Trigger over-travel stop
- Thread starter labnoti
- Start date
- Status
UncleEd
Member
On S&W a trigger stop was often incorporated at the
back of the trigger guard opening, appears as an oval
protrusion, and was held in place by a screw revealed when
the side plate was removed. For combat guns, i.e.
meaning police, it was advised to remove it to preclude
the stop coming loose and possibly impeding rearward
travel of the trigger.
On guns set sought for bullseye shooting, where no trigger
stop was apparent from the factory, one was stuck on the
back of the trigger.
As for the pin inside the trigger return spring on N frames,
I've never given it a thought but at least it's not going to
loosen or fall off. And if I lost the pin, didn't care.
But I'm no bullseye shooter.
back of the trigger guard opening, appears as an oval
protrusion, and was held in place by a screw revealed when
the side plate was removed. For combat guns, i.e.
meaning police, it was advised to remove it to preclude
the stop coming loose and possibly impeding rearward
travel of the trigger.
On guns set sought for bullseye shooting, where no trigger
stop was apparent from the factory, one was stuck on the
back of the trigger.
As for the pin inside the trigger return spring on N frames,
I've never given it a thought but at least it's not going to
loosen or fall off. And if I lost the pin, didn't care.
But I'm no bullseye shooter.
My choice has always been the solid pin the factory used to install in the rebound slide or the solid pin many revolversmiths fit into the rear of the trigger. and file to a perfect fit. Both of those can never fail, get out of adjustment or change in any way. "Adjustable" means it can come out of adjustment and prevent the gun from firing when you desperately need it to fire. For a gun used for serious business that is a Very Big Deal. Fixed and solid is what you want on a business gun. For a range gun any kind of stop will suffice.
Dan-O
Member
I would think it’s fixed.....
SteadyD
Member
- Joined
- May 5, 2017
- Messages
- 1,747
There’s a trigger stop on the back of the trigger that contacts the frame when the trigger is pulled.
Driftwood Johnson
Member
Howdy
For what its worth, I'm pretty sure Smith and Wesson only installed this style of trigger stop on revolvers with adjustable sights. This is my old Model 17-3.
A couple of K-22s. you can just barely see the trigger stops peeking out behind the triggers.
Short and long Model 17s.
Model 19-3.
Model 14-3.
K-32.
K-38 Combat Masterpiece.
My point is I don't think I've ever seen a trigger over travel stop in any S&W with fixed sights. Which makes sense in a way. The guns with adjustable sights could be used in competition, so the over travel stop might help a little bit with precise target shooting. While a fixed sight revolver was more likely to be carried as a duty weapon, which is probably why there was no over travel stop on them.
The only revolver in my collection with the rod inside the rebound slid return spring is this Model 617-6. The rod below the rebound slide and its spring is the trigger over travel stop.
For what its worth, I'm pretty sure Smith and Wesson only installed this style of trigger stop on revolvers with adjustable sights. This is my old Model 17-3.
A couple of K-22s. you can just barely see the trigger stops peeking out behind the triggers.
Short and long Model 17s.
Model 19-3.
Model 14-3.
K-32.
K-38 Combat Masterpiece.
My point is I don't think I've ever seen a trigger over travel stop in any S&W with fixed sights. Which makes sense in a way. The guns with adjustable sights could be used in competition, so the over travel stop might help a little bit with precise target shooting. While a fixed sight revolver was more likely to be carried as a duty weapon, which is probably why there was no over travel stop on them.
The only revolver in my collection with the rod inside the rebound slid return spring is this Model 617-6. The rod below the rebound slide and its spring is the trigger over travel stop.
Pardon me, I'm going in the other room to either scream or cry, not sure which. Gosh would I like one of them.
I know my 14-3 has a trigger stop, can't remember any others off hand.
BobWright
Member
When I was into target shooting, some of the shooters had trigger stops installed on their revolvers. S&W target guns had them built in, but many shooters shot older Colts that had no trigger stops. So they had several methods. One was to drill and tap the trigger for a set screw. For awhile there was an adjustuble trigger stop for Ruger Blackhawks that replaced the trigger spring on Three Screw Models.
I never found trigger stops to be any great benefit as most trigger springs were of sufficient resistance for me. But then I was not the greatest shot on the line, either.
