Single Action vs. Double Action

[Old Fuff]

Roman R.:It's handy (I've got one) but it's an awful lot like a bushing wrench for a 1911. Can use it if you've got it, but not dependent on it.

It's like a lot of specialized tools, jigs and fixtures used for working on S&W revolvers (as well as other guns, the 1911 pistol platform in particular). If you are experienced and nimble you can get along without most of them, or find your own way to a work-around. But if this isn't what you are you may find yourself turning the air blue as you try to find (whatever) that is somewhere on the floor or elsewhere. Then you have to take the time to order a replacement, pay for it - plus shipping - and wait for it to arrive.

One of the advantages of the previously mentioned manual is that it sometimes points out ways of doing things that will help to avoid this, and these "tricks" are seldom or ever mentioned by advisors on the Internet.

 

[mikemyers]

That's one of the real issues. If you're experienced, you can probably do most things, and know what not to do, but how do you get to be experienced without ever trying?

I suspect that several people here, especially you, could take this gun apart in your sleep, and have no more problems working on it than a kid putting a wheel back on his bicycle (back when kids knew which way to turn a wrench, at least).

I used to do a lot of mechanical things. A "friend" gave me a motorcycle wheel trueing stand, a wheel with a bent rim, along with a new rim and spokes, and told me to fix it. Eventually I learned how, and he started bringing me wheels to fix all the time. For a kid in college, it was a nice bit of income, as most people couldn't or didn't have the patience to do it.

Back to guns - how is anyone in this forum ever going to learn how to "do" things, without actually trying to "do" them? Just reading about it is only a start.

So, if you have the time and patience to type it all in here, and the desire to do so, how did you guys get to where you are now? Did you take classes? Did you just do it on your own, and eventually learn by experience what (and what not) to do?

I've always felt that if it was going to cost $XX to fix something once, but for the same $XX I could buy a tool to allow me to do it on my own, that was the better option much of the time. I almost always found someone who knew, to teach me how to do it properly. When I lived in Michigan, it was easy to find those people. Nowadays, I wonder if they still even exist - especially in Florida. Nobody seems to fix things nowadays, they just replace them.


OK, back to reality. I expect to read the entire manual, even if I don't understand much of it. Eventually it will probably all make sense. I also need to thank you guys, as working with the pieces now spread across my workbench, I have a FAR better idea of what goes on inside the gun than I ever had before. Animations are good, but actually seeing the pieces move around is much, much, more meaningful.

 

[MrBorland]

how did you guys get to where you are now?

By doing exactly what you're doing - reading a lot, asking questions, getting the right tools & references, opening a gun up and carefully watching how it works, taking it apart piece by piece. And before I modified or smoothed any part, I made darned sure that's what I really needed to be doing. And even then, I go slow, test often and step away when I need a break.

 

[mikemyers]

One by one, I've been looking over all the parts, especially those that might bind or interfere with another part. This one might explain why the gun feels so "rough" - your thoughts?



I assume the entire bottom surface shown in the photo should be equally smooth and shiny, while this part is apparently touching in one place, which explains all the wear.

I will try to find a way to take a photo of the mating surface in the gun; not sure how well it will come out.

 

[Old Fuff]

One technique (that nobody tells you) is to coat the parts is various places with an easy-to-remove-later dye called "Dykem." After reassembling the parts and cycling the action a few times the gun is disassembled again and note taken about where the dye has been rubbed off. This can be an enlightening experience, especially if you were about to polish something where it would have done absolutely no good. It can also tell you where parts are interfacing, as they should, or where they are not.

Actually some would tell you to polish the bottom of the rebound slide, but if you go through the case-hardened surface you will quickly be in trouble. On the other hand where you don't see a burnish mark the slide isn't touching the frame and causing any friction.

In this situation you can reassemble the trigger, rebound slide and spring (for this purpose a lighter one is fine) and then pull the trigger back and forth while feeling for unwanted resistance.

Still another alternative is to use lapping compound (available from Brownells) and lap both the rebound slide and frame. Assemble as above, but first coat the bottom of the rebound slide with lapping compound. The simply pull the trigger to lap the associated parts. Be sure to check the progress often and clean out all traces of lapping compound when you’re done.

At this point I wouldn’t be in a hurry to do anything but observing.

