Trigger job on S&W
- Thread starter kv4v
- Start date
I think Kuhnhausen has a S&W book out at http://www.gunbooks.com
When I carried a S&W M-66 (dept. issue) I used to smooth up the action by taking the things apart and very lightly stonning the faces of all the flats and breaking the edges of the corners. Make the very, very very lightly breaking the edges.
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"If there be treachery, let there be jihad."
Ne Conjuge Nobiscum
When I carried a S&W M-66 (dept. issue) I used to smooth up the action by taking the things apart and very lightly stonning the faces of all the flats and breaking the edges of the corners. Make the very, very very lightly breaking the edges.
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"If there be treachery, let there be jihad."
Ne Conjuge Nobiscum
Mike Irwin
Staff
General action job on an S&W involves:
1. Replacing all of the springs with lighter springs by Wolff.
2. Stoning all mating surfaces smooth, including those on the frame itself.
3. (Sometimes done) Installing bearing washers on the hammer and trigger studs.
4. Retiming the action.
5. Stoning the single and double action sears so that the break is crisp, light, and consistent.
6. Lubricating properly.
As Jim mentioned, the Kuhnhausen book is by far the best on the subject.
Everything I leared about working on my S&W revolvers I learned from this book.
One of the truly great things is that if you learn how to do an action job on an N-frame, you know how to do the action job on just about every other S&W hand ejector ever made.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
1. Replacing all of the springs with lighter springs by Wolff.
2. Stoning all mating surfaces smooth, including those on the frame itself.
3. (Sometimes done) Installing bearing washers on the hammer and trigger studs.
4. Retiming the action.
5. Stoning the single and double action sears so that the break is crisp, light, and consistent.
6. Lubricating properly.
As Jim mentioned, the Kuhnhausen book is by far the best on the subject.
Everything I leared about working on my S&W revolvers I learned from this book.
One of the truly great things is that if you learn how to do an action job on an N-frame, you know how to do the action job on just about every other S&W hand ejector ever made.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
Careful with the lighter springs. Too light on the hammer and you can get misfires, too light on the rebound spring and your trigger reset will fail at the most embarassing times.
At least, you hope that embarassment is the worst consequence.
The best stone to use is a HARD Arkansas--the type that leave a mirror finish, rather than just a bright but matte polish.
Hammer and trigger surfaces are critical, as the *&* approach (and part of their success) to smooth triggers is to case-harden those parts. Notice the nice coloring? However, that is a surface hardening. Stone your way through that and you will then have a self-adjusting, constantly changing and potentially dangerous trigger mechanism.
At least, you hope that embarassment is the worst consequence.
The best stone to use is a HARD Arkansas--the type that leave a mirror finish, rather than just a bright but matte polish.
Hammer and trigger surfaces are critical, as the *&* approach (and part of their success) to smooth triggers is to case-harden those parts. Notice the nice coloring? However, that is a surface hardening. Stone your way through that and you will then have a self-adjusting, constantly changing and potentially dangerous trigger mechanism.
Good points, Cheapo.
At a recent range pin session, one fellow was bragging about the light DA pull on his 686. A gunsmith had worked it over and it was really light. I thought, and said, that it was too light and might not fire. I was thoroughly told off for my ignorance of the smith's great reputation. (I didn't tell him I have done trigger work on hundreds of S&W's.)
Then he stepped to the firing line, and clicked at the bowling pins. Strangely, not one fell to the reputation of his super gunsmith.
Jim
At a recent range pin session, one fellow was bragging about the light DA pull on his 686. A gunsmith had worked it over and it was really light. I thought, and said, that it was too light and might not fire. I was thoroughly told off for my ignorance of the smith's great reputation. (I didn't tell him I have done trigger work on hundreds of S&W's.)
Then he stepped to the firing line, and clicked at the bowling pins. Strangely, not one fell to the reputation of his super gunsmith.
