stiff single action trigger on S&W 686

[e rex]

Many years ago I sent my "then new" 686 to S&W and ask if they could help on old man out with the trigger pull. They changed the trigger return spring ( I don't recall what they put in) but a couple of years ago when I started getting light hammer strikes I discovered that they had ground the end of the strain screw and it had worn too short over the years. I ordered a new strain screw and the light strikes went away but I'd like the single action pull just a bit lighter. What do you fellows do? I hate to back the screw out and lock tight it, also am leary of grinding the strain screw. Do I gut it up and grind the screw or back it out a bit and glue it in place?

 

[nick22]

I have not had very reliable double action reliability unless the strain screw is all the way in. If it starts feeling almost too good I check it. I also wouldn't grind the strain screw I believe a lighter return spring would be of help but only during double action, I've never had a Smith revolver that had a bad single action trigger break.

 

[halfmoonclip]

Okay, first, did Smith indeed shorten the strain screw? Compare the two.
Likely your mainspring simply took a set, leading to the light strikes.
You can simply replace the mainspring, either with a factory one, or a Wolff ribbed mainspring (use the full powered version). With the ribbed mainspring, it may well give you a good trigger with the full length strain screw.
The rebound slide spring also affects trigger effort, but it won't cause misfires. Too light a rebound spring can give you sluggish trigger return.
Stay in touch; I'll be happy to talk you thru' any questions.
Moon

 

[e rex]

Thank you fellows, yes the strain screw was shortened. By the time I figured this out it had worn down to almost the screw threads themselves. I'll try a lighter rebound spring and see what happens. Thanks again.
Rex

 

[derek45]

Okay, first, did Smith indeed shorten the strain screw? Compare the two.
Likely your mainspring simply took a set, leading to the light strikes.
You can simply replace the mainspring, either with a factory one, or a Wolff ribbed mainspring (use the full powered version). With the ribbed mainspring, it may well give you a good trigger with the full length strain screw.
The rebound slide spring also affects trigger effort, but it won't cause misfires. Too light a rebound spring can give you sluggish trigger return.
Stay in touch; I'll be happy to talk you thru' any questions.
Moon

exactly this.

I am surprised S&W shortened the screw, I suspect all the revolver smiths have long since retired from S&W

Jerry has a good DVD on tuning up the S&W revolvers.

https://www.midwayusa.com/product/1014247174

 

[halfmoonclip]

The strain screw was worn down to its thread? I think that unlikely, nor would the factory have shortened it that much.
Make sure we're clear on terminology. The mainspring is the long, flat spring in the gun's butt. The rebound slide spring is the coil spring within the square rebound slide itself.
Which spring are you considering replacing?
(Curious; how did you remove the sideplate?)
Moon

 

[MrBorland]

Leave the strain screw tightened down all the way. Putting in a lighter rebound spring will lighten the SA pull weight. As noted, depending how light you go, you might have issues with the trigger fully returning, particularly noticeable when shooting in DA mode. Ideally, the main & rebound springs will be properly tuned to work together.

Someone also mentioned the side plate: if you don’t already know, there’s a right way and a wrong way to open a S&W revolver. Take tension off the mainspring before removing the side plate, and don’t pry the side plate off.

 

[Riomouse911]

There are several good tutorials on you tube that give a complete how-to guide on S&W revolver innards. Watch one or two to get the feel then follow along. It is best to start with a good set of gunsmithing screwdrivers like the hollow-ground sets from Brownells, Wheeler, etc. These won’t strip or bugger your small screws like a regular set of screwdrivers will.



I use a Wolff reduced power mainspring and rebound springs in my S&W’s, and I use 1000 grit wet-dry sandpaper with a flat backer to polish off imperfections on all sides the rebound slide so it glides like its on glass. I will also lightly touch the interfaces of the trigger and sear with 1500 grit just to smooth any small imperfections. This I do very sparingly, as I don’t want to alter angles or round off edges that need to be there for safe operation.

