The true meaning of "Slam Firing" and why it is so dangerous

[Coyote Cap, SASS Life #14184]

The term "Slam Fire", (originally), had nothing to do with holding the trigger down, as is the popular belief today for the meaning of the term "Slam Firing". It has everything to do with the surprise one experiences when your Win, M-97 decided to fire "all by itself", when you slam the action closed on a live round - - - - read on as to the history of "Slam Firing" and why it is so dangerous.

The John Browning M-93 (now called a Winchester M-97) was designed to be a very safe firearm and that gun could NOT fire when slamming the action closed on a live round. But interestingly, Winchester engineers "thought" they were smarter than John Browning and stupidly made serious and deadly changes to Browning's original design of the M-93.

Winchester design changes were so serious, they were forced to recall the M-93's and changed the name of the same gun to M-97. The Browning M-93 was so safe, it had multiple automatic safeties, including a spring loaded, rebounding firing pin and a solid shell flag on the carrier to prevent an out-of-battery discharge. Both those designs were changed by Winchester (and as years went by, more changes, to compensate for stupid earlier changes) and that is when the gun became the killer of today that it is.

Let me explain !

Browning designed several automatic safeties that Winchester took out, and it took me several conversations and two trips to the IAC factory in Rizhao, China, to convince IAC execs to allow me to change the reverse engineered (from a worn-out Win M-97) when building the first Norinco (and later) IAC, M-97's back in 1998. I wanted IAC to return to the original Browning design of the M-93, to correct the problems caused by Winchester gross stupidity, because the IAC, M-97's were being built for SASS, and I wanted those guns to be ultra-safe and almost indestructible.

Back in 1892, John Browning designed the 93 to have a spring loaded "automatic" safety firing pin and no disconnecter, because if you noticed the trigger is always in the "pulled" (released) position, until the action is fully closed with the carrier up behind the bolt, a disconnecter was not necessary, as the trigger could not be pulled.

Inside an M-97, at the moment the carrier is fully up and behind the bolt, the sear cocks the trigger forward, the firing pin intercept bar (another automatic safety) is pushed up by the carrier, the hammer is fully back and the gun is now ready to fire - - - - it is a very safe design ! - - - - until Winchester decided to "Improve" on John Browning's genius and those changes became a serious killer.

Right up until the turn of the century, primers were very hard and ammunition manufacturers were advised to change from steel to brass for primer construction, but Winchester knew better and did nothing, so misfires became an issue for Winchester Engineers.

They decided the John Browning designed, light weight, spring loaded (automatic safety) firing pin was causing the misfires, so Winchester changed the firing pins to a very heavy "Free Floating" firing pin to replace the automatic safety firing pin of the M-93 and that, combined with softer primers is when the trouble really started.

Winchester wanted the hammer to hit the heavy firing pin with enough force to dent the steel primers hard enough to cause the shotgun shell in the chamber to discharge. Unfortunately, the John Browning designed mainspring was too light and the hammer could not hit the new heavier firing pin hard enough, so Winchester changed the mainspring to a thicker, stronger mainspring.

(NOTE), the very heavy mainspring is what is the major cause of wear in the (soft metal) Win 97 action.

When Winchester "Finally" listened to consumer complaints, they went to softer primers and that was when their mistakes of the past caused the M-97 to become the slam firing killers that they are today.

Let me explain the REAL REASON for the term "Slam Firing" and why the Winchester M-97 became such a killer when the Browning M-93 design was so safe.

This is as simple an explanation as I can think of, to get SASS shooters to understand why, over a span of 17 years and four trips to China, that I made all the major changes to the IAC shotguns that I did.

Get your Winchester M-97 out of the vault and open the action. Notice the firing pin can be pushed into the bolt very easily ! That firing pin is the "Killer" and I warned IAC execs and also SASS Wild Bunch members of the danger.

If you have a fired empty hull, take out the dead primer and put a live primer into the empty cartridge. Put that (primer only) cartridge into the chamber, Close the action and place the hammer on 1/2 cock "safety". Now, pick up the shotgun and drop it on the buttplate from about two feet high, (DANGER - - keep your face away from the muzzle when you drop the gun). As the gun hits bottom, the firing pin will fly upwards and more often than not, discharge the primer of that dummy round.