Jim
Mike Irwin
Staff
AEM,[b/]
No, an action job as I have described will not require retiming the action. It's just one of those "extra step" things that can be done on a full-blown job. Because it is pretty precise work, though, it really adds to the cost of a complete action job.
JIM,
That's a very good idea that I've never seen mentioned. I don't think I would want to mill an area wider than about 1/3 of the length of the slide, and certainly not more than 1/2, and certainly no deeper than a few 100ths of an inch, just enough to get clearance. I could see it being very easy to put together a jig that would allow precise reduction using a stone.
CHEAPO,
You make a VERY good point about the rebound slide springs.
In some guns you HAVE to do an action job in order to use a lighter spring.
Wolff (through Brownell's) sells the packs with a reduced power main spring and 13, 14, and 15 pound rebound slide springs (I THINK the stock spring is probably about 18 pounds on most S&W guns).
I've had more than one gun that has had problems returning the trigger to battery with the 13 & 14 lb. springs installed.
Normally, though, a good action job to free up friction will allow the 13 lb. springs to function without a hitch.
I have the 13-lb. springs in both of my Model 19s and both of my Model 28s. One 19 and both 28s required me to do action jobs before I could use the 13 lb spring without the trigger hanging.
If ultimate reliability IS the issue, an action job coupled with the 15 lb spring is probably the way to go.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
No, an action job as I have described will not require retiming the action. It's just one of those "extra step" things that can be done on a full-blown job. Because it is pretty precise work, though, it really adds to the cost of a complete action job.
JIM,
That's a very good idea that I've never seen mentioned. I don't think I would want to mill an area wider than about 1/3 of the length of the slide, and certainly not more than 1/2, and certainly no deeper than a few 100ths of an inch, just enough to get clearance. I could see it being very easy to put together a jig that would allow precise reduction using a stone.
CHEAPO,
You make a VERY good point about the rebound slide springs.
In some guns you HAVE to do an action job in order to use a lighter spring.
Wolff (through Brownell's) sells the packs with a reduced power main spring and 13, 14, and 15 pound rebound slide springs (I THINK the stock spring is probably about 18 pounds on most S&W guns).
I've had more than one gun that has had problems returning the trigger to battery with the 13 & 14 lb. springs installed.
Normally, though, a good action job to free up friction will allow the 13 lb. springs to function without a hitch.
I have the 13-lb. springs in both of my Model 19s and both of my Model 28s. One 19 and both 28s required me to do action jobs before I could use the 13 lb spring without the trigger hanging.
If ultimate reliability IS the issue, an action job coupled with the 15 lb spring is probably the way to go.
------------------
Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
Hi, Mike,
Could we have a misunderstanding here? I mill the rebound slide lengthwise, leaving rails on either side. Cut away about 1/2 to 2/3 of the width from the middle. I know this is not very precise, but I have played with different dimensions, and am not sure it matters much. The cuts don't have to be deep (.005 will do), just enough so that part of the slide doesn't touch the frame or sideplate.
Jim
Could we have a misunderstanding here? I mill the rebound slide lengthwise, leaving rails on either side. Cut away about 1/2 to 2/3 of the width from the middle. I know this is not very precise, but I have played with different dimensions, and am not sure it matters much. The cuts don't have to be deep (.005 will do), just enough so that part of the slide doesn't touch the frame or sideplate.
Jim
Mike Irwin
Staff
Jim,
OK, I think you were talking about going lengthwise, and I was talking about going top to bottom.
Either would work.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
OK, I think you were talking about going lengthwise, and I was talking about going top to bottom.
Either would work.