And there was always that one shooter who always had the latest gimmick, the utmost reloading equipment, the most expensive spotting scope, and the gun case made of select hardwood. Usually couldn't shoot worth a hoot and a holler, but was always free with advice.
I never found trigger stops to be any great benefit as most trigger springs were of sufficient resistance for me. But then I was not the greatest shot on the line, either.
And there was always that one shooter who always had the latest gimmick, the utmost reloading equipment, the most expensive spotting scope, and the gun case made of select hardwood. Usually couldn't shoot worth a hoot and a holler, but was always free with advice.
stonebuster
Member
I own two 40 year old Dan Wesson revolvers with an over travel set screw on the back of the trigger. Some DW models have them on the frame. They do get out of adjustment eventually causing the trigger to fail to return. Blue locktite would probably fix it. They're range toys so not a big issue.
In the OP, I was wondering what the relative merits of the roll-pin on the back of the trigger, and the bar inside the rebound slide were. As it turns out, we can also find trigger over-travel stops machined into the trigger guard, and that stops on the trigger and on the trigger guard can be adjustable, but there is a concern with them falling out of adjustment.
S&W does not machine the adjustable stops on the trigger guard of the frame anymore. I believe they don't do this because it adds considerable machine time to production costs and there are two simpler alternatives:
S&W's mold for their MIM triggers includes a boss on the back to be drilled for a roll pin. That pin can be ground or filed down to the desired length, and these pins are often featured on Performance Center guns.
S&W also puts a round bar in the rebound slide through the ID of the rebound spring on some models. This bar also acts as a trigger overtravel stop. It is omitted on the Performance Center guns that feature the roll pin on the back of the trigger.
Is the roll pin on the trigger better than the bar? Or is the roll pin just accessorizing eye-candy?
I have a revolver with each. The one with the bar inside the rebound slide has more overtravel, whereas the one with the pinned trigger has less overtravel. I wonder if a longer bar could be used to reduce the overtravel of the barred gun or if there is some inherent limitation, hence the pinned trigger on models where less overtravel is sought after.
I also wonder if there is some risk of pinned triggers failing and causing a FTF -- and if S&W doesn't put them on standard models for that reason. They seem to put them on models oriented toward competition shooting. They do, however, put them on the L Comp and 19 Carry Comp which appear to be intended for concealed carry. If the pins did back out a little, it seems more likely they would prevent the single-action sear from engaging and not very likely to stop DA.
S&W does not machine the adjustable stops on the trigger guard of the frame anymore. I believe they don't do this because it adds considerable machine time to production costs and there are two simpler alternatives:
S&W's mold for their MIM triggers includes a boss on the back to be drilled for a roll pin. That pin can be ground or filed down to the desired length, and these pins are often featured on Performance Center guns.
S&W also puts a round bar in the rebound slide through the ID of the rebound spring on some models. This bar also acts as a trigger overtravel stop. It is omitted on the Performance Center guns that feature the roll pin on the back of the trigger.
Is the roll pin on the trigger better than the bar? Or is the roll pin just accessorizing eye-candy?
I have a revolver with each. The one with the bar inside the rebound slide has more overtravel, whereas the one with the pinned trigger has less overtravel. I wonder if a longer bar could be used to reduce the overtravel of the barred gun or if there is some inherent limitation, hence the pinned trigger on models where less overtravel is sought after.
I also wonder if there is some risk of pinned triggers failing and causing a FTF -- and if S&W doesn't put them on standard models for that reason. They seem to put them on models oriented toward competition shooting. They do, however, put them on the L Comp and 19 Carry Comp which appear to be intended for concealed carry. If the pins did back out a little, it seems more likely they would prevent the single-action sear from engaging and not very likely to stop DA.
Driftwood Johnson
Member
Howdy Again
One thing you need to understand is that Smith and Wesson has been modifying their designs for a long, long time. Sometimes the changes were made to make the gun better, sometimes they were made to make the gun less expensive to produce. The second type of engineering change is often described as 'driving out the cost to manufacture'. Driving out the cost to manufacture may or may not make the gun easier to use, but manufacturers like it because it saves them money when the gun is made. These cost savings may or may not be passed on to the consumer. If the cost savings are not passed on, the money saved stays in the manufacturer's pocket.
