MarkDozier
US Veteran
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You must immediately send that revolver to me. i am the only one here professional enough to proper operate that 686.
Hammer-mounted firing pin - better or worse?
- Thread starter aimedfire
- Start date
DonD
Member
As to why S&W went to the frame mounted firing pin, here is the answer from a S&W engineer I know. He was one of the leads on the Model 500 program and since then has become the lead in another area.
"The change to the frame mounted firing pin happened in the mid-90's prior to some states coming up with their "safe" handgun criteria. The design change was for ease of manufacturing. The hammer nose firing pin requires a complex slot in the frame that was "chopped". This was done on a manual machine dedicated to that operation. The frame mounted firing pin uses only concentric drilled holes and can all be done on a CNC machine."
Don
"The change to the frame mounted firing pin happened in the mid-90's prior to some states coming up with their "safe" handgun criteria. The design change was for ease of manufacturing. The hammer nose firing pin requires a complex slot in the frame that was "chopped". This was done on a manual machine dedicated to that operation. The frame mounted firing pin uses only concentric drilled holes and can all be done on a CNC machine."
Don
I prefer a hammer mounted pin. Probably because I grew up with them. And it is the original design for a center fire hand ejector.
Delos
Member
Old hammers that drop attached loose firing pins with an arc movement
The typical single shot shotgun firing pin is full length. When you push it down with hammer before rebound, or with a stick (with breach open) what you see is what you have. (You cannot push it further into the frame with a toothpick and see it come out further at the breach end) So the question is why a "floating" or "inertia" firing pin that either does not stick out when hammer down flush before rebounding (1911 45), or sticks out only slightly (new S&W revolvers). Sure they are used in numerous semi autos. Not just the 1911 45 auto. One article even claims the AK47 uses an inertia firing pin (that travels forward after being hit by the hammer and impacts the primer with its own weight).
So, whereas I completely believe the machining process is easier with a firing pin that does not travel at an arc. A frame mounted regular pin similar to single shot shotgun would seem logical to me, at first glance.
Either way the damage to firing pin holes seen in old often dry fired revolvers, with hammer falling at an arc, now ends.
No longer will the ridge from outward peening of the firing pin hole penetrate into a just fired shells primer, preventing cylinder rotation for next shot. Or even cause enough binding to make first shot hard or impossible. (Anyone who does thousands and thousands of dry-fire snaps in older revolvers should run his finger tip over the firing pin hole before reloading and putting it away after each session).
(What does just 15 snaps a day or 100 a week for 52 weeks add up to? There are target shooters and combat shooters who do this, most love the 1911 45 auto with its level, inertia firing pin perhaps).
So, most people do not extensively dry fire revolvers. Safety wise we can either assume the people who buy police and military handguns are educated idiots easily duped or we look harder. About 40 years ago I read that S&W lost a navy contract in (1905?) when a revolver was dropped on a ship and a sailor shot in leg. I have not looked inside old guns but the article indicated (if memory serves) that the "rebound slide" that cams the hammer back and lifts hammer block in place dates to that time (or maybe just the hammer block?).
Note number six in below diagram. And note the pin number 31 that moves the hammer block back in position, number 48. (If I remember that date correctly the last time a S&W revolver was dropped and fired was well over 100 years ago)
Smith and Wesson Model 29 Parts Diagram - Smith & Wesson Model 29 Exploded View - Shooting Photo Galleries
When you empty and dry fire the newer floating firing pin revolvers, and an old hammer attached model, side by side not much is obvious at first. Then you put a pencil down the barrel eraser first, after cocking (again be sure it is empty) and see how far the pencil travels upward. Much further with old models. Not much with the newer models. So what is the good news?
So lets talk examining the primer after shooting.
I assume the good news is that the idiots that overcharge hand loads (instead of buying a bigger gun) have less to work with as the shell rebounds against the firing pin and weight of hammer in the old, verses the shell (again pushed forward by impact of pin) slamming back against only the light firing pin of the new. The primer will look more normal now and far less likely to rupture. Rebounding shell against the weight of the hammer is no longer an issue. Thin cheap primer material from foreign sources less scary.
And if it does rupture it is extremely unlikely any gasses will make it in the small firing pin hole around the small part, or around the fatter part of the firing pin, back around where firing pin gets small again, and out around the fatter hammer surface, toward the shooters face. (Also, the firing pin being pushed back by gasses no doubt seals the back shoulder)
(No I am not an engineer. I have occasionally examined old guns. The worst firing pin hole damage was on an aluminum frame chiefs special that was being sold used in 1970 before the steel bushings were being put around the hole. Another was a stainless steel .357 that was elongated downward - I assume do to the spring under the firing pin pushing up on the back pointing front of firing pin slightly downward, or at bottom of its normal wobble).