------------------
Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
I always bevel the nose of the hammer block to allow it to slide up between the hammer & frame more easily. Do NOT make it thinner over its entire surface. Just bevel the nose & polish slick. Deburr & polish the track in the sideplate where it runs as well as the shaft of the hammer block. I also slightly bevel & polish the top of the rebound where it engages the foot of the hammer to ease the return. Do not lower the height of the top of the rebound. I also ream & polish the inside of the rebound spring tunnel. It is amazing how much drag can be eliminated here. This, too, is often a necessary step to allow the use of a lighter trigger return spring. The key to the trigger job is POLISH. You don't want to remove much material unless: (1) your gun is seriously out of spec, (2)you are an expert with years of experience & (3) you have a box full of spare parts.
Hi, BBBill,
Beveling the nose of the hammer block sounds OK but probably won't do any good, since the hammer should be out of the way before the block gets up that far. The rest sounds OK, including polishing the inside of the rebound slide. To lighten the mainspring, grind down the sides, not the back or front; do not turn out the spring tension screw as that will allow the tip of the spring to contact the hammer and interfere with it.
The trick to polishing, as you well note, is knowing where and how much to polish, especially on the case-hardened S&W parts.
Jim
Beveling the nose of the hammer block sounds OK but probably won't do any good, since the hammer should be out of the way before the block gets up that far. The rest sounds OK, including polishing the inside of the rebound slide. To lighten the mainspring, grind down the sides, not the back or front; do not turn out the spring tension screw as that will allow the tip of the spring to contact the hammer and interfere with it.
The trick to polishing, as you well note, is knowing where and how much to polish, especially on the case-hardened S&W parts.
Jim
Hello Jim!
I've found that the nose bevel on the hammer block is OCCASIONALLY necessary when you have a gun with a little tolerance stack up. The hammer block nose will stub against the underside of the hammer face below the hammer nose (firing pin for those of you that think in more normal terms)when the clearance between the hammer face and the stop surface in the frame is a little tight. I believe this lets the block slip in & start the hammer back. Especially just getting past the chin (corner) of the hammer face. Just something I've bumped into over the years. Anybody else? I've learned as much here as I have with my hands in the guts of a gun. Please share.
I've found that the nose bevel on the hammer block is OCCASIONALLY necessary when you have a gun with a little tolerance stack up. The hammer block nose will stub against the underside of the hammer face below the hammer nose (firing pin for those of you that think in more normal terms)when the clearance between the hammer face and the stop surface in the frame is a little tight. I believe this lets the block slip in & start the hammer back. Especially just getting past the chin (corner) of the hammer face. Just something I've bumped into over the years. Anybody else? I've learned as much here as I have with my hands in the guts of a gun. Please share.
Hi, BBBill,
Unless there is something wrong, though, like too much polishing of the top of the rebound slide, the hammer should be well out of the way of the hammer block. The block is not supposed to push the hammer back, it is only supposed to be there to keep the gun from firing if it is dropped on the hammer. The rebound slide cannot be depended on to prevent firing if the blow is hard enough to shear the hammer pin or break the hammer, while the hammer block will prevent firing even in those extreme cases.
BTW, I do not normally replace springs (unless I f*** up!). I modify the original springs as needed. I have seen too many failures with replacement springs, including those from a certain famous company. The gun I mentioned that "clicked" bowling pins until they didn't fall had a set of their springs, although I don't know what the "famous smith" had done to them.
Jim
[This message has been edited by Jim Keenan (edited October 05, 2000).]
Unless there is something wrong, though, like too much polishing of the top of the rebound slide, the hammer should be well out of the way of the hammer block. The block is not supposed to push the hammer back, it is only supposed to be there to keep the gun from firing if it is dropped on the hammer. The rebound slide cannot be depended on to prevent firing if the blow is hard enough to shear the hammer pin or break the hammer, while the hammer block will prevent firing even in those extreme cases.
BTW, I do not normally replace springs (unless I f*** up!). I modify the original springs as needed. I have seen too many failures with replacement springs, including those from a certain famous company. The gun I mentioned that "clicked" bowling pins until they didn't fall had a set of their springs, although I don't know what the "famous smith" had done to them.
Jim
[This message has been edited by Jim Keenan (edited October 05, 2000).]