Smith and Wesson manufactured its first revolver in 1857, a tiny 22 Rimfire Tip Up model. By 1860 the design had gone through five engineering changes. Some to make the gun easier to use, some to drive out some of the cost to manufacture. This little guy is a No. 1 Tip Up 1st Issue, 5th Type. It left the factory in 1859. In all there were six versions of this little revolver made before it went out of production in 1860, to be replaced by the No. 1 Tip Up 2nd Issue. Some of those six versions made the gun easier to use, some simply drove out some of the cost to manufacture.
Don't get me wrong, there is nothing wrong with exploring ways to drive out some of the cost to manufacture. Any company that does not do so is cutting its own throat, because a competitor will probabaly find a way to make a similar product cheaper.
A number of years ago Smith and Wesson went to a new process for making many of their small parts called Metal Injection Molding (MIM). Powdered metal is suspended in a binding material. The material is fed into an injection molding machine not much different than an injection molding machine for plastics. The part is molded, then it is baked to drive out the binding material. Once in this state the part is heated just enough so that the individual powdered metal particles bind to each other. The part is not heated enough to melt the particles, it is just heated enough so the individual particles bind on their surfaces to neighboring particles. This is a very cost effective way to make small parts, much less expensive than traditional methods of forging and machining parts from solid metal.
You will hear MIM parts vilified on many gun boards, but it is a perfectly acceptable way to make parts and drive the cost out of manufacturing. Even a very traditional guy such as myself recognizes the legitimacy of MIM parts.
Anyway, sometime in the late 1990s S&W started using MIM parts in their revolvers. They also made many significant changes in the way frames were machined at the same time.
My point is eliminating the trigger over travel stop did not save much money. In the overall picture of manufacturing a S&W revolver, I would be surprised if much more than a single dollar was driven out of the cost to manufacture a revolver by eliminating the trigger over travel stop.
Let's look at some photos. Here is the trigger over travel stop on a Model 17-3 made in 1975. All that had to be done to include it was to drill and tap the hole for the screw, and cut a slit for the stop to sit in. This revolver was made in the early days of CNC machining, drilling and tapping the hole and cutting the slit probably only took a few extra lines of code in the CNC program and would involve a tool change for the slit. I have not taken that over travel stop out in a long time, and I am not going to do it now, but I would not be surprised if the threaded hole was tapped with the same tap as the side plate hole next to it.
Here is the same area of the frame on a Model 617-6 made in 2003. Yes, this revolver is full of MIM parts, but that's not what we're talking about here. Clearly, there is no tapped hole for the trigger stop and no slit to place it in. Many years ago I spent some time working with CNC machines, and I'll bet it would only take a CNC programmer a few minutes to add the lines of code needed to put the tapped hole and the slit back in. Once the code has been modified, that part of the job is done. I can't imagine it would take very long to make the extra cuts, particularly when you consider how long it takes to make the complete frame in the first place. The other factor is the elimination of parts needed to assemble the gun. Yup, one screw and one trigger stop are no longer needed. Since these parts were either purchased in bulk, or manufactured in the S&W factory, again not a very big cost savings. And lastly, yup probably about two minutes or so for an experienced assembler to install the extra parts.
My point is, very significant cost savings happened when S&W redesigned their frames in the late 1990s and early 2000s and started using MIM parts. Two cost savings can be seen in the photo above, the studs that the hammer, trigger, and bolt pivot on. Simple pins with parallel sides, vs the shaped studs that can be seen in the Model 17 above. But in the overall scheme of things, eliminating the trigger stop was a very small drop in a pretty big bucket.
Regarding mounting a roll pin in a MIM trigger, I am not aware of that. Perhaps you could elaborate.
Here are two photos of the triggers in the Model 17-3 and the Model 617-6. The 617-6 trigger is a MIM part, the 17-3 trigger is a traditional machined part.
In each photo, the MIM trigger is on the left and the machined trigger is on the right.
The machined trigger is an assembly, consisting of the hand, the trigger, the rod that engages the rebound slide and an internal spring. The parts are held in place by four pins. This trigger assembly needed to be assembled by positioning the parts and driving in the pins.
The MIM trigger only needs the hand an the internal spring pinned in place, the rod is a separate part that is loose and does not need to be assembled into the trigger, it is simply placed in the trigger when the gun is assembled. A classic example of how redesigning parts can save money.