 

[mikemyers]

.........In this situation you can reassemble the trigger, rebound slide and spring (for this purpose a lighter one is fine) and then pull the trigger back and forth while feeling for unwanted resistance.......

As suggested earlier re-assembly of the gun is waiting for the spring tool from Brownells.

At this point I wouldn’t be in a hurry to do anything but observing.

More observing, but I don't know enough to realize if any of this is abnormal:


Sideplate, hasn't been touched since removal.



Shrapnel on the frame, where the rebound slide might be hitting it?



After cleaning - if I push on it, it actually does feel smoother! Not sure if this will matter.


I probably need to coat everything with a bit of oil - the humidity here is so high that the parts, sitting exposed like this, look like they are developing some rust.

 

[mikemyers]

Dykem in use......

Have any of you bought a machine like this, and used this technique to improve the trigger pull?

https://www.youtube.com/watch?v=HJ6Hb89lVXw


If I ever found a good gunsmith in Miami, is this the way he'd probably be improving the trigger?

 

[MrBorland]

First of all, the video suggests the quality of the (double) action is dictated solely by the interaction of the sears. That's a huge oversimplification, IMO. Look inside the gun as the action cycles, and you'll see a myriad of mating surfaces that have to be smooth & square to each other. You could likely ignore the sear surfaces altogether, focus on these surfaces, and still get a pretty nice action.

Secondly, unless I missed something, he only uses the jig to polish the single action sear on the trigger. These mating surfaces are tiny and knife-edged, which is why a jig is a good idea if you're going to touch a SA sear surface. The SA triggers on S&W revolvers are generally very good, though, so I wouldn't even touch the SA sear surfaces if it were me.

I'm not saying that jig's not useful - maybe it's a standard piece of equipment on pro gunsmiths tables - but I personally don't think it's needed to do a decent home action job.

 

[Old Fuff]

Unfortunately the video shows more then is explained.

I’ll start by saying that if the manual was available you’d know that all adjustment to the single-action trigger pull should be made to the trigger only, and not the full-cock notch on the hammer. There is no faster way to ruin a hammer then to fool with this notch, and Mr. Borland is absolutely right when he says that it shouldn’t be touched, and it is seldom necessary anyway.

Yes, most professional gunsmiths use jigs and fixtures to insure their work will be right, but most of what was shown has to do with smoothing the double – not single-action. Mr. Borland is incorrect when he underestimates the importance of fitting the double-action sear that is located in the front of the hammer. Since 1905 Smith & Wesson has had a unique double-action system that was more advanced then any other revolver of this kind, and recently Ruger copied it in their new-from-the-ground-up LCR revolver, that subsequently got rave reviews for its double-action trigger pull.

When the sideplate has been removed, cycle the hammer through a double-action stroke and carefully watch what happens.

As the trigger starts moving backwards a ledge at the top/rear come up and pushes on the bottom of the sear. This causes the hammer to also rotate backwards. About ¾ through the stroke the ledge has rotated far enough forward so that it no longer is against the sear (and at this point the hammer should fall, but it doesn’t). Instead, if the sear has been correctly fitted, a smaller ledge lower on the trigger picks up the hammer and causes it to continue on backwards until the second ledge rotates out of engagement and at this point the hammer is released and falls.

If all of this is going to happen with perfect smoothness some very critical fitting is necessary, especially between the sear and trigger.

At this point I will back off. Exactly how all of this is done is usually closely held by the ‘smiths who earn a living doing it.

In the meantime, don’t let the revolver, and/or parts rust. Spray everything down with corrosion resistant oil, and later remove it if you want with a bath in mineral sprites.

 

[mikemyers]

Will do.

When my friend Art bought the gun in the 1980's, he only used it for a very short time, then put it away. I got it from him, and didn't start shooting it on a regular basis until a few months ago. This thread got started, because the trigger pull was very erratic, which made it difficult to pull the trigger smoothly. The suggestions here were to clean it, but being very nervous about opening up the gun, I hesitated. Fast forward to my trip to Fellsmere, where I met Will at Sebastian Ammo - I was there to buy ammo. We all got to talking about guns, then my gun, and Will showed me a gun he had re-worked. With me thinking all my gun needed was a good cleaning, we agreed I would bring it back a few days later, and he'd clean it.