You are absolutely right Jim. However, I've run across a few in the past that had a "proud" hammer face, frame seat, or some other out of spec/tolerance stack problem. I don't know of any way to isolate/identify this except a box of new replacement parts & a couple hours time. Could probably shorten the hammer block nose a bit or take a little off the hammer face. The top of the rebound slide had NOT been lowered. It is a tricky balancing act & you don't run across it often, but once in a while........S&W has let a few out that were off spec. The most glaringly noticeable was the run of 625s with the frame slot for the cylinder release cut wrong. They fit the factory releases to compensate. When some shooters starting replacing the releasrs with the Ed Brown release, it finally came to light. After a lot of checking, it was verified that it was the gun, not the aftermarket part.
This has digressed a bit from the original intent of this thread so I won't continue this line of thought. While you do occasionally find these problems, for the most part, an S&W trigger job is very straightforward as long as you follow some simple guidelines as listed earlier in the thread. My apologies for leading us off on a different path.
This has digressed a bit from the original intent of this thread so I won't continue this line of thought. While you do occasionally find these problems, for the most part, an S&W trigger job is very straightforward as long as you follow some simple guidelines as listed earlier in the thread. My apologies for leading us off on a different path.
Hi, kv4v,
To replace the rebound slide spring, remove the mainspring and hammer. Then pry the back end of the rebound slide up and off its post. Make sure to keep the spring under control.
Insert the new spring and compress the back end with a Philips screwdriver of appropriate size so that one of the flutes of the screwdriver tip fits over the post. Press the slide the rest of the way by hand. If necessary, use a small screwdriver through the slot to compress the spring further. (There is a tool for this if you plan to do it often, but the way I describe will work.)
Make sure the trigger strut is engaged with the rebound slide. Replace the hammer, and the main (hammer) spring. Do not tighten down the mainspring tension screw.
Replace the sideplate. Tighten the mainspring tension screw. Replace the grips.
Jim
To replace the rebound slide spring, remove the mainspring and hammer. Then pry the back end of the rebound slide up and off its post. Make sure to keep the spring under control.
Insert the new spring and compress the back end with a Philips screwdriver of appropriate size so that one of the flutes of the screwdriver tip fits over the post. Press the slide the rest of the way by hand. If necessary, use a small screwdriver through the slot to compress the spring further. (There is a tool for this if you plan to do it often, but the way I describe will work.)
Make sure the trigger strut is engaged with the rebound slide. Replace the hammer, and the main (hammer) spring. Do not tighten down the mainspring tension screw.
Replace the sideplate. Tighten the mainspring tension screw. Replace the grips.
Jim
Mike Irwin
Staff
Doc,
Replacing the rebound slide spring is pretty easy, actually.
1. Remove the side plate.
2. Remove the hammer spring.
3. Remove the hammer by pulling the trigger enough to release the hammer, then move the hammer back by hand. When it clears the frame, lift the hammer up off the hammer pivot stud.
(now comes the intersting part...)
4. With a flat bladed screwdriver, very gently lift up on the back of the rebound slide until the top coil of the spring clears the reboundslide retaining pin.
Go slowly! If you go too fast, and the spring completely clears the retaining pin, it will shoot out with pretty good force.
5. Take a shop rag to pad your thumb, and hold it over the rebound slide spring. The idea is to hold it in such a way that you won't have the spring come shooting out.
6. With your thumb in place, holding the spring to keep it from flying out, use the screwdriver to finish prying the rebound slide up and over the retaining pin.
7. Remove the rebound slide, and take the spring out of the slide.
Depending on the age of your gun, there MAY be a pin running through the center of the spring. Not all of them have this, though.
8. Put the new spring into the slide. Put the pin back into the spring, if one was there.
9. Another tricky part. You need a Phillips screwdriver with a head that is just slightly larger than the loops on the spring.