This process is called the "Drop Test", which is a mandatory factory "automatic safety " test.

Imagine your Dad or Granddad, out duck hunting, with a live round in the chamber and the Win. 97 on 1/2 cock safety ? Their hands may be wet from duck hunting and when crossing a fence, the gun slips from their hands and falls to the ground on the buttstock.

What do you think will happen ?

Dad or Granddad doesn't return home for supper, so the Sheriff is sent out to find him. They eventually find him with 1/2 his face blown off or a full blast of shot to his chest. He is dead ! His Win. M-97 is ON SAFETY, but the round in the chamber has fired ! It is Winchester's fault, they knew about it, but failed to correct the problem, even to the end of production and over one million built.

Imagine yourself or your wife shooting Cowboy Action Shooting and on one stage, your Win. 97 has an "AD" into the dirt and you get a stage DQ for it. You ask yourself, "did I have my finger on the trigger, when I closed the action" ???? Ask "Hipshot" about this, as he sent his Win 97 to me to correct the AD problem his Win 97 was causing him. What I did was to remove the old "free Floating" firing pin and the old heavy mainspring and replaced both with an IAC "Titanium" (safety) firing pin and rebounding spring and also a .200 mainspring from an IAC, M-93/97 - - - but I didn't tell Hipshot, the parts came from the same gun that SASS banned.

"Slam Fires" happen when you are using a Win M-97, and you slam the action closed and the heavy free floating firing pin fires the round in the chamber from the sudden and forceful slamming the action closed.

When you hold the trigger down on (ANY), M-97 and slow cycle or fast cycle the action. The gun will fire, and it doesn't make any difference if the action is cycled very quickly, or very slowly, the gun will fire, only AFTER the action is fully closed and safe.

The SASS Cowboy Action term for "Slam Firing" is not correct, but sure sounds cool !

This is your "long winded version" of Slam Firing and where the term originated.

Respectfully submitted,

"Coyote Cap"

[Painted Mohawk SASS 77785]

Thanks for the post Cap...That's exactly why a Win 97 I bought back into Australia a few years back failed the 'drop test..luckily I got it all sorted & it's now in my safe..can't use it in competition yet [ hopefully in the future we will get the green light ! ]..for now it's registered to our property for feral animal control .

[Cypress Sam, SASS #10915]

Cap,

All this is great stuff. Your info not only on the 97/93 but the 87 and Stoeger doubles as well should all be gathered together and put in a book! I'd sure buy a copy.

 

The 97 is not the only SASS gun that will do unintentional slam fires as I'm sure you know. The Uberti73 and the 1911 will both slam fire when the actions are closed too hard.

 

Let me know when you get the book done. Just don't wait too long! I'm old.

[Capt. R. Hugh Kidnme]

Cap,

All this is great stuff. Your info not only on the 97/93 but the 87 and Stoeger doubles as well should all be gathered together and put in a book! I'd sure buy a copy.

 

The 97 is not the only SASS gun that will do unintentional slam fires as I'm sure you know. The Uberti73 and the 1911 will both slam fire when the actions are closed too hard.

 

Let me know when you get the book done. Just don't wait too long! I'm old.

After reading this post and the Win '87 one, I agree with Cypress Sam. You should get this info into a book format. Your years of experience are worth the price.

[Chili Ron]

Howdy,

I got to spend a while in Caps kitchen and I wished Id had a video recorder

on when I left.

He sure has a grasp of things mechanical.

Things that look bad can be very good and the reverse.

Its very interesting how something can work most of the time but fail

in a very spectacular manner.

I once fixed a computer program which ran fine for six years then abended.

Four or five programmers worked every spare minute for almost a week finding

that flaw. No it didn't blow anyones head off, but.....

Best

CR

once I heard that Rolls wanted a real good transmission that they could just buy.

They didn't want to build one.

After testing they gave the turbo hydro gm trans the nod.

They took it apart and looked for places to improve it.

One machinist decided to smooth off a rough spot to a fine shine.

They put the trans back together and started up the Rolls.

Funny thing, it didn't move.

CR

 

and I will buy that book, two copies.

[Boggus Deal #64218]

The 97 is not the only SASS gun that will do unintentional slam fires as I'm sure you know. The Uberti73 and the 1911 will both slam fire when the actions are closed too hard.