That's how all this started, and Will took the gun apart, sprayed it, wiped away a small bit of surface rust in a few places, and tried to install the Wilsoncombat performance spring kit. We didn't think the mainspring in the kit was right, so we gave up on that. Will put in the original 18# return spring, and the trigger got "stuck" while being released. Will cut a coil off the 18# spring, but nothing changed. Eventually Will noticed that by tightening up the screw that tightens the main spring, the gun got better.

He put the gun together finally with the Wilson 12# spring, and while the gun was had a smoother trigger pull than when I brought it in, the trigger still got "stuck" on something as it was returning. Before Will did any of this, I only had enough strength to pull the trigger in DA mode by using the joint in my trigger finger. After Will worked on the gun, I could pull the trigger using the fleshy part of my finger. I am now guessing that this is because of the 12# return spring, rather than the 18# spring.

Before Will worked on the gun, I never noticed the trigger getting "stuck" while it was returning (but I never knew to even look for this back then). After Will worked on the gun, I'm very aware of it.

When the spring tool arrives from Brownells, I will re-assemble the gun using the stock 18# spring that Malamute sent me. Brownells is also sending me a spring kit, which maybe I'll get to try later. I don't know what, if anything, I can do after that, other than send it to S&W or find a gunsmith I trust.



If Dykem is available at a local shop, I'll buy some. If not, I'll order it. I'd like to see what part of the trigger gets "worn" as the trigger pushes against the cylinder stop. (You guys can't see this, as you're not here. I don't know how to show it in a photo, or in a video. I think the cylinder stop moves freely, but unless I remove the cylinder stop, I can't see the surface that the trigger slides over. What I can see, is that as the trigger is moving forwards, it meets the cylinder stop, and as the cylinder stop is pushed forward, the trigger returns. If this is supposed to be a smooth movement, it isn't - it feels rough to me. Finally, JUST before the trigger moves up over the notch in the cylinder stop, the trigger gets stuck. It takes more and more pressure, and then it suddenly moves over the edge, and all the pieces go back to their normal position. Bottom line, what I can "see" happening with the side plate off, and what I "feel" as I'm doing this, seems to me to be exactly what I felt when the gun was assembled, and the trigger was getting "stuck" before moving forward. (On my trigger, that sharp surface that is rubbing along the cylinder stop, is very different from the nicely smoothed surfaces I see in all the photos I look at online of other similar revolvers.)

It sure does seem to me that the trigger should move forward, contact the cylinder stop, which will be pushed forward so the trigger can smoothly move upwards until it passes the notch, at which point the cylinder stop spring will push it rearwards.


Anyway, I guess I'm pretty much done for a week until the parts arrive. I've never removed a cylinder stop, and Will was reluctant to do it, although he finally did it anyway. Is this something I should be taking off??


I got a response from Wilsoncombat about their spring kit - I'll copy their email here, as others might be puzzled by how different the Wilsoncombat kit mainspring looks:

Anthony (Wilson Combat Support)
Jul 14 20:36
Mike,
I just heard back from the spring vendor and the springs we are getting are correct and we measured ours to prints. Even though they are a different shape (and shorter) when out of the package than a stock spring they will work fine in your Smith that is how they are designed to be somewhat lighter and smoother in operation than the stock spring.
Sincerely,
Anthony
Online Technical Support
1-800-955-4856
Fax: 1-870-545-3310
www.wilsoncombat.com​

 

[MrBorland]

As usual, Old Fuff makes a good point - the S&W DA trigger pull is actually a 2-stage setup, and smooth mating surfaces and especially a smooth transition from the trigger nose to the cam is important (check out my earlier pic for the labeling). No argument here.

However, I'll point out that ol' Larry didn't address this transition. He just put a little shine on the DA sear and leading edge of the trigger nose, and suggested that's enough to smooth & lighten up an action. Maybe it was enough in this particular case, but it's likely most revolvers would also require attention to the many other interactions involved in the pull (and release) to get a smooth action, which is what my point was.

 

[Old Fuff]

Unfortunately the video shows more then is explained.

Which is the reason I went into such detail to point out how the system works. This is something the video didn't do, and exclusively focusing on the sear would be a mistake, although an incorrectly fitted sear is a common cause of double-action issues. As a general rule-of-thumb a professional action job usually includes a new sear, and again that's something you seldom see mentioned on the Internet.

