Transfer Bar Safety?
- Thread starter rc
- Start date
Which one does a 686 use? I believe the colt I am buying has the same thing. When the hammer is cocked on the colt and you look down you can see the little bar wiggle back and forth and the hammer can only hit a primer if the trigger is pulled. I'm trying to figure out if this .32 long revolver is strong enough to be converted to factory .32 mag or if it's too weak to bother. If it's a 60 or 70's era gun the chances of convertability are much higher. If it's a 30's era gun, it's much less likely to be possible. If the frame will take .38+P I'm sure it would work. If the frame only takes 32-20 and .38S&W then that's a whole nother story. Thanks for the help. Is there a websight with serial number ranges for colt revolvers or someplace that talks about the evolution of revolver safety mechanisms? Thanks, rc
Mike Irwin
Staff
The first transfer bar system was used on Iver Johnson handguns at the turn of the century.
CR Sam,
The S&W hammer block and a transfer bar are two TOTALLY different creatures.
In the transfer bar system, the bar has to be up to transfer the force of the hammer to the firing pin, which is frame mounted.
In the S&W hammer block system, the bit that looks like a transfer bar has to be DOWN, out of the path of the hammer, to allow the hammer, with the firing pin mounted in the nose, to fire the cartridge.
RC,
The 686 uses the system I've described for S&W.
And, as I mentioned over in your thread on the .32 Colt, it is NOT NOT NOT STRONG ENOUGH to convert to .32 Magnum.
Your Colt is likely 50 years old or older, and doesn't have the heat treating necessary to handle the higher pressure.
CR Sam,
The S&W hammer block and a transfer bar are two TOTALLY different creatures.
In the transfer bar system, the bar has to be up to transfer the force of the hammer to the firing pin, which is frame mounted.
In the S&W hammer block system, the bit that looks like a transfer bar has to be DOWN, out of the path of the hammer, to allow the hammer, with the firing pin mounted in the nose, to fire the cartridge.
RC,
The 686 uses the system I've described for S&W.
And, as I mentioned over in your thread on the .32 Colt, it is NOT NOT NOT STRONG ENOUGH to convert to .32 Magnum.
Your Colt is likely 50 years old or older, and doesn't have the heat treating necessary to handle the higher pressure.
From what I understand there were some post war police positives in .32 New Police. I'm sure the post war metals were much stronger than pre war. I need to figure out what other cartridges were chambered in the same frame when my gun was made but I'm having trouble locating serial number ranges and don't have any books on the subject here to date approximate manufacture. I thought the safety mechanism might give me a clue as to the age. If anyone has a colt collectors book and would be willing to look up the approximate age of my revolver it is SN 4955XX. I'm just exploring the possibilities for this revolver. If I load the long warm I want there to be plenty of margin for safety. I probably won't convert it to mag but I'd sure like to know if other cartridges in the 16,000 to 18,000 cup range were chambered in the same frame. Thanks, rc
Mike Irwin
Staff
RC,
Yes, there were some post-war PPs made, but don't count on them being "stronger" than the pre-war models.
Both S&W and Colt came out of the war with stocks of the small-frame revolvers left over from pre-war days. These were parts that had been made prior to the war and warehoused (a common practice, to batch manufacture parts). Given the nature of the national emergency, neither company concentrated very much on .32s during the war years.
Also, it's not a given that the new heat treating methods would have been applied to the older models, especially those firing relatively low intensity cartridges such as the .32 Long.
I'm seeing red lights all across the dive board on this one.
Really, just stick with the .32 Long. I've got an older S&W I-frame (1916-17 manufacture) that is just a TON of fun to shoot.
It's got a broken mainspring right now (snapped right at the strain screw), but I've done a bit of loading for it in the past, and it's FUN to shoot. No blast, no recoil, and more power than a .22.
Yes, there were some post-war PPs made, but don't count on them being "stronger" than the pre-war models.
Both S&W and Colt came out of the war with stocks of the small-frame revolvers left over from pre-war days. These were parts that had been made prior to the war and warehoused (a common practice, to batch manufacture parts). Given the nature of the national emergency, neither company concentrated very much on .32s during the war years.
Also, it's not a given that the new heat treating methods would have been applied to the older models, especially those firing relatively low intensity cartridges such as the .32 Long.
I'm seeing red lights all across the dive board on this one.
Really, just stick with the .32 Long. I've got an older S&W I-frame (1916-17 manufacture) that is just a TON of fun to shoot.
