striker fired??


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BruM
February 23, 2010, 10:03 AM
Help me understand all this striker stuff. Is the striker what I always called the firing pin??
I see a lot of references to striker fired vs. hammer fired but donít understand why it is important. Searching didnít produce much specific information on the differences, or why one is preferred over the other.
Arenít all semi autos striker fired while all revolvers are hammer fired. My 1911 has a hammer but that hitís a firing pin not the primer, while some semi autos dont have hammers at least externally. What does it all mean??

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PT1911
February 23, 2010, 10:14 AM
No, all semi autos are not striker fired, but all revolvers are hammer fired...

A lot of people like the idea of an external hammer on an auto (1911, barreta/taurus 92 series, cz 75s...etc..) over striker fired for a variety of reasons... Easy to tell when the thing is ready to go, the option of decocking (safer on some than others,) and some would say more dependable given the more open and larger system.

Others like striker fired as it doesnt look as "threatening" as a cocked hammer and newer technology has allowed the dependability of an external hammer while eliminating the potential hazards of a hammer...

BASICALLY!!!

Sam1911
February 23, 2010, 10:31 AM
Aren’t all semi autos striker fired while all revolvers are hammer fired. My 1911 has a hammer but that hit’s a firing pin not the primer, while some semi autos dont have hammers at least externally. What does it all mean??

Think of the "striker" as a spring-loaded firing pin. Pulling the trigger releases the pin to fly forward and impact the primer. Glocks, xDs, S&W M&Ps and several others work this way. They don't have a hammer, period -- internal or external.

Your 1911, a Beretta M9/92F, a SIG, and lots of other autos have a hammer that falls when you pull the trigger, impacting the firing pin which propels it forward to strike the primer. Until the hammer falls the firing pin merely rests in its channel (or, usually, is held rearward by a light spring to keep it off the primer until the hammer comes down).

I've never heard of a revolver that didn't have a hammer of some kind. Some are shrouded or fully internal to keep them from snagging when drawn, but they are there. Older revolvers generally had a firing pin mounted right on the front of the hammer. When the hammer fell, the firing pin would pass all the way through the recoil shield and hit the primer. Newer revolvers, again generally, have a firing pin that is mounted in the recoil shield and floats, very similarly to the way the FP in your 1911 does. When the hammer falls it hits the firing pin which then flys forward to hit the primer.

To recap: In "striker fired" autos, the striker is merely a spring loaded firing pin assembly that is held rearward by the sear, against the pressure of the mainspring. When the trigger is pulled, the firing pin/striker is released to hit the primer.

Clear now?

-Sam

Walkalong
February 23, 2010, 10:55 AM
It's sort of like a firing pin with a big inline chunk on the back end to give it weight and have something to machine a surface on to catch on the sear. The sear releases it and it flies forward under spring pressure to hit the primer.

Echo9
February 23, 2010, 12:00 PM
This will help you visualize it.

1911 (hammer fired)

http://www.m1911.org/STI1911animation.htm

Glock (striker fired)

http://www.thefirearmblog.com/blog/2007/09/04/the-anatomy-of-an-glock/

9mmepiphany
February 23, 2010, 12:20 PM
another difference is that most striker fired pistols do not have a 2nd strike capability...you can't pull the trigger again if the 1st round did not go off

PT1911
February 23, 2010, 12:44 PM
another difference is that most striker fired pistols do not have a 2nd strike capability...you can't pull the trigger again if the 1st round did not go off

with the exception of several taurus offerings, and the smith and wesson 99....

w_houle
February 23, 2010, 01:07 PM
This will help you visualize it.
Another thing that might help is most (all the ones I know of) bolt action rifles are striker fired.

another difference is that most striker fired pistols do not have a 2nd strike capability...you can't pull the trigger again if the 1st round did not go off
Buy better ammunition?

Sam1911
February 23, 2010, 01:27 PM
another difference is that most striker fired pistols do not have a 2nd strike capability...you can't pull the trigger again if the 1st round did not go off

with the exception of several taurus offerings, and the smith and wesson 99....