Anyway, the shapes of the parts are very similar. Can you explain where the boss is for the roll pin?
Is the trigger different than what I am showing here?
By the way, I don't know off the top of my head how many S&W revolvers I have with trigger over travel stops in them. Obviously I have a few. None of them have ever come loose and prevented the gun from firing.
Knock on wood.
One thing you need to understand is that Smith and Wesson has been modifying their designs for a long, long time. Sometimes the changes were made to make the gun better, sometimes they were made to make the gun less expensive to produce. The second type of engineering change is often described as 'driving out the cost to manufacture'. Driving out the cost to manufacture may or may not make the gun easier to use, but manufacturers like it because it saves them money when the gun is made. These cost savings may or may not be passed on to the consumer. If the cost savings are not passed on, the money saved stays in the manufacturer's pocket.
Smith and Wesson manufactured its first revolver in 1857, a tiny 22 Rimfire Tip Up model. By 1860 the design had gone through five engineering changes. Some to make the gun easier to use, some to drive out some of the cost to manufacture. This little guy is a No. 1 Tip Up 1st Issue, 5th Type. It left the factory in 1859. In all there were six versions of this little revolver made before it went out of production in 1860, to be replaced by the No. 1 Tip Up 2nd Issue. Some of those six versions made the gun easier to use, some simply drove out some of the cost to manufacture.
Don't get me wrong, there is nothing wrong with exploring ways to drive out some of the cost to manufacture. Any company that does not do so is cutting its own throat, because a competitor will probabaly find a way to make a similar product cheaper.
A number of years ago Smith and Wesson went to a new process for making many of their small parts called Metal Injection Molding (MIM). Powdered metal is suspended in a binding material. The material is fed into an injection molding machine not much different than an injection molding machine for plastics. The part is molded, then it is baked to drive out the binding material. Once in this state the part is heated just enough so that the individual powdered metal particles bind to each other. The part is not heated enough to melt the particles, it is just heated enough so the individual particles bind on their surfaces to neighboring particles. This is a very cost effective way to make small parts, much less expensive than traditional methods of forging and machining parts from solid metal.
You will hear MIM parts vilified on many gun boards, but it is a perfectly acceptable way to make parts and drive the cost out of manufacturing. Even a very traditional guy such as myself recognizes the legitimacy of MIM parts.
Anyway, sometime in the late 1990s S&W started using MIM parts in their revolvers. They also made many significant changes in the way frames were machined at the same time.
My point is eliminating the trigger over travel stop did not save much money. In the overall picture of manufacturing a S&W revolver, I would be surprised if much more than a single dollar was driven out of the cost to manufacture a revolver by eliminating the trigger over travel stop.
Let's look at some photos. Here is the trigger over travel stop on a Model 17-3 made in 1975. All that had to be done to include it was to drill and tap the hole for the screw, and cut a slit for the stop to sit in. This revolver was made in the early days of CNC machining, drilling and tapping the hole and cutting the slit probably only took a few extra lines of code in the CNC program and would involve a tool change for the slit. I have not taken that over travel stop out in a long time, and I am not going to do it now, but I would not be surprised if the threaded hole was tapped with the same tap as the side plate hole next to it.
Here is the same area of the frame on a Model 617-6 made in 2003. Yes, this revolver is full of MIM parts, but that's not what we're talking about here. Clearly, there is no tapped hole for the trigger stop and no slit to place it in. Many years ago I spent some time working with CNC machines, and I'll bet it would only take a CNC programmer a few minutes to add the lines of code needed to put the tapped hole and the slit back in. Once the code has been modified, that part of the job is done. I can't imagine it would take very long to make the extra cuts, particularly when you consider how long it takes to make the complete frame in the first place. The other factor is the elimination of parts needed to assemble the gun. Yup, one screw and one trigger stop are no longer needed. Since these parts were either purchased in bulk, or manufactured in the S&W factory, again not a very big cost savings. And lastly, yup probably about two minutes or so for an experienced assembler to install the extra parts.
My point is, very significant cost savings happened when S&W redesigned their frames in the late 1990s and early 2000s and started using MIM parts. Two cost savings can be seen in the photo above, the studs that the hammer, trigger, and bolt pivot on. Simple pins with parallel sides, vs the shaped studs that can be seen in the Model 17 above. But in the overall scheme of things, eliminating the trigger stop was a very small drop in a pretty big bucket.