It's got a broken mainspring right now (snapped right at the strain screw), but I've done a bit of loading for it in the past, and it's FUN to shoot. No blast, no recoil, and more power than a .22.
Hammer blocks and transfer bars both have extremely low rates of failures...there's more or less no reason to pick a gun based on it having one or the other...I certainly wouldn't.
If a transfer bar "breaks off", the gun cannot fire. If a hammer block fails, it can leave the gun in a "no safety at all" mode similar to an 1873 Colt SAA.
In a hammer block gun with a hammer-mounted firing pin, the firing pin is somewhat more "exposed" and can break off. I had a Rossi .357 many years ago that had bad metallurgy in the firing pins, it broke two. I considered trying to have an S&W pin mounted in there, but it was too different. I had it fixed one last time in warrantee, then sold it.
Supposedly, a slightly lighter mainspring can be done in a hammer-block gun with firing pin on hammer. In a transfer bar setup, it's hammer-hits-bar-hits-firing-pin and all those "mechanical linkages" add up to extra friction. I don't think it's a major thing though.
Jim
If a transfer bar "breaks off", the gun cannot fire. If a hammer block fails, it can leave the gun in a "no safety at all" mode similar to an 1873 Colt SAA.
In a hammer block gun with a hammer-mounted firing pin, the firing pin is somewhat more "exposed" and can break off. I had a Rossi .357 many years ago that had bad metallurgy in the firing pins, it broke two. I considered trying to have an S&W pin mounted in there, but it was too different. I had it fixed one last time in warrantee, then sold it.
Supposedly, a slightly lighter mainspring can be done in a hammer-block gun with firing pin on hammer. In a transfer bar setup, it's hammer-hits-bar-hits-firing-pin and all those "mechanical linkages" add up to extra friction. I don't think it's a major thing though.
Jim
4thHorseman
New member
Hammer bar safety
From what I have read Colt was the first to introduce the hammer bar "transfer bar" safety with the Colt Python. If the firing pin is frame mounted, it has a hammer bar "tranfer bar" safety normally, if it has a hammer mounted firing pin, it usually has a hammer block safety. Along with that Colt's new idea, came some other ideas that were new to the indrustry at that time.
Hammer blocks have been out on Smith and Wesson's for near a century I believe.
Smith and Wesson hammer block must be pulled down to be able to fire. However on some Colts (ie; Magnum Carry and the like), the hammer bar "tranfer bar" must be moved up next to the "firing pin" be able to fire. The hammer strikes the transfer bar and the transfer bar then strkes the firing pin.
If the hammer block was left out on a S&W the revolver would always be in the unsafe mode. The firing pin would extrude through the frame. If it was left out on the Colt newer style, the revolver could not be fired. Not all Colts are like this though, some are similiar to S&W.
I don't believe one is any better than the other, just different ways to accomplish the same thing.
From what I have read Colt was the first to introduce the hammer bar "transfer bar" safety with the Colt Python. If the firing pin is frame mounted, it has a hammer bar "tranfer bar" safety normally, if it has a hammer mounted firing pin, it usually has a hammer block safety. Along with that Colt's new idea, came some other ideas that were new to the indrustry at that time.
Hammer blocks have been out on Smith and Wesson's for near a century I believe.
Smith and Wesson hammer block must be pulled down to be able to fire. However on some Colts (ie; Magnum Carry and the like), the hammer bar "tranfer bar" must be moved up next to the "firing pin" be able to fire. The hammer strikes the transfer bar and the transfer bar then strkes the firing pin.
If the hammer block was left out on a S&W the revolver would always be in the unsafe mode. The firing pin would extrude through the frame. If it was left out on the Colt newer style, the revolver could not be fired. Not all Colts are like this though, some are similiar to S&W.
I don't believe one is any better than the other, just different ways to accomplish the same thing.
Mike Irwin
Staff
4th Horseman,
"If the hammer block were left out on an S&W revolver, it would always be in the unsafe mode."
Well, not really correct...
The hammer block on a Smith & Wesson is there simply as a backup safety measure.
When the trigger is released on a post-WW II S&W, the hammer moves back and away from the frame and the firing pin out of contact with the cartridge and a hump on the rebound slide moves into position where it physically blocks the hammer from moving forward. The only way the hammer can move forward on an S&W revolver with the trigger released and the rebound slide in its relaxed position is if the hammer receives a crushing blow and is physically broken or bent.
This is why the L-shaped hammer block was installed; as a secondary safety measure.