And, ironically, something like "most" hammer-fired pistols actually DON'T. (Can't think of any single-action ones that do, anyway.)

So I don't think that would be a very useful distinction between hammer and striker-fired.

(Of course, it's also a feature of infinitesimally little benefit, but that's a topic for another thread... ;) )

-Sam

jackstinson
February 23, 2010, 01:29 PM
another difference is that most striker fired pistols do not have a 2nd strike capability.
Neither do a whole lot of hammer-fired pistols. Single-actions like the 1911 and Beretta 950B are well-known examples. Some DAO hammer-fired pistols do not as well; Keltec P32, P3AT, Ruger LCP for examples.
"2nd strike capability" is a trigger mechanism function: SA, SA/DA, or DAO.

gwnorth
February 23, 2010, 01:44 PM
Neither do a whole lot of hammer-fired pistols. Single-actions like the 1911 and Beretta 950B are well-known examples. Some DAO hammer-fired pistols do not as well; Keltec P32, P3AT, Ruger LCP for examples.
"2nd strike capability" is a trigger mechanism function: SA, SA/DA, or DAO.

Nothing stopping you from thumbing the hammer back on a 1911 or 92 and re-firing as many times as you want without ever moving the slide. Or am I misunderstanding your use of them as "examples"? They most certainly are examples of double-strike capable firearms.

Sam1911
February 23, 2010, 01:52 PM
Nothing stopping you from thumbing the hammer back on a 1911 or 92 and re-firing as many times as you want without ever moving the slide. Or am I misunderstanding your use of them as "examples"? They most certainly are examples of double-strike capable firearms.

Not by any common definition. To be "double-strike capable" the hammer or striker would have to be able to be cycled repeatedly by simply pulling the trigger over and over.

The concept is that under emergency situations you'd be able to pull the trigger repeatedly until the round fired -- similar to a double-action revolver. Unlike a DA revolver, though, a "second-strike" auto doesn't bring a fresh round under the hammer so the value of this exercise is questionable.

The more trusted response to a dead primer/dud round is the "tap-rack" operation to clear that round, recock the gun, and prepare to fire again -- somewhat similar to your suggestion but with the added benefit of bringing a new round into the chamber.

By the definition you've used, ANY gun, including a muzzle-loader, would be double-strike capable as you could always re-cock the gun by hand.

-Sam

Nick5182
February 23, 2010, 01:56 PM
Simply put, a striker-fired weapon has the firing pin pulled forward by spring tension being released, and a hammer fired weapon has the firing pin pushed forward by inertia from the hammer strike.

gwnorth
February 23, 2010, 02:00 PM
By the definition you've used, ANY gun, including a muzzle-loader, would be double-strike capable as you could always re-cock the gun by hand.

-Sam

Not entirely true. I see a big difference in thumbing a hammer back, without cycling the whole action, versus say a Glock, where the only way to recock the action is to cycle the slide. There is a difference between a weapon that can be re-cocked without chambering a fresh round versus one that requires you to eject the unfired cartridge and chamber a fresh one just to recock the firing mechanism.

chris in va
February 23, 2010, 02:05 PM
My Kahr allows a re-cock without chambering a fresh round. Pull the slide back about halfway.

mgmorden
February 23, 2010, 02:26 PM
It's not hard to understand once you get the hang of it :).

On a traditional hammer-fired semi-auto, there is a spring in front of the firing pin pushing it to the back of the slit. Keeping it pushed back ensures that when it's in it's rested state, it's not sitting on the primer.

The hammer is used to hit the pin with enough force to throw it forward (compressing the return spring) so that the pin impacts the primer and detonates it.

The hammer itself - when cocked, is held back by a sear. When you press the trigger the sear is moved off the hammer and it flies foward.