I am not a gunsmith and I hope gunsmiths here, that have seen many more old guns than I, will give a more complete description.
Years ago, I have never seen a problem with a new or well maintained S&W revolver that had fired American made cartridges or careful reloads. So I prefer the old models in new condition.
Next best, for me, would be the old full length, frame mounted firing pin used in single shot shotguns or single shot pistols. Perhaps if I was still shooting .357 I would like the idea of the fired shell now rebounding against just the weight of the firing pin?
I am in favor of most new machining steps that keep costs down. And Alloys & Polimers that keep weight down. All my guns have or have had something trivial that I do not like. Usually the hand grips. I guess I am in favor of new firing pins that might make new hand loaders or cheap cartridges or primers safer?
Definitely safer to the reloaded who accidentally double charges a shell and blows the top off his revolver. Less gasses will come back through the firing pin hole.
The typical single shot shotgun firing pin is full length. When you push it down with hammer before rebound, or with a stick (with breach open) what you see is what you have. (You cannot push it further into the frame with a toothpick and see it come out further at the breach end) So the question is why a "floating" or "inertia" firing pin that either does not stick out when hammer down flush before rebounding (1911 45), or sticks out only slightly (new S&W revolvers). Sure they are used in numerous semi autos. Not just the 1911 45 auto. One article even claims the AK47 uses an inertia firing pin (that travels forward after being hit by the hammer and impacts the primer with its own weight).
So, whereas I completely believe the machining process is easier with a firing pin that does not travel at an arc. A frame mounted regular pin similar to single shot shotgun would seem logical to me, at first glance.
Either way the damage to firing pin holes seen in old often dry fired revolvers, with hammer falling at an arc, now ends.
No longer will the ridge from outward peening of the firing pin hole penetrate into a just fired shells primer, preventing cylinder rotation for next shot. Or even cause enough binding to make first shot hard or impossible. (Anyone who does thousands and thousands of dry-fire snaps in older revolvers should run his finger tip over the firing pin hole before reloading and putting it away after each session).
(What does just 15 snaps a day or 100 a week for 52 weeks add up to? There are target shooters and combat shooters who do this, most love the 1911 45 auto with its level, inertia firing pin perhaps).
So, most people do not extensively dry fire revolvers. Safety wise we can either assume the people who buy police and military handguns are educated idiots easily duped or we look harder. About 40 years ago I read that S&W lost a navy contract in (1905?) when a revolver was dropped on a ship and a sailor shot in leg. I have not looked inside old guns but the article indicated (if memory serves) that the "rebound slide" that cams the hammer back and lifts hammer block in place dates to that time (or maybe just the hammer block?).
Note number six in below diagram. And note the pin number 31 that moves the hammer block back in position, number 48. (If I remember that date correctly the last time a S&W revolver was dropped and fired was well over 100 years ago)
Smith and Wesson Model 29 Parts Diagram - Smith & Wesson Model 29 Exploded View - Shooting Photo Galleries
When you empty and dry fire the newer floating firing pin revolvers, and an old hammer attached model, side by side not much is obvious at first. Then you put a pencil down the barrel eraser first, after cocking (again be sure it is empty) and see how far the pencil travels upward. Much further with old models. Not much with the newer models. So what is the good news?
So lets talk examining the primer after shooting.
I assume the good news is that the idiots that overcharge hand loads (instead of buying a bigger gun) have less to work with as the shell rebounds against the firing pin and weight of hammer in the old, verses the shell (again pushed forward by impact of pin) slamming back against only the light firing pin of the new. The primer will look more normal now and far less likely to rupture. Rebounding shell against the weight of the hammer is no longer an issue. Thin cheap primer material from foreign sources less scary.
And if it does rupture it is extremely unlikely any gasses will make it in the small firing pin hole around the small part, or around the fatter part of the firing pin, back around where firing pin gets small again, and out around the fatter hammer surface, toward the shooters face. (Also, the firing pin being pushed back by gasses no doubt seals the back shoulder)
(No I am not an engineer. I have occasionally examined old guns. The worst firing pin hole damage was on an aluminum frame chiefs special that was being sold used in 1970 before the steel bushings were being put around the hole. Another was a stainless steel .357 that was elongated downward - I assume do to the spring under the firing pin pushing up on the back pointing front of firing pin slightly downward, or at bottom of its normal wobble).