 

 

My question is how do you close a 1911 too hard?

[Coyote Cap, SASS Life #14184]

Boggus Deal,

 

The 1911 has a disconnector, which means you have to pull the trigger with each cycling of the slide. Some early 1911's didn't have a spring in front of the firing pin and were a "Free Floating" design, but because the firing pin was so light, it didn't have the inertia to dent the primers enough to fire the round as the slide went into battery - - - - which all sounds real good - - - - except, on occasion, the 1911 would cook off a round all by itself as the slide slammed forward, and if you didn't check for high primers (prior) to loading the magazine, you were asking for a slam fire incident !

 

Been there, done that !!!!

 

The Uberti 73, is a very safe for SASS rifle - - - - except when a well meaning gunsmith, lightens the firing pin rebound spring too much and then the heavy firing pin extension can overpower the too light a rebound spring and the rifle can fire as the action is slammed shut by fast levering.

 

"Coyote Cap"

[Carolina Gunslinger]

The Uberti73 and the 1911 will both slam fire when the actions are closed too hard.

 

'73....beef up the trigger return spring and have a competent gunsmith recut the sear.

1911...check the sear angles and the tension on the sear spring tab of "leaf spring"...or what ever it really is called.

[Carolina Gunslinger]

'73....beef up the trigger return spring and have a competent gunsmith recut the sear.

1911...check the sear angles and the tension on the sear spring tab of "leaf spring"...or what ever it really is called.

Didn't think about the trigger rebound springs. That's just bananas kitchen table gunsmithing IMO.

I was thinking of common causes of hammer follow for 1911's.

[Grizzly Dave]

Cap, interesting read even though I have never had a 97.

 

So if closing the action with the trigger pulled is not technically Slam Firing, what would an accurate term for it be?

[Coyote Cap, SASS Life #14184]

Grizzly Dave,

 

I don't know pard, but would venture a guess, that a new term should be something like "Speed Firing" ?

 

Maybe others can chime in with a better suggestion what to call firing a 97 as fast as you can with the trigger pulled.

 

"Cap"

[Titus A. Gnatsass, SASS #71705]

Cap, interesting read even though I have never had a 97.

 

So if closing the action with the trigger pulled is not technically Slam Firing, what would an accurate term for it be?

 

FUN?

[Boggus Deal #64218]

Boggus Deal,

 

The 1911 has a disconnector, which means you have to pull the trigger with each cycling of the slide. Some early 1911's didn't have a spring in front of the firing pin and were a "Free Floating" design, but because the firing pin was so light, it didn't have the inertia to dent the primers enough to fire the round as the slide went into battery - - - - which all sounds real good - - - - except, on occasion, the 1911 would cook off a round all by itself as the slide slammed forward, and if you didn't check for high primers (prior) to loading the magazine, you were asking for a slam fire incident !

 

Been there, done that !!!!

 

The Uberti 73, is a very safe for SASS rifle - - - - except when a well meaning gunsmith, lightens the firing pin rebound spring too much and then the heavy firing pin extension can overpower the too light a rebound spring and the rifle can fire as the action is slammed shut by fast levering.

 

"Coyote Cap"

 

 

 

http://patentimages.storage.googleapis.com/pages/US984519-1.png

 

 

 

The original patent drawing for the 1911 had a firing pin return spring.

[Coyote Cap, SASS Life #14184]

Patent or no patent, I had a 1911 come in with no spring in the firing pin and if I remember correctly, I think it was a banned Norinco import.

 

"Cap"

[Cypress Sam, SASS #10915]

Bogus,

If you chamber a round into the 1911 with the mag out and drop the slide on the already chambered round, it will sometimes fire because of the inertia of the firing pin.

 

As you probably already know, the 1911 firing pin tip does not reach the primer when the hammer is all the way down and always fires the primer through it's inertia. Dropping the slide on a chambered round, especially if there is a heavier spring in place, is likely to cause a discharge.

[Shooting Bull]

Grizzly Dave,

 

I don't know pard, but would venture a guess, that a new term should be something like "Speed Firing" ?

 

Maybe others can chime in with a better suggestion what to call firing a 97 as fast as you can with the trigger pulled.