10. Set the rebound slide into the frame so that it is properly aligned with the ball stud on the trigger.
11. Put the Phillips into the rear of the spring and push in to compress the spring so that it will clear the rebound slide pin.
12. Push down on the rebound slide so that the bottom loop of the spring catches on the rebound slide pin.
13. Remove the Phillips screw driver, and using the flat bladed screwdriver, push the top loop of the spring in so that it clears the rebound slide pin, and push the rebound slide down until it is fully seated.
14. Replace the hammer.
15. Replace the side plate.
And you're done.
It sound difficult at first, but once you've done it a couple of times, it gets a LOT easier and quicker.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
Replacing the rebound slide spring is pretty easy, actually.
1. Remove the side plate.
2. Remove the hammer spring.
3. Remove the hammer by pulling the trigger enough to release the hammer, then move the hammer back by hand. When it clears the frame, lift the hammer up off the hammer pivot stud.
(now comes the intersting part...)
4. With a flat bladed screwdriver, very gently lift up on the back of the rebound slide until the top coil of the spring clears the reboundslide retaining pin.
Go slowly! If you go too fast, and the spring completely clears the retaining pin, it will shoot out with pretty good force.
5. Take a shop rag to pad your thumb, and hold it over the rebound slide spring. The idea is to hold it in such a way that you won't have the spring come shooting out.
6. With your thumb in place, holding the spring to keep it from flying out, use the screwdriver to finish prying the rebound slide up and over the retaining pin.
7. Remove the rebound slide, and take the spring out of the slide.
Depending on the age of your gun, there MAY be a pin running through the center of the spring. Not all of them have this, though.
8. Put the new spring into the slide. Put the pin back into the spring, if one was there.
9. Another tricky part. You need a Phillips screwdriver with a head that is just slightly larger than the loops on the spring.
10. Set the rebound slide into the frame so that it is properly aligned with the ball stud on the trigger.
11. Put the Phillips into the rear of the spring and push in to compress the spring so that it will clear the rebound slide pin.
12. Push down on the rebound slide so that the bottom loop of the spring catches on the rebound slide pin.
13. Remove the Phillips screw driver, and using the flat bladed screwdriver, push the top loop of the spring in so that it clears the rebound slide pin, and push the rebound slide down until it is fully seated.
14. Replace the hammer.
15. Replace the side plate.
And you're done.
It sound difficult at first, but once you've done it a couple of times, it gets a LOT easier and quicker.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.
I know one way NOT to do a trigger job, but it deals with trying to rescue a $25.00 boat anchor. When I built my FrankenSmith, it was a learning experience, and I'd never wish it on my worst enemy. I'd recommend a later Model 10, at least. 1941 lockwork is a good bit different in dimensions, I learned that I couldn't fit the roller action trigger kit in the M1905 frame, duh! It all worked out ok with judicious stoning, shims, even the fitment of the Model 10 .38 Special cylinder and crane to replace the .38 S&W cylinder. When it came time to put a trigger overtravel stop in, I learned a really neat trick - instead of drilling and tapping the trigger for a screw, or welding a blob on the back of the trigger and filing to length, I put a piece of brass pin stock, filed to proper trigger feel length, inside the rebound slide's spring! Here's the result, note the quick cylinder release...
http://www.geocities.com/gew98.geo/ppcpropointleftplonk2.jpg
http://www.geocities.com/gew98.geo/ppcpropointleftplonk2.jpg
Good news everyone. I bought the Kuhnhausen S&W book and the Wolff reduced power springs and between the book and all your suggestions I managed to do the job. I have 4 N framed S&Ws. Three of them have had action jobs by a gunsmith. One of the gunsmith jobs is better that the one I did but mine is better that two of the jobs the other guy did! That is almost a miracle considering I only have one eye and I'm 71 years old to boot! Thanks again. Doc
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Is that a pistol in your pocket or are you just glad to see me? .... Mae West
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Is that a pistol in your pocket or are you just glad to see me? .... Mae West