Now, hammer fired designs come in 3 main flavors:

Single-action - the hammer has to be cocked prior to firing the gun. When the first round goes off, it cycles the action, loads the new round, and leaves the hammer cocked again for subsequent shots.\

Double-action - the hammer can be cocked as with a single action, but you also can fire starting with the hammer down. This will be a longer heavier trigger pull itself will pull back the hammer as well, and when the trigger comes all the way rearward the hammer is released and fires. When the gun cycles though, it leaves the action pre-cocked just like a single action. Subsequent shots are like a single-action and have the lighter trigger pull.

Double-action only (DAO) - With this type of hammer fired gun, you cannot pre-cock the hammer (there usually isn't even a grip on it to do so). You have to perform the long heavy double-action trigger pull like described above, but after that round fires, the hammer comes back to it's original rest state. The result is that you have to perform the long heavy DA trigger pull for every shot.

Striker fired guns are a bit different. Instead of a spring pushing the firing pin back, it naturally pushes the pin forward instead. HOWEVER, when the slide is racked, the sear actually engages the firing pin (called the striker in such designs) and the sear holds the pin off of the chambered round. When you pull the trigger, the sear is released and the firing pin slams forward under it's own spring pressure to detonate the round.

Basically anyways - depending on the design the pin may need to be pulled back by the trigger pull (similar to a double action hammer) some distance before it is dropped. Glock "half cocks" their striker for example - meaning it sill has to be pulled back about half-way before it drops. The Springfield XD fully-cocks their striker on the other hand - meaning that it merely drops. Other designs may only leave the striker cocked enough to keep it off the primer (the S&W Sigma does this IIRC).

When you hear "double strike capability", it basically means you can pull the trigger again on a round you snapped on and it'll snap again. All DA and DAO hammer guns will do this since they fire from a rested state anyways. SA guns won't. MOST striker fired guns won't, because they require the slide to leave them in a partially cocked position. If the striker fully falls most require the slide to rack to be ready again. There are some exceptions though (the Taurus 24/7 G2 is a striker fired gun with double strike for example).

There are also a few odd mixes. The Ruger .22 handguns for example. They utilize a bolt with an internal hidden hammer. Technically it's like a single action, but since the hammer is hidden, the gun is always pre-cocked after racking the bolt. If you snap on a round, you have to cycle the bolt again as there's no way to manually recock the hammer.

All just different ways to do the same thing. Personally though, as someone who owns a gun with almost all the designs described above (except for DAO hammer), I am a big fan of the regular DA hammer guns. They have that safe, long, heavy trigger pull for your first shot if you want it, and you still get easy, light followup trigger pulls at the target range. To me SA is outdated, and DAO and striker guns are moreso for guns that you don't intend on firing often (because their systems are moreso geared towards safety, not comfort or accuracy).

BruM
February 23, 2010, 02:46 PM
wow some amazingly well written and detailed answers thank you all. I'll need to study them in depth.

Sam1911
February 23, 2010, 03:17 PM
Not entirely true. I see a big difference in thumbing a hammer back, without cycling the whole action, versus say a Glock, where the only way to recock the action is to cycle the slide. There is a difference between a weapon that can be re-cocked without chambering a fresh round versus one that requires you to eject the unfired cartridge and chamber a fresh one just to recock the firing mechanism.

I understand fully what you are suggesting, but I believe you've misunderstood the perceived value of the "second-strike" concept.

mgmorden got it right:

When you hear "double strike capability", it basically means you can pull the trigger again on a round you snapped on and it'll snap again.

If you have time to thumb back a hammer, for a second shot at a primer that didn't go off the first time -- and probably won't go off the second time, either -- you have plenty of time to rack the slide and get a fresh round chambered, which is much better in every way.

The proponats of "second-strike" guns (and I am not one, personally) say that they value the ability to quickly pull the trigger once or twice more in the hopes of lighting off the dud round. It can be done quickly and instinctively (if you haven't developed better skills).

It is an emergency, last-ditch, do-or-die technique. (And not a very good one.) Thumbing the hammer back will let you take another shot at a bad primer, but only as a range plinking technique, not an emergency failure correction procedure.

-Sam

Hk Dan
February 23, 2010, 03:30 PM
I love your posts, Sam. You're tactful, well-informed, and we generally think alike...<g>

Ammo is cheap, beathing is expensive. Rack the slide.