I am not a gunsmith and I hope gunsmiths here, that have seen many more old guns than I, will give a more complete description.
Years ago, I have never seen a problem with a new or well maintained S&W revolver that had fired American made cartridges or careful reloads. So I prefer the old models in new condition.
Next best, for me, would be the old full length, frame mounted firing pin used in single shot shotguns or single shot pistols. Perhaps if I was still shooting .357 I would like the idea of the fired shell now rebounding against just the weight of the firing pin?
I am in favor of most new machining steps that keep costs down. And Alloys & Polimers that keep weight down. All my guns have or have had something trivial that I do not like. Usually the hand grips. I guess I am in favor of new firing pins that might make new hand loaders or cheap cartridges or primers safer?
Definitely safer to the reloaded who accidentally double charges a shell and blows the top off his revolver. Less gasses will come back through the firing pin hole.
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While I am not sure about everything else posted in the preceding post by Delos, I am sure about the internal safety issue and would, therefore, like to "set the record straight."
Prior to introduction of the current hammer block, S&W had a couple of safety features to protect against firing in the event the revolver was dropped. In no particular order, the rebound slide has a hump which prevents the hammer from forward movement, and the revolvers, prior to WWII, had a hammer block mounted in a slot in the sideplate.
This is probably better described in Roy Jinks book and elsewhere, but basically, a sailor dropped a Victory model on a steel deck of ship and it discharged. Mr. Wesson himself examined the situation and directed the engineers to immediately introduce a more positive hammer block. This they did, and the current design was born. Victory models already in production had an "S" added to their serial numbers at the end, if memory serves, and Victory models produced after the engineering change had an "S" placed at the beginning of the serial numbers. Naturally, the "S" stood for safety.
The new hammer block was positively operated by a pin on the rebound slide and it had a block of steel that extended across the face of the hammer. Thus, the new hammer block was different both in its method of operation and in the amount of the hammer face actually blocked by the steel itself.
Unlike a "transfer bar" type of mechanism, the S&W mechanism puts that steel in front of the hammer in the rest position, and it moves out of the way when the trigger is pulled fully to the rear. If the trigger moves forward, the hammer block moves into its blocking position, which is why it is vital when decocking an S&W revolver that the user release the trigger the instant the user begins the controlled release under thumb control of the hammer. Doing so allows the hammer block to function as designed. Done properly, even if the hammer slips from your grasp (sweaty, oily or bloody hands), the revolver will not discharge as the hammer block is able to move into position IF the trigger is not held back. Thus, when decocking, always release the trigger and let it move forward as you start the hammer down.
Thus, S&W revolvers still have the hump on the rebound which helps to stop the hammer moving forward from inertia. Since WWII, S&W revolvers have also had the new style hammer block to prevent the firing pin from reaching the primer in the event something (often a drop or something causing a blow to the hammer) overcomes that hump on the rebound causing the hammer to move forward.
Note that the Centennial models do not have the hammer block as their hammers are incapable of receiving a blow since they are fully enclosed inside the frame. All other revolvers in the line have the new style hammer block.
To summarize, S&Ws had a hammer block in the slide before the engineering change to the Victory model in WWII. After WWII, all S&Ws, except the fully enclosed hammer Centennials, got the new style rebound operated hammer block which had been introduced on the Victory models during WWII. S&W revolvers had the hump on the rebound slide which prevents the hammer moving forward by inertia both before and after WWII. That hump is obviously not enough to prevent firing if something causes the hammer to overcome the rebound slide hump (usually a blow to the hammer caused by a drop from a sufficient height). There has, by the way, been some discrepancy on this forum concerning the distance the revolver fell which caused the redesign. Some have contended it was a drop to the deck on which the soldier stood, while others contend it was a drop to a deck below. I cannot remember without additional research, and it does not matter anyway as Mr. Wesson himself was convinced that the hump on the rebound designed to prevent inertia firing and the partial hammer block in the slide was not enough to insure that the revolvers would only discharge with a trigger pull. If Mr. Wesson himself felt so, enough said. Note that in the past some gunsmiths would remove the hammer block in hope of one less bit of friction. Based upon the re-design during WWII, I do not believe Mr. Wesson would approve of this really terrible idea. There are those on this forum that have argued until they are "blue in the face" that the whole redesign undertaken by S&W in WWII was unnecessary, that removal of the hammer block is acceptable, that the hump on the rebound slide is enough, that for a "range gun" the hammer block is not necessary, etc. Such thought goes against the facts. S&W would not have undertaken a mid-war redesign had it not been necessary, and anyone arguing to the contrary these days either does not want to let the facts get in the way of a strongly held, but incorrect, belief or such persons are just plain irresponsible. Enough said on that as well.