That said, it's not my intention to write a complete manual and post it on this thread. What I have posted is mainly to keep mikemyers from doing something he'd regret later.

 

[mikemyers]

I think one issue is now identified, and hopefully fixed.

I slid what little is left of my fingernail along both the cylinder lock, and the projection on the trigger that hits the cylinder lock as it moves forwards. Both had an annoying "burr" that I couldn't see, but could easily feel. Since my camera "sees" better than my fingers, i eventually managed to get a good photo of each:



I understand what you guys are saying about not doing anything to the gun parts unless I'm sure it is the right thing to do - but there is no way that "burr" or whatever it is, should be there. I called Will at the gunshop, and he has a replacement cylinder-lock in stock, so I can always replace that if need be.

I rubbed the sharp edge (with the "burr") at end of the projection from the trigger against a fine stone for about ten seconds, then cleaned it with scotch-brite. I can't see any visible changes, but the "burr" was just about gone. I thought ten seconds more, and it would be better, but I left it as-is for now.

As for the cylinder-stop, since I'm not sure about removing it (maybe I can learn later), and I didn't want to change anything, I simply rubbed the end of a good sharp screwdriver over it for 30 seconds or so. After doing this, it passed the "finger test". (When I look at it in the photo above, to me it looks like a "notch" that was catching the trigger, preventing it from smoothly sliding over that last bit of travel.)

I put the trigger back in the gun, and it was about 90% better. There was just the smallest hint of it "locking up" against the cylinder lock. Not wanting to do more to any of the parts, I just sat there, moving the trigger back and forth for five minutes. At that point it was almost perfect. So, I did this for another 5 minutes, and now it's quite smooth - no binding.

Unless you guys tell me otherwise, I think this part of the repair is done. All I need to do (hopefully) is re-assemble the gun using the stock springs. I can always try lighter springs later.



If it wasn't for me following all the advice here about waiting for the spring tool before re-assembly, one of two things would now be true. Either the gun would be all assembled again, and I'd be ready to go to the range tomorrow, or I'd be searching all over my carpet for a missing spring....


(Considering how long this discussion has gotten, I hope you're all not too annoyed at me.... and I *very* much appreciate all the help!!!! )

 

[Malamute]

Sounds like you're well on the way to getting it working well.

Regarding the spring tool, I have no doubt they make it easier to install the spring/rebound slide, but I've never used one (or seen one) and never launched a spring or had much trouble installing rebound slides. Push the spring into the slide enough to get it caught on the stud, then readjust the screwdriver to get it squared up and all the way on. Sometimes it goes smoothly right off without the second step, but it goes either way.

Don't be shy about the cylinder lock bolt. Go slow and watch how the spring functions. Older guns had a screw that held the spring in. Pushing the spring down with a small screw driver may help free it up. The spring can move sideway a little and let the bolt come free if done carefully.

The lock bolt looks fairly rough, as do many other parts. If it were me, I'd carefully polish them, it doesn't take much to get improvement. The burr is a problem though.

If you are careful and good with your hands, you can hand polish parts. I use 320, then 400, then 600 wet or dry paper on a piece of glass, and a Brownells small triangular ceramic file. If you vary the angle slightly each time you work the part, you can see the way the work is going, not as clearly as with dykem, but it shows a different polish mark when changing direction. Its one way I keep the work flat and where I need it.

The ceramic files get loaded up with metal. Use a touch of dish soap and warm water and rub it off, they clean up nicely.

 

[mikemyers]

Thanks.... I don't even have a tracking number yet for the tool I ordered from Brownells. Since you sent me four springs, the worst that can happen is the spring goes airborne and gets eaten up by my room, but with the pointed tool suggested in the following post from BCRider in a different thread, this doesn't seem likely, and even if the spring got lost, I'd have three more.

.......The rebound block spring does have a tendency to want to leap away when replacing it. I found that a simple 1/4 inch wide thin screwdriver if ground so it's got a "V" point on the nose makes a great tool for putting the spring and block back into place. Grind the tip so the point of the V is in the middle and the angle between the sides is fairly open at around 120 to 130 degrees. You want the point to center in the spring but not hold firmly when you push the block back down over the spring retention pin.......