Dan

Sam1911
February 23, 2010, 03:30 PM
Now, hammer fired designs come in 3 main flavors:

Single-action - the hammer has to be cocked prior to firing the gun. When the first round goes off, it cycles the action, loads the new round, and leaves the hammer cocked again for subsequent shots.
To be more clear, the hammer is cocked by the action of cycling the slide to chamber a round, making the gun ready to fire. If the gun is to be carried ready for use, the safety is then engaged before holstering. "Cocked and locked."

Double-action - the hammer can be cocked as with a single action, but you also can fire starting with the hammer down. This will be a longer heavier trigger pull itself will pull back the hammer as well, and when the trigger comes all the way rearward the hammer is released and fires. When the gun cycles though, it leaves the action pre-cocked just like a single action. Subsequent shots are like a single-action and have the lighter trigger pull.
Actually, this is called Doulbe-Action/Single-Action or "DA/SA," because the gun transitions from a double-action (lifting and dropping the hammer) for the first shot to a single action (simply dropping the hammer) for all subsequent shots. Usually these guns feature a "decocking" lever which lowers the hammer back down to the rest position if you decide to stop firing. Works similarly to a SA's safety, except you don't have to disengage it before firing again. For a while this was the most popular "modern" operating system as the operator didn't have a safety to disengage before firing. Baretta M9s, Sigs, older S&W autos, Ruger autos and a bunch of other guns operate like this. (Oh, yeah...HK's. Right Dan? :))

Basically anyways - depending on the design the pin may need to be pulled back by the trigger pull (similar to a double action hammer) some distance before it is dropped. Glock "half cocks" their striker for example - meaning it sill has to be pulled back about half-way before it drops. The Springfield XD fully-cocks their striker on the other hand - meaning that it merely drops. Other designs may only leave the striker cocked enough to keep it off the primer (the S&W Sigma does this IIRC). He heh... this is a matter of MUCH debate. The Glock, S&W M&P, and Springfield xD are VERY similar in how they operate. The distinction between which pre-cocks and which doesn't is mighty slim. Functionally, and to the user, they operate identically.

I am a big fan of the regular DA hammer guns. They have that safe, long, heavy trigger pull for your first shot if you want it, and you still get easy, light followup trigger pulls at the target range. To me SA is outdated, and DAO and striker guns are moreso for guns that you don't intend on firing often (because their systems are moreso geared towards safety, not comfort or accuracy).Technically, you are a fan of DA/SA guns. A lot of folks used to be, but the popularity is fading.

As much as I like true Single-action designs like the 1911, Browning High-Power, or CZ series, the striker-fired guns have really come of age. The benefit of having a consistant trigger pull from first shot to last is quite large. Most shooters find it easier to transition between SA guns and striker-fired guns because in both cases the gun behaves the same way for every shot. Having the first shot require a long, heavy pull and the second one break after only a short, light take-up can take a lot of getting used to, and a lot of practice to master.

-Sam

mgmorden
February 23, 2010, 07:57 PM
Technically, you are a fan of DA/SA guns. A lot of folks used to be, but the popularity is fading.


Actually, it's just DA ;). It's a bit of a pet peeve of mine, even though DA/SA has become an accepted way to state it.

A single action gun was originally referred to as such because there was a single way of firing it: from a hammer cocked position.

A double action gun was referred to as such because there were two (double) methods: from a hammer cocked position or a hammer down.

From that perspective, anything that supports both is properly termed a "double action" pistol. Saying DA/SA is a bit redundant as the DA part already states the way it works ;).

Saying DA/SA became more common when the concept of DAO came about. DAO itself was a bit of an oddball acronym, given that since a DAO only fires one way, it's really a "single action" pistol by definition, but by the time the concept had come about a lot of people associated the SA with manual cocking and DA (incorrectly) only with the trigger cocking the hammer, so they made the weird acronym DAO and people started using DA/SA :).