This system replaced an older system in which the hammer block was part of the side plate. The movement of the rebound slide cammed the block out of the way of the hammer, allowing it to fall unimpeded.
The rebound slide didn't have the hump on it that would physically block the hammer.
The new system was introduced during the final years of World War II when S&W began to receive complaints that the hammer block could "freeze" and either render the gun inoperable if the block froze in the "on" position, or prone to firing if the hammer was struck because the block was frozen in the "off" position.
"If the hammer block were left out on an S&W revolver, it would always be in the unsafe mode."
Well, not really correct...
The hammer block on a Smith & Wesson is there simply as a backup safety measure.
When the trigger is released on a post-WW II S&W, the hammer moves back and away from the frame and the firing pin out of contact with the cartridge and a hump on the rebound slide moves into position where it physically blocks the hammer from moving forward. The only way the hammer can move forward on an S&W revolver with the trigger released and the rebound slide in its relaxed position is if the hammer receives a crushing blow and is physically broken or bent.
This is why the L-shaped hammer block was installed; as a secondary safety measure.
This system replaced an older system in which the hammer block was part of the side plate. The movement of the rebound slide cammed the block out of the way of the hammer, allowing it to fall unimpeded.
The rebound slide didn't have the hump on it that would physically block the hammer.
The new system was introduced during the final years of World War II when S&W began to receive complaints that the hammer block could "freeze" and either render the gun inoperable if the block froze in the "on" position, or prone to firing if the hammer was struck because the block was frozen in the "off" position.
Dfariswheel
New member
According to what I read about S&W history, a U.S. WWII sailor dropped a S&W 38 Victory model on the steel deck of a ship. The gun fired and a sailor was killed. S&W's president was VERY distressed that one of their guns had killed one of our own, and ordered a redesign that included a better safety system. Not because of lawyers and product liability, but because it was the thing to do. Different age, different men.
A hammer-block safety is a steel bar that must be moved OUT of the path of the hammer, so the hammer can move forward and strike the cartridge. This system was put into Colt revolvers in the late 1890's. This system is used in all Colt 'D, E&I, and New Service guns, also all S&W guns, irregardless of whether the firing pin is hammer or frame mounted.
A transfer bar safety is a flat steel bar that must be moved INTO the path of the hammer in order to fire the gun.
The bar transfers the hammer strike to the firing pin.
The Colt 'J, AA, SF, and Anaconda frames all use this system. In fact, all most ALL post 1970's DA revolvers use the transfer bar system.
The hammer-block system CAN fail or be defeated. (Years ago, target shooters routinely removed the safety assembly from Colt revolvers, in the belief that this gave a smoother trigger pull). The transfer bar cannot be defeated by removal, and is about as fool-proof as you can get.
A hammer-block safety is a steel bar that must be moved OUT of the path of the hammer, so the hammer can move forward and strike the cartridge. This system was put into Colt revolvers in the late 1890's. This system is used in all Colt 'D, E&I, and New Service guns, also all S&W guns, irregardless of whether the firing pin is hammer or frame mounted.
A transfer bar safety is a flat steel bar that must be moved INTO the path of the hammer in order to fire the gun.
The bar transfers the hammer strike to the firing pin.
The Colt 'J, AA, SF, and Anaconda frames all use this system. In fact, all most ALL post 1970's DA revolvers use the transfer bar system.
The hammer-block system CAN fail or be defeated. (Years ago, target shooters routinely removed the safety assembly from Colt revolvers, in the belief that this gave a smoother trigger pull). The transfer bar cannot be defeated by removal, and is about as fool-proof as you can get.
4thHorseman
New member
Mike Irwin, Thanks for the info on S&W. I was unaware of the rebound slide playing a part of the safety feature. I thought the block was the only thing stopping the firing pin from hitting the bullet primer.
I stand corrected. Thanks, I learn something new all the time on these boards.
I stand corrected. Thanks, I learn something new all the time on these boards.
Since Mike Irwin didn't say it, I will...
Iver Johnson's guns were marketed with the slogan, "Hammer the hammer", meaning that even if you pound on the cocked hammer with a hammer, and the gun's hammer falls, it still would not fire. It was famous worldwide and the US Postal Service would deliver mail to Iver Johnson with the addressee marked as, "Hammer the Hammer" or equivalent.
By the way, since I got on the topic of the US Postal service, one letter was once addressed to "Top Dog" in Washington DC. After some thought, it was delivered to Supreme Court Chief Justice Frankfurther.
