-10 being much more common). They are making dang sure that the thing won't discharge. The added stiffness of the firing pin due to the firing pin spring assembly riding inside of the firing pin itself is just a stroke of genius.

Again my apologies to MrAcheson.

[MACMAN10]

Why did my M9 shoot MORE than one burst?
When Willi at GSI fixed it, all he did was polish the striker channel, and replace the trigger.
IF the gun had said firing pin saftey, it wouldn't have happened in the first place. A gritty striker should not cause a gun to go full-auto. :barf:

[tetchaje]

Macman,
Why did the Glock have slam fire problems and full-auto problems with the plunger-type firing pin safety in the earlier design?

May I ask what serial number range your Steyr was?

[MACMAN10]

Don't ask me, you're the "expert"
3593*

[tetchaje]

Don't ask me, you're the "expert"

Ouch, Macman, that hurt my feelings...

Now back to the function of the Steyr. Serial #3953, huh? That is still pretty early on in the game, but it isn't like it is the first batch off of the assembly lines. Definitely before the trigger upgrade, but that shouldn't have had anything to do with the burst you experienced.

Were you shooting Blazer ammo when it happened? I've read of several instances where Blazer casings shaved somewhat into the firing pin recess and caused a forward-stuck pin. This would result in slam fire each time the slide closed. I'll have to hunt around for some references to where this happened in other guns, as well, as I cannot think of which ones they were off the top of my head.

A forward stuck pin would result in a slam fire on any gun -- including those with plunger-type pin safeties because the plunger safety requires the pin to return to its original state for it to work. It is entirely conceivable that any gun would slam fire if this happened. Not having had a chance to look at your gun, and not knowing all of the information, I can't say either way, of course.