If I'm going to try this, I might as well start with a Phillips screwdriver, with two of the blades ground off.


I also noticed I had a small pin inside my rebound spring when Will first took apart my gun. I assumed that was a normal part of the revolver - but I notice it doesn't appear in any of the photos and disassembly/re-assembly articles I've been looking at - I tried searching for information, and the only thing I found was an old post by "Old Fuff" dated back in 2003. I guess I can leave it out for now, and put it back in once I figure out which set of springs is going to stay in the gun...

Old Fuff
October 23, 2003, 07:11 PM
.....the purpose of that pin inside the rebound slide is to act as a trigger stop, but they are seldom adjusted close enough too do any good. I think they were used more in "N" frame guns then anywhere else. Post-war "KT" (Target) frames had a built-in stop in the frame. However these were often removed from target-grade combat guns (models 15, 19, etc.).If the pin is carefully fitted it makes an effective trigger stop, and eliminates any backlash after the trigger releases the hammer. On double-action-only guns it can shorten the trigger's travel and prevent the back of trigger from pinching the trigger finger against the trigger guard.If it works like it's supposed to I'd leave it in. If it doesn't and you remove it nothing consequential will happen.

 

[MrBorland]

You could work with everything inside a shoebox, or even a clear ziplock bag, so if the rebound spring does launch, you won't lose it.

Yep - that pin sticking out of the rebound slide is a trigger stop. It might be fitted well enough to do something, but it might not. You can put it in or leave it out for now.

 

[mikemyers]

Wow.... I don't know how to ever thank you guys enough for all your help, and for even putting up with someone as ignorant about this as me.

Gun is all assembled with stock rebound spring, and everything is smooth as melted butter. It felt "lumpy" as I pulled the trigger back (hard to describe), but one additional half turn of the screw that tensions the main spring, and it felt great. I tightened it another half-turn, just in case, and right now the gun feels as good as any revolverI've ever tried!

The Phillips screwdriver worked flawlessly, as the spring never had a chance to go flying, but even if it had escaped, I had everything surrounded by enough fingers that it couldn't go far. The spring went in far enough for the slide to pull down most of the way over the pin, and with a small flatblade screwdriver, I was able to push it in just that little bit further so the slide went back in place.

With the cylinder lock interface smoothed up so the "burr" was gone, there is no longer any trace of anything getting stuck. The gun feels as good as ever in SA mode, and for the first time ever, it feels like the other S&W revolvers I've used in DA - I can't tell the difference between the way this gun feels now, and the two "Pro Shop" S&W guns I checked out at Will's shop, other than that they have a lighter pull in DA mode (....that's my ability - I suspect that many of you would instantly feel the difference, knowing what to check for).

Very happy right now!!

Thank you all!!

 

[Old Fuff]

Boy...! It's going to take more then "a book" to get you straightened out.

This time the lesson concerns the mainspring screw. It should always be screwed all of the way in and tight. It was never met to be used to adjust mainspring tension. With the sideplate assembled and screwed down tight, back out the mainspring screw and notice that the mainspring (which was bowed) is getting straighter. As it does the hammer's cocking stroke (in either single or double-action) will start to feel very different, and if the spring gets too straight you can't move the hammer at all.

At best you'll get light hits, and at worst a broken mainspring. Also if the screw isn't tight it can work itself loose, with consequences you likely don't want to think about. If you believe that the spring tension is too much (unlikely in a general purpose revolver) a thinner/lighter spring is the correct answer.

 

[mikemyers]

Now you've got me somewhat confusabobbled.....

In Jerry Miculek's video (https://www.youtube.com/watch?v=H9gn7zE5b3g) he is using the mainspring tension to set the strength he wants (he measures the trigger pull with a gauge, and then modifies the length of that screw to provide the desired trigger pull - at least I think that's what he is saying.

I'll remove the grips, and tighten the screw down all the way...

It's not going to be a general purpose revolver, it's only going to be used for making holes in paper, hopefully with the holes being close to each other so none of them get lonely....

 

[mikemyers]

Follow-up.... it took just a bit over 1/4 turn to bottom out the screw. The trigger pull feels identical to before I did this.