Regarding mounting a roll pin in a MIM trigger, I am not aware of that. Perhaps you could elaborate.
Here are two photos of the triggers in the Model 17-3 and the Model 617-6. The 617-6 trigger is a MIM part, the 17-3 trigger is a traditional machined part.
In each photo, the MIM trigger is on the left and the machined trigger is on the right.
The machined trigger is an assembly, consisting of the hand, the trigger, the rod that engages the rebound slide and an internal spring. The parts are held in place by four pins. This trigger assembly needed to be assembled by positioning the parts and driving in the pins.
The MIM trigger only needs the hand an the internal spring pinned in place, the rod is a separate part that is loose and does not need to be assembled into the trigger, it is simply placed in the trigger when the gun is assembled. A classic example of how redesigning parts can save money.
Anyway, the shapes of the parts are very similar. Can you explain where the boss is for the roll pin?
Is the trigger different than what I am showing here?
By the way, I don't know off the top of my head how many S&W revolvers I have with trigger over travel stops in them. Obviously I have a few. None of them have ever come loose and prevented the gun from firing.
Knock on wood.
Machining that intricate shape on the back of the trigger would be involved if it was machined from bar stock, but it's quite simple to do that once and then make a mold for MIM. The question is why don't they always install that roll pin in every model instead of just some Performance Center models? Why do they sometimes put a round bar in the rebound slide instead?
With respect to the cost of machining the old-style over-travel stops on the frame, I think part of the cost is the QC rejects and warranty returns. The bean counters know how much machine time that tapped hole and slot cost, and how much the screw and cam cost, and also how many frames were rejected for bad holes and slots, and how many warranty returns came in when QC missed it. You might be right that it was still a drop in the bucket, but drops add up. If it wasn't driving out the cost that motivated the change, what do you think it was? It seems to me that when they went to MIM triggers, they realized they could create a shape that wasn't practical before. That's why they molded that boss on there. It adds no cost to the trigger at all until they drill and pin it. One hole and a roll pin is less than a tapped hole, slot, screw, and cam. But the bar inside the rebound slide is an even simpler solution.
With respect to the cost of machining the old-style over-travel stops on the frame, I think part of the cost is the QC rejects and warranty returns. The bean counters know how much machine time that tapped hole and slot cost, and how much the screw and cam cost, and also how many frames were rejected for bad holes and slots, and how many warranty returns came in when QC missed it. You might be right that it was still a drop in the bucket, but drops add up. If it wasn't driving out the cost that motivated the change, what do you think it was? It seems to me that when they went to MIM triggers, they realized they could create a shape that wasn't practical before. That's why they molded that boss on there. It adds no cost to the trigger at all until they drill and pin it. One hole and a roll pin is less than a tapped hole, slot, screw, and cam. But the bar inside the rebound slide is an even simpler solution.
Driftwood Johnson
Member
Howdy Again
Thanks for the photo.
In this photo the MIM Model 617 trigger is on the left, the traditionally machined Model 17 trigger is on the right.
As you can see, there is a rectangular rib, or bar molded into the rear of the MIM hammer. That appears to me to be the spot where the hole is drilled for the roll pin. The strut that interacts with the rebound slide is slightly obscuring the view. The older style trigger looks more like it was broached than machined. It certainly was not polished up because polishing that surface would serve no purpose, and besides the rear of the trigger is normally pretty hidden from view. I have seen this on a lot of old S&W triggers.
Here is another view of the 617 trigger. I have a Model 686-6 and the trigger looks identical. I suspect that rather than the rib being there for the roll pin, it is there to add a little bit of rigidity to the trigger. Designing a casting is a bit different than designing a machined part. One has to be careful not to leave too much metal thickness. Too much metal remaining can cause shrinkage when the metal cools, causing sunken dimples on the surface. I strongly suspect that is why the rear of these triggers are relieved at the rear, to prevent dimples forming on the sides as the metal cools. Molding parallel ribs on the rear of the trigger solves that problem nicely, reducing the overall thickness of the part while helping with the rigidity. I have no idea when S&W started drilling the hole for the roll pin, perhaps they planned it all along, so that is why the rectangular rib is there, or perhaps one day one of the engineers said, "Hey, why don't we drill a hole in that rectangular rib for a roll pin?" No idea if the chicken came before the egg or vice versa. I do know this revolver was made in 2003. When did they start putting in the roll pin?