 

"Cap"

 

While not an exact copy, the practice of holding the trigger to the rear and moving the slide forward to fire the round in a '97 is somewhat similar to the action of firing an open bolt machine gun. In both cases it's the slide moving forward into battery that chambers and fires the round. For that reason vote we start calling it "Machine gunning" a '97.

[Ripsaw]

Grizzly Dave,

 

I don't know pard, but would venture a guess, that a new term should be something like "Speed Firing" ?

 

Maybe others can chime in with a better suggestion what to call firing a 97 as fast as you can with the trigger pulled.

 

"Cap"

 

Slip Firing? making a comparison to the same process on a revolver...

[CodyMaverick]

Slam Firing may not be the 'technically correct' term but it is pretty descriptive of the effect. Since this has been the term used for so long you may as well continue if want someone to know what you are referring to with having to use one or more complete sentences.

[Carolina Gunslinger]

How about rack and jack? Or pinnin and grinnin? Super cycling? Reciprocation firing? Slide firing?

 

There you go...

 

Slide firing the '97 refers to the action of pinning the trigger to the rear and using the forward motion of the forearm slide to close the action and fire the shotgun.

[H. K. Uriah, SASS #74619]

I have a 1911 made in 1913. Serial number is in the 54xxx range. It has a firing pin spring. How early do you have to go to find this inertia type pin?

[Boggus Deal #64218]

I have a 1911 made in 1913. Serial number is in the 54xxx range. It has a firing pin spring. How early do you have to go to find this inertia type pin?

H.K., they all had it. John M. Browning's patent drawing from Feb. 14, 1911 shows it.

[Willy B.SASS#26902]

This conversation about firing pin springs got me to wondering so I dug my Colt military model of 1905 (45 rimless smokeless) out of the safe to see if it had one, This one was built in 1911 near the end of production and yes it doe's have a firing pin spring.

 

[Boggus Deal #64218]

This conversation about firing pin springs got me to wondering so I dug my Colt military model of 1905 (45 rimless smokeless) out of the safe to see if it had one, This one was built in 1911 near the end of production and yes it doe's have a firing pin spring.

 

Now, THAT is a neat gun!!!

[Widder, SASS #59054]

It might be too late in the game to try and change terminology used to define the method (art) of pressing the trigger at the same moment the slide is closing the action causing the immediate discharge of the round in the chamber.

 

I 'slam fire'. I know 2 shooters refer to it as 'Widder gunnin'. But I don't think that would work.

 

I'll continue to call it Slam Fire, regardless.

 

 

..........Widder

[J. Frank Norfleet]

I believe the reason the 1911 always had a firing pin spring is that JMB designed it to be carried hammer down on a live round. That way the pistol could be drawn and the hammer thumbed just like a revolver. The thumb safety was an addition required by the US military before they would approve his pistol.

JFN

[Seldom Seen #16162]

Coyote Cap,

 

Now you have me worried. How safe is my Norinco 97, serial # 020xxxx, to keep loaded and to fire?

[Coyote Cap, SASS Life #14184]

Seldom Seen,

 

Your 020xxxx, is not a Norinco. It may have an early left over Norinco barrel, but I can assure you, what you have is a very safe to shoot IAC, M-97.

 

If your serial number started with a 98XXXXX, (1998), or 99XXXXX (1999), or even a 00XXXXX (2000), those guns were Norinco's and were a problem, because they were reverse engineered from a worn out Winchester M-97. A fellow with the Clinton administration, named Warren Christopher, placed an import ban on any and all Norinco products coming into the USA, because the Chinese Communist were caught selling nuclear weapons parts to Iran.

 

That is when IAC bought out the Norinco shotgun project and I was sent to China to cure the problems. Unfortunately, the Chinese have a habit of repairing defective parts and installing them in guns, instead of melting them down and starting over again. By the time the parts supply dwindled down that were used to build the 010XXXX (2001) guns, the 020XXXX (2002) guns turned out not too bad and could be made to run very strongly for a very long time.

 

Your 020XXXX doesn't have the upgraded parts that now make up the IAC, M-97w-20cb "Cowboy Comp", but it still is a good gun. You can bang it down, throw it on the ground with a live round in the chamber and your gun will not go off by itself. It is a safe gun, so don't concern yourself or lose any sleep over it.