To replace the rebound spring, I recommend that you find a beat up old screwdriver and grind it in a shape like this one (Courtesy of Bob Chavez, Gunsmithing Instructor at Lassen Community College in Susanville, Ca. He gave it to me at a S&W Armorers course he taught).



This simple tool makes the removal and installation super easy. (Be careful around the fixed pin that you have to put the rebound spring over and past. If you break the pin thats not good at all for your S&W!)

Its not rocket science, just takes patience, the right tools, the right springs and a bit of tutoring via you tube to get it right.

Good luck, and stay safe.

 

[trackskippy]

Okay, first, did Smith indeed shorten the strain screw? Compare the two.
Likely your mainspring simply took a set, leading to the light strikes.
You can simply replace the mainspring, either with a factory one, or a Wolff ribbed mainspring (use the full powered version). With the ribbed mainspring, it may well give you a good trigger with the full length strain screw.
The rebound slide spring also affects trigger effort, but it won't cause misfires. Too light a rebound spring can give you sluggish trigger return.
Stay in touch; I'll be happy to talk you thru' any questions.
Moon

Just an FYI with the Wolff mainsprings if you should swap on for the factory. They work fine, and I have no complaints there, but they can and do have an issue because of that "rib".

Ive swapped a number of springs with them now, and the "rib" comes down far enough on the spring, that the strain screw lands in it. With the factory springs, its "flat" at the point that the screw hits the spring, and not a problem. With the rib, it makes the screw a tad short, and you dont get enough pressure on the spring.

I was getting light strikes and was wondering what was up, as the spring was supposed to be full power. Once I figured out what was going on, I put a spent primer on the tip of the strain screw, which acted as a shim/bridge, and it solved that problem.

I dont know if the placement of that rib is supercritical or not, but Wolff needs to just move it up a skosh, so the screw doesnt land in it. Either that, or youre likely going to have to replace the strain screw with something longer than the factory screw, or jury rig it with something like the primer.

 

[Jim Watson]

I have seen that with the Power Rib spring, too. I have at least one gun with primer cup shim, maybe two; it has been a while since I had the grips off my K38 to look.
Teddy Jacobson had a strain screw made out of a long set screw with the tip ground into a pyramid. It would click stop by the quarter turn with that pyramid in the groove.

Should I want to diddle another S&W spring set, I have a Wilson on the shelf. I think I could find Skeeter Sketlton's "buggy whip" grind, too.

All my attention has been toward the double action, I have never seen a S&W Hand Ejector with what I would call a heavy single action, more with hair triggers.

 

[trackskippy]

Same here. I shoot DAO and always thought the SA triggers were a bit too light. Always thought the factory DA triggers were just about right.

 

[Riomouse911]

I have seen that with the Power Rib spring, too. I have at least one gun with primer cup shim, maybe two; it has been a while since I had the grips off my K38 to look.
Teddy Jacobson had a strain screw made out of a long set screw with the tip ground into a pyramid. It would click stop by the quarter turn with that pyramid in the groove.

Should I want to diddle another S&W spring set, I have a Wilson on the shelf. I think I could find Skeeter Sketlton's "buggy whip" grind, too.

All my attention has been toward the double action, I have never seen a S&W Hand Ejector with what I would call a heavy single action, more with hair triggers.

It is amazing how adding that thin piece of metal to the tip of the screw adds enough pressure to the mainspring to improve hammer impact on the primers. I have also used that trick (I find LPP worked well) on S&W guns that have a light-strike issue.

Best part about these guns is fixing an issue like light strikes is not tough to do.

Stay safe.

 

[halfmoonclip]

I have a 325 that will only reliably ignite primers with a factory mainspring, and I had to use the thickest one in my spring box to make it go bang all the time. (There is some variation...)
Tried a ribbed one in that gun, great double action, but most primers wouldn't fire. It took a couple swap arounds 'till it started shooting reliably.
Moon