Finally, regarding Mike's observation on the Rebound Slide's function, that is the safety feature deleted in the newer Taurus revolvers. Given the choice of design (I'm not talking about purchasing one) perference, I'd take S&W anyday over Taurus.
Iver Johnson's guns were marketed with the slogan, "Hammer the hammer", meaning that even if you pound on the cocked hammer with a hammer, and the gun's hammer falls, it still would not fire. It was famous worldwide and the US Postal Service would deliver mail to Iver Johnson with the addressee marked as, "Hammer the Hammer" or equivalent.
By the way, since I got on the topic of the US Postal service, one letter was once addressed to "Top Dog" in Washington DC. After some thought, it was delivered to Supreme Court Chief Justice Frankfurther.
Finally, regarding Mike's observation on the Rebound Slide's function, that is the safety feature deleted in the newer Taurus revolvers. Given the choice of design (I'm not talking about purchasing one) perference, I'd take S&W anyday over Taurus.
Mike Irwin
Staff
Gary,
I didn't say it because someone else here said it.
I used to have one of the old Iver Johnson "Hammer the Hammer" advertisements from the turn of the century. Unfortunatly, it disappeared during one of my moves.
I didn't say it because someone else here said it.
I used to have one of the old Iver Johnson "Hammer the Hammer" advertisements from the turn of the century. Unfortunatly, it disappeared during one of my moves.
Hi, guys,
Don't get the hammer block confused with the rebound mechanism. Both Colt's "Positive Safety" which gave its name to the "Police Postive" gun series and S&W's hammer block are totally independent of the rebound mechanism. On the newer (after about 1900) S&W, hammer rebound is caused by a rebound slide moving into place under the hammer and tilting it backward. The trigger spring is inside the rebound slide. On (all but the new) the Colts, rebound comes from the rebound lever, which is operated by the bottom part of the "V" main spring and whose front end operates the hand.
Rebound mechanisms were originally designed to be safety devices to prevent the hammer from resting on a primer, but are not proof against discharge if enough force is applied to the hammer. The hammerblocks or transfer bars provide additional safety.
S&W went through a couple of types of hammer blocks. The one immediately before the current type was operated by a ramp on the hand, not by the rebound lever. But it would fail if it stuck in the sideplate, and it was its own spring and subject to breakage. The current design cannot stick and does not depend on a spring.
Jim
Don't get the hammer block confused with the rebound mechanism. Both Colt's "Positive Safety" which gave its name to the "Police Postive" gun series and S&W's hammer block are totally independent of the rebound mechanism. On the newer (after about 1900) S&W, hammer rebound is caused by a rebound slide moving into place under the hammer and tilting it backward. The trigger spring is inside the rebound slide. On (all but the new) the Colts, rebound comes from the rebound lever, which is operated by the bottom part of the "V" main spring and whose front end operates the hand.
Rebound mechanisms were originally designed to be safety devices to prevent the hammer from resting on a primer, but are not proof against discharge if enough force is applied to the hammer. The hammerblocks or transfer bars provide additional safety.
S&W went through a couple of types of hammer blocks. The one immediately before the current type was operated by a ramp on the hand, not by the rebound lever. But it would fail if it stuck in the sideplate, and it was its own spring and subject to breakage. The current design cannot stick and does not depend on a spring.
Jim
Mike Irwin
Staff
"S&W's hammer block [is] totally independent of the rebound mechanism."
No, that's not the case. The loop on the bottom of the hammer block fits over a stud on the rebound slide -- the two work in concert.
Rearward travel of the rebound slide draws the hammer block out of the way of the hammer.
When the rebound slide travels forward, the hammer block is pushed back up between the hammer and the frame.
As for how Colts work, I'll take your word for it. I haven't had a Colt open in over 5 years.
"The one immediately before the current type was operated by a ramp on the hand, not by the rebound lever."
Whoops, my bad. It's been a long time since I've had my Regulation Police or 1917 apart.
No, that's not the case. The loop on the bottom of the hammer block fits over a stud on the rebound slide -- the two work in concert.
Rearward travel of the rebound slide draws the hammer block out of the way of the hammer.
When the rebound slide travels forward, the hammer block is pushed back up between the hammer and the frame.
As for how Colts work, I'll take your word for it. I haven't had a Colt open in over 5 years.
"The one immediately before the current type was operated by a ramp on the hand, not by the rebound lever."
Whoops, my bad. It's been a long time since I've had my Regulation Police or 1917 apart.