Prior to introduction of the current hammer block, S&W had a couple of safety features to protect against firing in the event the revolver was dropped. In no particular order, the rebound slide has a hump which prevents the hammer from forward movement, and the revolvers, prior to WWII, had a hammer block mounted in a slot in the sideplate.
This is probably better described in Roy Jinks book and elsewhere, but basically, a sailor dropped a Victory model on a steel deck of ship and it discharged. Mr. Wesson himself examined the situation and directed the engineers to immediately introduce a more positive hammer block. This they did, and the current design was born. Victory models already in production had an "S" added to their serial numbers at the end, if memory serves, and Victory models produced after the engineering change had an "S" placed at the beginning of the serial numbers. Naturally, the "S" stood for safety.
The new hammer block was positively operated by a pin on the rebound slide and it had a block of steel that extended across the face of the hammer. Thus, the new hammer block was different both in its method of operation and in the amount of the hammer face actually blocked by the steel itself.
Unlike a "transfer bar" type of mechanism, the S&W mechanism puts that steel in front of the hammer in the rest position, and it moves out of the way when the trigger is pulled fully to the rear. If the trigger moves forward, the hammer block moves into its blocking position, which is why it is vital when decocking an S&W revolver that the user release the trigger the instant the user begins the controlled release under thumb control of the hammer. Doing so allows the hammer block to function as designed. Done properly, even if the hammer slips from your grasp (sweaty, oily or bloody hands), the revolver will not discharge as the hammer block is able to move into position IF the trigger is not held back. Thus, when decocking, always release the trigger and let it move forward as you start the hammer down.
Thus, S&W revolvers still have the hump on the rebound which helps to stop the hammer moving forward from inertia. Since WWII, S&W revolvers have also had the new style hammer block to prevent the firing pin from reaching the primer in the event something (often a drop or something causing a blow to the hammer) overcomes that hump on the rebound causing the hammer to move forward.
Note that the Centennial models do not have the hammer block as their hammers are incapable of receiving a blow since they are fully enclosed inside the frame. All other revolvers in the line have the new style hammer block.
To summarize, S&Ws had a hammer block in the slide before the engineering change to the Victory model in WWII. After WWII, all S&Ws, except the fully enclosed hammer Centennials, got the new style rebound operated hammer block which had been introduced on the Victory models during WWII. S&W revolvers had the hump on the rebound slide which prevents the hammer moving forward by inertia both before and after WWII. That hump is obviously not enough to prevent firing if something causes the hammer to overcome the rebound slide hump (usually a blow to the hammer caused by a drop from a sufficient height). There has, by the way, been some discrepancy on this forum concerning the distance the revolver fell which caused the redesign. Some have contended it was a drop to the deck on which the soldier stood, while others contend it was a drop to a deck below. I cannot remember without additional research, and it does not matter anyway as Mr. Wesson himself was convinced that the hump on the rebound designed to prevent inertia firing and the partial hammer block in the slide was not enough to insure that the revolvers would only discharge with a trigger pull. If Mr. Wesson himself felt so, enough said. Note that in the past some gunsmiths would remove the hammer block in hope of one less bit of friction. Based upon the re-design during WWII, I do not believe Mr. Wesson would approve of this really terrible idea. There are those on this forum that have argued until they are "blue in the face" that the whole redesign undertaken by S&W in WWII was unnecessary, that removal of the hammer block is acceptable, that the hump on the rebound slide is enough, that for a "range gun" the hammer block is not necessary, etc. Such thought goes against the facts. S&W would not have undertaken a mid-war redesign had it not been necessary, and anyone arguing to the contrary these days either does not want to let the facts get in the way of a strongly held, but incorrect, belief or such persons are just plain irresponsible. Enough said on that as well.
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Delos
Member
Value of inertia firing pin more than drop safety?
Thank you very much Shawn.
So I am only safe in saying that "no Smith & Wesson revolver made since WW2 has accidentally fired from dropping. (Over 65 years?)
Back to inertia (or floating) firing pins for a second.
Everyone has seen a billiard ball hit another, and then that ball hit another. Each one using its own inertia for the next hit.