 

"Coyote Cap"

[Nate Kiowa Jones #6765]

Back in the day, Colt actually advertised the lighting rifles as able to be slam fired. But, I don't think they called it slam firing. Anyone have that old ad?

[Garrison Joe, SASS #60708]

Back in the day, Colt actually advertised the lighting rifles as able to be slam fired. But, I don't think they called it slam firing. Anyone have that old ad?

+1 I remember lots of times reading about slam firing in ads and old gun mags. I'm pretty sure it's been called slam firing for a long time.

 

 

 

(referring to the 1911 semi-automatic pistol as a deviation from discussing Win 97 slam firing...)

The thumb safety was an addition required by the US military before they would approve his pistol.

 

No, the grip safety was added during Army trials of the 1911. Browning put the thumb safety on from the beginning of the design. In fact, the earlier Browning 1903 pistol had the same location of thumb safety. And no grip safety.

 

Good luck, GJ

[Seldom Seen #16162]

Coyote cap,

 

Your information about my gun is most interesting.

 

The gun is stamped NORINCO 97 on the left side of the barrel by the receiver. On the bottom of the receiver it is stamped MADE IN CHINA and the serial number is on a second line below it.

 

Here is where it gets interesting; the markings on the box it came in.

 

On the top of the box it is marked NORINCO 97 W.

 

On the end flap it is marked M97W 7 MADE IN CHINA. It has a sticker with a bar code the says NORINCO 97 12/20/CYL W/HAM WAL 033.

 

The serial number 0207xxx is marked twice on the end flap.

 

So I have have a early IAC?

[Yellowhouse Sam # 25171]

I got a buddy name of Slamfire. Seems like the firing pin in his roller got all gummed up and stuck in the fire position. He was a little too exuberant chambering a 44-77 round and when he slammed the breechblock closed all hell broke loose. He wasn't hurt but boy does he check the firing pins on his many rollers and observes their position before closing the block.

 

We bestowed that glorious handle on him posthaste and he's worn it not so proudly now for some 20 years!

[Garrison Joe, SASS #60708]

Coyote cap,

 

Your information about my gun is most interesting.

 

The gun is stamped NORINCO 97 on the left side of the barrel by the receiver. On the bottom of the receiver it is stamped MADE IN CHINA and the serial number is on a second line below it.

 

Here is where it gets interesting; the markings on the box it came in.

 

On the top of the box it is marked NORINCO 97 W.

 

On the end flap it is marked M97W 7 MADE IN CHINA. It has a sticker with a bar code the says NORINCO 97 12/20/CYL W/HAM WAL 033.

 

The serial number 0207xxx is marked twice on the end flap.

 

So I have have a early IAC?

 

Looks very much like you have a 2002 series Norinco. One of the very early ones, with not so good metal and tolerances. And painted "white wood" in the stocks, almost certainly. An "02" series.

 

Good luck, GJ

[J. Frank Norfleet]

 

No, the grip safety was added during Army trials of the 1911. Browning put the thumb safety on from the beginning of the design. In fact, the earlier Browning 1903 pistol had the same location of thumb safety. And no grip safety.

 

Good luck, GJ

Interesting, the patent Boggus posted above has a grip safety and no thumb safety (that I can see) and both the pistols JMB submitted to the Army had grip safeties and no thumb safety. But, as always I could be wrong.

 

http://www.gunsandammo.com/uncategorized/rarest-1911-ever-made/

 

Sorry, Coyote Cap for hijacking a very informative thread.

JFN

[PECOS PETE, SASS#16437]

What is 9980067 ?

[Garrison Joe, SASS #60708]

What is 9980067 ?

A large integer?

 

You mean, if that is on a Norinco made 97 clone, what would that serial number mean? It would mean the frame (at least) was made in 1999, by Norinco. First two digits of the Chinese 97 clones are USUALLY the year the frame was made. Often slightly set off by a space from the rest of the digits.

 

China North Industries, using Norinco name, before Norinco got in trouble with US State Dept. "In August 2003, the Bush Administration imposed sanctions on Norinco for allegedly selling missile-related goods to Iran." https://en.wikipedia.org/wiki/Norinco

 

Then Interstate Arms Corporation of Billerica, Massachusetts, became the import agency for the 97 clones coming out of the (same) Chinese factory, in 2004.

 

Good luck, GJ