Sam1911
February 23, 2010, 08:12 PM
A single action gun was originally referred to as such because there was a single way of firing it: from a hammer cocked position.

A double action gun was referred to as such because there were two (double) methods: from a hammer cocked position or a hammer down.

I've never heard that before. Ever.

I was always informed that a double action trigger was so referred to because operating the trigger performed two actions -- lifting the hammer and dropping it.

In fact, from an on-line dictionary site: (¶dəb∑əl ′ak∑shən)
(ordnance) Method of fire in a revolver and in old-style rifles and shotguns in which a single pull of the trigger both cocks and fires the weapon.

And from the ubiquitous wiki:
Double-action (DA)

Invented by Robert Adams, a double-action trigger performs two functions when pulling the trigger, first cocking the hammer or striker then releasing it to discharge the firearm. When this term is applied to revolvers, the trigger also rotates the cylinder. Though this is technically a third action, it is correct to refer to the mechanism as double-action. Most pistols and revolvers with a double-action trigger mechanism retain the single action functionality.


Double-action/Single-action (DA/SA)

A double-action/single-action firearm combines the features of both mechanisms. Often called traditional double action, these terms apply almost exclusively to semi-automatic handguns. The function of this trigger mechanism is identical to a DA revolver. However, the firing mechanism automatically cocks the hammer or striker after the gun is fired. This mechanism will cock and release the hammer when the hammer is in the down position but on each subsequent shot, the trigger will function as a single action. The Mateba Autorevolver is a hybrid revolver that functions on a DA/SA system. However, it is different in function than either a conventional revolver or semi-automatic pistol. The Beretta 92 is a good example of a DA/SA semi-automatic pistol. On many DA/SA pistols (including the Beretta) there is the option to cock the hammer before the first shot is fired. This removes the heavy pull of the double-action. Also, there is often a de-cocker to return the pistol to double-action.

And, for a more gun-knowlegible source, Midwayusa.com's "Gun Tech" glossary lists this:
Definition for "double action" : (DA) A firearm action where a single trigger pull both cocks and drops the hammer. See also: double action only, double action/single action

So, I think you may have fallen prey to some colloquial knowledge in your travels.

And, clearly, when understood from the correct historical definition, a "Double-Action-Only" design is quite distinct from a Single Action mechanism. It must fire by one motion that both cocks and drops the hammer...the "double" action.

Funny thing about pet peeves, sometimes...

Don't stress it. I used to have a pet peeve about folks who didn't believe that John Browning designed the 1911 to be carried Cocked & Locked. Turns out...he didn't! :o So, I always check my pet peeves thoroughly. Folks that don't are a big pet peeve of mine! :D

-Sam

Sam1911
February 23, 2010, 08:25 PM
Oh...more irony. The revolver that Robert Adams invented was actually what we would now think of as a double-action-only! You COULDN'T cock the hammer manually. It wasn't until Frederick Beaumont improved the design that the gun could be cocked manually.

So...can we agree that the question is settled?

-Sam

mgmorden
February 23, 2010, 10:07 PM
Oh...more irony. The revolver that Robert Adams invented was actually what we would now think of as a double-action-only! You COULDN'T cock the hammer manually. It wasn't until Frederick Beaumont improved the design that the gun could be cocked manually.

So...can we agree that the question is settled?

-Sam

I'll concede :). It's not the way I heard it, but apparently my original sources were misinformed :).

Sam1911
February 24, 2010, 08:01 AM
:) I learn something new every day. Good to know I'm not the only one! :D

-Sam

Walkalong
February 24, 2010, 08:18 AM
A double action gun was referred to as such because there were two (double) methods: from a hammer cocked position or a hammer down.

I've never heard that before. Ever.In his defense, I remember being told that when I was a young man, but heck, those same folks called mags clips too. :D

What did I know? :o

Zerodefect
February 24, 2010, 08:19 AM
Cliff notes version:

Hammer fired= hammer pounds on the fireing pin slamming it into the primer.
Striker fired= spring on fireing pin "sling shots" the fireing pin into the primer.

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