The first time I read about inertia firing pins, then racked back the slide on a 1911 45 auto, and then used my thumb nail to push down the firing pin level with the hole. And noticed the other end of the firing pin was not sticking out of the breach face…… I had to stare at it awhile.
This was before whatever modern firing pin locks added to new models for whatever real or imagined reason. Maybe someone fired a round from an old one with a weak firing pin return spring and looked at next cartridge primer and saw a small indent from after the slide slammed forward and firing pin moved forward from slide-speed inertia? Maybe the new hotter loads with lighter faster bullets got someone's attention?
(If anyone knows I would like to know - I was not reading about 45 autos when the series 70 and 80 came out).
Anyway the 1911 45 is one of the most reliable guns in history and the firing pin does not reach from the hammer to primer. Meaning when the hammer is down it is completely safe. And when the hammer is cocked it is at the wrong angle for dropping on concrete to effect anything. Then when the thumb safety is on……
One gun writer claimed some mathematician had calculated that it would need to be dropped from a (ten ?) story building directly onto the muzzle for the firing pin itself to possibly fire the cartridge.
My opinion involving any "advantage" to inertia firing pins in "revolver" situations gets equally curious. When a hand loader picks up his just fired brass and examines the primer he expects to see a nice indent in the primer with no rupture or flattening or flowing back around firing pin. Or so I have read - all mine have looked overly normal when I bothered to look.
So my assumption and belief is more complex. I have measured and watched the play or distance between revolver cartridge and breach face.
Perhaps 40 years ago I read an article claiming an old very loose revolver had gone full auto. The claim was that when the cylinder moved forward from hammer strike, then as it fired it came back fast enough to re-cock the hammer, and of course the trigger was all the way back so it would fire several rounds (yawn - boring, I have trouble imagining the cylinder being pushed forward before primer fires).
However the cartridge is in its forward position in the holster. In an old rather loose revolver when it is drawn from holster and fired downhill a bit, the cartridge is probably still forward. So I must conclude when the cartridge is fired it pushes back on the hammer at some small measurable level (When firing pin is attached to hammer). (Naturally as the brass shell expands it grips the sides of the chamber very briefly as pressure rises and falls? That and the pressure in the barrel would push the cylinder back quickly).
I must assume and believe that the average person examining his fired shells does not know how deep the firing pin indentation was when fired -- or how much deeper it got afterward when the shell pushed back against the firing pin and the attached hammers weight. It seems logical that one would need to fire an empty but primed shell to use as a standard, then any extra depth should be the shell rebounding against hammer weight?
Big advantage to inertia firing pin?
Like springs are designed to last years. Revolver hammers and attached firing pins must have been designed to compensate for increasing looseness over time, and/or variations in manufacture or individual machinists eyes and abilities. Before computer operated machinery?
The inertia firing pin has only its own weight, so the ability to travel further as needed is no big issue, I must assume. The strike on the primer will always be the same. And the lighter faster hammers should have shorter lock time. (Between trigger pulled and ignition).
So my answer to the original posters question is that I am beginning to like the new firing pin. But I notice in the gun magazine articles that the debate over the new models of the 1911 45 auto firing pin is still going strong after over 100 years. Some manufactures have lighter or different metals in their 1911 firing pins for good sounding reasons.
Sometimes being on the right side of Darwin and Murphy is choosing the company with the best engineers and batting average. Choosing a handgun that is still around after 100 years is never wrong unless the owner abuses it in some old, new, or interesting way.
When anti lock automobile brakes and seatbelts were new I hated them. Now I would not be without them.
And I am having real trouble choosing between S&W's new 1911 45 auto and the S&W M&P 45 auto, on my short list of next purchases.
If you guys would quit showing pictures of beautiful .357 revolvers I could get this done. And maybe in a few months I can answer your question with more than opinions.
Thank you very much Shawn.
So I am only safe in saying that "no Smith & Wesson revolver made since WW2 has accidentally fired from dropping. (Over 65 years?)
Back to inertia (or floating) firing pins for a second.
Everyone has seen a billiard ball hit another, and then that ball hit another. Each one using its own inertia for the next hit.
The first time I read about inertia firing pins, then racked back the slide on a 1911 45 auto, and then used my thumb nail to push down the firing pin level with the hole. And noticed the other end of the firing pin was not sticking out of the breach face…… I had to stare at it awhile.