Is the reason you want that screw to be all the way in, to prevent it from backing out, or is the spring tension of the main spring designed to be correct when that screw is fully tightened? ....or both.

 

[MrBorland]

I don't know if there are better reasons based on design, but that strain screw won't stay put (even with Loktite) unless you've got it screwed all the way in. Save yourself some future headache, and keep it screwed down. And don't cheat, and file it down, either (something else the interweb night tempt you to so).

As with a number of revolver-related issues, just 'cuz Jerry does it doesn't make it the only way, the best way, or even right.

 

[Old Fuff]

Well I tried to explain what can happen if the screw is able to get loosened too far. When your shop manual arrives you should be able to learn more.

Jerry Miculek can feel the slightest change that may occur in one of his revolvers, and quickly corrects whatever may need correcting. Not everyone else has trigger fingers that are trained to the same level. By the way he offers his own mainspring/rebound spring kit for competition revolvers only. (See at Brownells).

The main reason for the fully tightened screw is that if it isn't tight it will move itself without notice.

Incidentally, Smith and Wesson is no longer supplying mainspring strain screws for square-butt N frames, something that a whole lot of folks with shortened screws have discovered to their sorrow.

 

[mikemyers]

.........As with a number of revolver-related issues, just 'cuz Jerry does it doesn't make it the only way, the best way, or even right.

Just like with anything else, it's really difficult finding out who to listen to, whether it's in conversation, written words, or YouTube. The more you know about something, the more you find fault with what others say. Then too, the people who REALLY know things the best, aren't always the same person who wants to type all that stuff into a web forum.

I go to lots of forums, and even run/ran my own. Most of the verbiage is pretty meaningless, but thanks to several of you, THR is a goldmine of excellent advice and information.


Me? I'm just learning - I know FAR more about photography than the things I take the photos of. Since I don't know what to look for, things sometimes jump out at me when I see them enlarged as if I was using a microscope!



Maybe I can pass on a suggestion to others. Years ago, when I was doing a lot of mechanical work on model railroad equipment, I bought a couple of these "trays" from my local hobby shop. They're plastic, and have curved edges at the bottom of each compartment, to make it effortless to slide out a tiny part (such as screws, or whatever). Here's a photo I took:

This is 30 years old, so the same people may no longer be selling them, but the stick-on label says "Ernst Mfg. Inc., #159 Deluxe Hobby Storage Tray". They were/are in Sandy, Oregon.

It's a great way to keep bits and pieces all organized, especially for people who may have more than one gun disassembled at a time.

 

[MrBorland]

Well, I'll pre-empt the following by giving you kudos for asking questions and doing some research...

...that said, in addition to being a bona fide top notch competitive shooter, Jerry's developed himself over the years as his own brand, and as a guy how has to make a living shooting, he's not above marketing that brand with little internet exhibitions and little vignettes on how to shoot.

I include his shooting tips as "marketing" because they're generally very basic and perfunctory. He's not in the business of making you a better shooter or a revolver tuner - he's in the business of earning a living. Compare his internet tips with some of the really excellent and highly detailed books by Brian Enos, Ben Steoger, Mike Seeklander, and others, and you'll see what I mean. It seems to work well for him and his brand, because when Jerry says or does it, it's gospel.

None of this should be construed as trying to take anything from his extraordinary skill, and I have the utmost respect for him as a revolver shooter. But I've learned almost nothing about revolvers (shooting or tuning) from him (and yes, I've got all his DVDs), which is ok because I and many other competitive revolver shooters understand that, unlike us, he's actually gotta make a living with his revolver. <rant off>

Cool organization rack, BTW. Clean work area, too.

 

[mikemyers]

Understood - I've got a lot of catching up to do, and apparently a lot of reading to do as well.... starting with the S&W book which gets delivered tomorrow, not today... :-(


Here's the simple tool I made to prod the spring back into the slide. It started out as a 0.2" diameter Phillips screwdriver, and I ground off the "top" and "bottom" blade, leaving only the side blades to rest against the spring. The tip protrudes into the spring, so it's trapped, and the tool is forced to be right in the middle of the spring because of where the blades hit the spring, they force the blade into that position.

Any credit for this should go to BCRider, not me, as his idea is what got me thinking about a way to make it even better.




It's extremely easy to use, and the spring never even hinted that it was looking to go airborne!!