Anybody?
Bueller?
P.S. a lot of the time today no prototype part has to be machined up first before making a MIM part. One of the mechanical designers I used to work with designed parts for MIM and various other types of molding and casting processes all the time. He would create the part in 3D CAD, make it a little bit bigger than the finished part to allow for shrinkage, then send the 3D file off to the manufacturer. They would create the mold directly from his 3D part, no machining involved at all. He is the guy who showed me how he would have to relieve the surfaces of the part to avoid dimples being formed when the part cooled.
I can see you and I are going to argue until the cows come home about the cost to machine in or delete a specific feature. As I said, S&W has been building revolvers for over 160 years, and has oodles of experience driving cost out by tweaking the design. I can also tell you that in the 'old days', whenever that was, S&W had many in process inspection steps that would catch mistakes, often in time to save a part. Yes, today S&W has done away with most of those in process inspection steps and stuff gets out the door that never would have 40 or 50 or more years ago. It does seem like the customer is the final inspector today. But I strongly suspect that in the 'old days' whenever that was, not a whole lot of time and money was wasted rejecting parts outright. I'll bet a lot of them could be saved if caught in time.
It used to be said that S&W never wasted anything. Even boxes. Old printed boxes would be saved and have a new label slapped on them so they could be used for something other than what they were intended for.
Like this:
Thanks for the photo.
In this photo the MIM Model 617 trigger is on the left, the traditionally machined Model 17 trigger is on the right.
As you can see, there is a rectangular rib, or bar molded into the rear of the MIM hammer. That appears to me to be the spot where the hole is drilled for the roll pin. The strut that interacts with the rebound slide is slightly obscuring the view. The older style trigger looks more like it was broached than machined. It certainly was not polished up because polishing that surface would serve no purpose, and besides the rear of the trigger is normally pretty hidden from view. I have seen this on a lot of old S&W triggers.
Here is another view of the 617 trigger. I have a Model 686-6 and the trigger looks identical. I suspect that rather than the rib being there for the roll pin, it is there to add a little bit of rigidity to the trigger. Designing a casting is a bit different than designing a machined part. One has to be careful not to leave too much metal thickness. Too much metal remaining can cause shrinkage when the metal cools, causing sunken dimples on the surface. I strongly suspect that is why the rear of these triggers are relieved at the rear, to prevent dimples forming on the sides as the metal cools. Molding parallel ribs on the rear of the trigger solves that problem nicely, reducing the overall thickness of the part while helping with the rigidity. I have no idea when S&W started drilling the hole for the roll pin, perhaps they planned it all along, so that is why the rectangular rib is there, or perhaps one day one of the engineers said, "Hey, why don't we drill a hole in that rectangular rib for a roll pin?" No idea if the chicken came before the egg or vice versa. I do know this revolver was made in 2003. When did they start putting in the roll pin?
Anybody?
Bueller?
P.S. a lot of the time today no prototype part has to be machined up first before making a MIM part. One of the mechanical designers I used to work with designed parts for MIM and various other types of molding and casting processes all the time. He would create the part in 3D CAD, make it a little bit bigger than the finished part to allow for shrinkage, then send the 3D file off to the manufacturer. They would create the mold directly from his 3D part, no machining involved at all. He is the guy who showed me how he would have to relieve the surfaces of the part to avoid dimples being formed when the part cooled.
I can see you and I are going to argue until the cows come home about the cost to machine in or delete a specific feature. As I said, S&W has been building revolvers for over 160 years, and has oodles of experience driving cost out by tweaking the design. I can also tell you that in the 'old days', whenever that was, S&W had many in process inspection steps that would catch mistakes, often in time to save a part. Yes, today S&W has done away with most of those in process inspection steps and stuff gets out the door that never would have 40 or 50 or more years ago. It does seem like the customer is the final inspector today. But I strongly suspect that in the 'old days' whenever that was, not a whole lot of time and money was wasted rejecting parts outright. I'll bet a lot of them could be saved if caught in time.
It used to be said that S&W never wasted anything. Even boxes. Old printed boxes would be saved and have a new label slapped on them so they could be used for something other than what they were intended for.
Like this:
- Status