This was before whatever modern firing pin locks added to new models for whatever real or imagined reason. Maybe someone fired a round from an old one with a weak firing pin return spring and looked at next cartridge primer and saw a small indent from after the slide slammed forward and firing pin moved forward from slide-speed inertia? Maybe the new hotter loads with lighter faster bullets got someone's attention?
(If anyone knows I would like to know - I was not reading about 45 autos when the series 70 and 80 came out).
Anyway the 1911 45 is one of the most reliable guns in history and the firing pin does not reach from the hammer to primer. Meaning when the hammer is down it is completely safe. And when the hammer is cocked it is at the wrong angle for dropping on concrete to effect anything. Then when the thumb safety is on……
One gun writer claimed some mathematician had calculated that it would need to be dropped from a (ten ?) story building directly onto the muzzle for the firing pin itself to possibly fire the cartridge.
My opinion involving any "advantage" to inertia firing pins in "revolver" situations gets equally curious. When a hand loader picks up his just fired brass and examines the primer he expects to see a nice indent in the primer with no rupture or flattening or flowing back around firing pin. Or so I have read - all mine have looked overly normal when I bothered to look.
So my assumption and belief is more complex. I have measured and watched the play or distance between revolver cartridge and breach face.
Perhaps 40 years ago I read an article claiming an old very loose revolver had gone full auto. The claim was that when the cylinder moved forward from hammer strike, then as it fired it came back fast enough to re-cock the hammer, and of course the trigger was all the way back so it would fire several rounds (yawn - boring, I have trouble imagining the cylinder being pushed forward before primer fires).
However the cartridge is in its forward position in the holster. In an old rather loose revolver when it is drawn from holster and fired downhill a bit, the cartridge is probably still forward. So I must conclude when the cartridge is fired it pushes back on the hammer at some small measurable level (When firing pin is attached to hammer). (Naturally as the brass shell expands it grips the sides of the chamber very briefly as pressure rises and falls? That and the pressure in the barrel would push the cylinder back quickly).
I must assume and believe that the average person examining his fired shells does not know how deep the firing pin indentation was when fired -- or how much deeper it got afterward when the shell pushed back against the firing pin and the attached hammers weight. It seems logical that one would need to fire an empty but primed shell to use as a standard, then any extra depth should be the shell rebounding against hammer weight?
Big advantage to inertia firing pin?
Like springs are designed to last years. Revolver hammers and attached firing pins must have been designed to compensate for increasing looseness over time, and/or variations in manufacture or individual machinists eyes and abilities. Before computer operated machinery?
The inertia firing pin has only its own weight, so the ability to travel further as needed is no big issue, I must assume. The strike on the primer will always be the same. And the lighter faster hammers should have shorter lock time. (Between trigger pulled and ignition).
So my answer to the original posters question is that I am beginning to like the new firing pin. But I notice in the gun magazine articles that the debate over the new models of the 1911 45 auto firing pin is still going strong after over 100 years. Some manufactures have lighter or different metals in their 1911 firing pins for good sounding reasons.
Sometimes being on the right side of Darwin and Murphy is choosing the company with the best engineers and batting average. Choosing a handgun that is still around after 100 years is never wrong unless the owner abuses it in some old, new, or interesting way.
When anti lock automobile brakes and seatbelts were new I hated them. Now I would not be without them.
And I am having real trouble choosing between S&W's new 1911 45 auto and the S&W M&P 45 auto, on my short list of next purchases.
If you guys would quit showing pictures of beautiful .357 revolvers I could get this done. And maybe in a few months I can answer your question with more than opinions.
I remember reading somewhere that brevity is the soul of wit.
Interesting to me is that I have never heard anyone complain about the firing pin being mounted on the frame on Colt Pythons.
Delos
Member
Jack Hammer end shake
But, but, but, I was not trying to be overly brief or overly witty.
Pull back on the cylinder of any well used revolver's cylinder and see how much the gap between cylinder and barrel enlarges (end shake).
Notice the springs keep the cylinder forward. When the handgun fires the shell and cylinder must travel backward. This means it pushes against the firing pin and attached hammer.
Maybe someone with a slow motion camera will get us some pictures. Maybe some bright person will put some paraffin wax behind the cylinder and measure it before and after. (Auto shops still have plastic gauge for measuring connecting rod bearings - it probably goes by another name nowdays)
No reason for me to do all the work also. Admit it….. The inertia firing pin is really logical. For at least two reasons. (Dry firing flash hole damage the other)
Put a piece of copper wire behind the cylinder of a revolver with lots of end shake.
With spring tension pushing cylinder forward, and barrel pressure when fired jamming it backward, it must be like an automatic hammer in an old blacksmith shop.
But, but, but, I was not trying to be overly brief or overly witty.
Pull back on the cylinder of any well used revolver's cylinder and see how much the gap between cylinder and barrel enlarges (end shake).
Notice the springs keep the cylinder forward. When the handgun fires the shell and cylinder must travel backward. This means it pushes against the firing pin and attached hammer.
Maybe someone with a slow motion camera will get us some pictures. Maybe some bright person will put some paraffin wax behind the cylinder and measure it before and after. (Auto shops still have plastic gauge for measuring connecting rod bearings - it probably goes by another name nowdays)
No reason for me to do all the work also. Admit it….. The inertia firing pin is really logical. For at least two reasons. (Dry firing flash hole damage the other)
Put a piece of copper wire behind the cylinder of a revolver with lots of end shake.
With spring tension pushing cylinder forward, and barrel pressure when fired jamming it backward, it must be like an automatic hammer in an old blacksmith shop.
Skeetr57
Member
I don't think that the frame mounted firing pin on S&W revolvers are inertia firin5 pins. They are too light for that. I have a number of S&W revolvers with frame mounted firing pins, such as old Safety Hammerless models, a M53, a M547, an M40 and the newest, an M940. On every one of them, if you dry fire it and hold the trigger back while looking through the gap between the cylinder and frame at the rear, the firing pin is plainly forward, until the trigger is released. That is not true with an inertia firing pin in the 1911, or semiautomatic and pump shotguns like the Remington 1100 and 870, because their firing pins are heavy enough to fire the primer when given a sufficiently strong blow from the hammer.
You were successful.
gr7070
Member
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Can you expand join that?
Sure. Wm Shakespeare wrote it about long-winded folks who ramble on and are unable to make a point, or wander from topic to topic, as displayed above.
Polonius:
My liege, and madam, to expostulate
What majesty should be, what duty is,
What day is day, night night, and time is time,
Were nothing but to waste night, day, and time;
Therefore, since brevity is the soul of wit,
And tediousness the limbs and outward flourishes,
I will be brief. Your noble son is mad. . . .
Hamlet Act 2, scene 2, 86–92
Polonius, right-hand man of Hamlet's stepfather, King Claudius, has been employed to spy on the prince and report on his very odd behavior. As Polonius begins to deliver to the king and queen the results of his investigation, he embarks on this windy preface. Besides being nonsensical, his speech is self-contradictory: he wastes plenty of time denouncing the time wasted by rhetorical speechifying.
"Brevity is the soul of wit" has become a standard English proverb; in the process, its context has been somewhat neglected. Polonius, though he has high opinions indeed of his "wit" (that is, acumen), is the least brief and one of the least "witty" characters in the play. Freud aptly referred to Polonius as "the old chatterbox" in Jokes and their Relation to the Unconscious.
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Delos
Member
I will get you some measurements
It is true that the firing pin sticks out a little on my 638-3. And there is very little headspace behind the cartridge that is under the hammer.
However when you push the hammer end of the firing pin way in with a toothpick it goes way out the firing pin hole, about as far as a hammer mounted firing pin?
If I had a primed (otherwise empty) shell I would push the back of the firing pin level with frame to see if it fires or leaves any mark on primer.
When I get a decent feeler gauge I will try to estimate how far it sticks out with cylinder open, and how much headspace behind shell.
Right now, to my eyes, the indention in a fired primer looks deeper than the amount the firing pin sticks out the breach face.
It is true that the firing pin sticks out a little on my 638-3. And there is very little headspace behind the cartridge that is under the hammer.
However when you push the hammer end of the firing pin way in with a toothpick it goes way out the firing pin hole, about as far as a hammer mounted firing pin?
If I had a primed (otherwise empty) shell I would push the back of the firing pin level with frame to see if it fires or leaves any mark on primer.
When I get a decent feeler gauge I will try to estimate how far it sticks out with cylinder open, and how much headspace behind shell.
Right now, to my eyes, the indention in a fired primer looks deeper than the amount the firing pin sticks out the breach face.
Delos
Member
638-3 firing pin with old eyesight
With my old eyesight, and a metric feeler gauge I measure the firing pin sticking out of my model 638-3 breach face about .70 mm (with hammer down)
My on-line metric to inches calculator says that equals .0276 inches. (28 thousandths?)
It might be slightly more. I put the feeler gauge beside the firing pin and could not feel it when running finger from the feeler gauge. Looking hard with a good led flashlight behind it there might be a sharp tip sticking up. It all looks small and sharp.
My model 60-7 has a much fatter firing pin and it sticks out about 1.05 mm which is about .0413 inches (41 thousandths?).
When I push it with a toothpick the firing pin on the 638-3 sticks out noticeably further than the hammer mounted firing pin on my 60-7 (my wife is not real patient with the toothpick in the firing pin hole and flashlight thing).
But my fingernail passing over the 41 thousandths of gauges used on the 60-7 and solidly hitting the extra length of firing pin pushed out with toothpick on 638-3, and visual inspection tells me the "floating" firing pin in my 638-3 has much longer travel than the hammer mounted pin on the 60-7 (If it is an inertia firing pin).
(When pushed from hammer side with toothpick like some of us did when checking 1911 45 autos with inertia firing pins).
With my old eyesight, and a metric feeler gauge I measure the firing pin sticking out of my model 638-3 breach face about .70 mm (with hammer down)
My on-line metric to inches calculator says that equals .0276 inches. (28 thousandths?)
It might be slightly more. I put the feeler gauge beside the firing pin and could not feel it when running finger from the feeler gauge. Looking hard with a good led flashlight behind it there might be a sharp tip sticking up. It all looks small and sharp.
My model 60-7 has a much fatter firing pin and it sticks out about 1.05 mm which is about .0413 inches (41 thousandths?).
When I push it with a toothpick the firing pin on the 638-3 sticks out noticeably further than the hammer mounted firing pin on my 60-7 (my wife is not real patient with the toothpick in the firing pin hole and flashlight thing).
But my fingernail passing over the 41 thousandths of gauges used on the 60-7 and solidly hitting the extra length of firing pin pushed out with toothpick on 638-3, and visual inspection tells me the "floating" firing pin in my 638-3 has much longer travel than the hammer mounted pin on the 60-7 (If it is an inertia firing pin).
(When pushed from hammer side with toothpick like some of us did when checking 1911 45 autos with inertia firing pins).
Delos
Member
Floating firing pins, Inertia firing pins?
I spent some time last night reading the definition of Floating Firing Pins and Inertia Firing Pins.
If memory serves an Inertia Firing pin is not long enough to touch hammer and primer at the same time. It does have a return spring so it can stick out enough that the hammer has something to hit. (Think 1911 45 auto)
A Floating Firing pin has no return spring. Apparently they get lost easily in military field inspection conditions. (Or are useful for full auto?). So they made harder primers for those weapons to fire. (It seems obvious to me that the floating firing pin is longer than an Inertia Firing Pin (With no return spring how else would the hammer hit it with weapon pointing downward? Unless it was slightly longer so contact with the hard primer pushed it back in position)?
More information needed. Obviously there are exceptions.
SAAMI
FIRING-PIN, FLOATING
A type of firing-pin which is unrestrained by a spring or other mechanical means.
FIRING-PIN, INERTIA
A type of firing-pin in which the forward movement is restrained until it receives the energy from a hammer blow. It is slightly recessed in the breech face before being struck by the hammer and is shorter in length than the housing in which it is contained. Upon hammer impact, it flies forward using only its own kinetic energy to fire the primer.
This is also worth reading.
Slamfire : definition of Slamfire and synonyms of Slamfire (English)
I spent some time last night reading the definition of Floating Firing Pins and Inertia Firing Pins.
If memory serves an Inertia Firing pin is not long enough to touch hammer and primer at the same time. It does have a return spring so it can stick out enough that the hammer has something to hit. (Think 1911 45 auto)
A Floating Firing pin has no return spring. Apparently they get lost easily in military field inspection conditions. (Or are useful for full auto?). So they made harder primers for those weapons to fire. (It seems obvious to me that the floating firing pin is longer than an Inertia Firing Pin (With no return spring how else would the hammer hit it with weapon pointing downward? Unless it was slightly longer so contact with the hard primer pushed it back in position)?
More information needed. Obviously there are exceptions.
SAAMI
FIRING-PIN, FLOATING
A type of firing-pin which is unrestrained by a spring or other mechanical means.
FIRING-PIN, INERTIA
A type of firing-pin in which the forward movement is restrained until it receives the energy from a hammer blow. It is slightly recessed in the breech face before being struck by the hammer and is shorter in length than the housing in which it is contained. Upon hammer impact, it flies forward using only its own kinetic energy to fire the primer.
This is also worth reading.
Slamfire : definition of Slamfire and synonyms of Slamfire (English)
