I purchased a Wolff Reduced power spring kit for a model 686-6. Hesitant to order the kit initially due to the revolver having an 'extremely' tight fitting sideplate, making reinstalling very difficult.

Installed the mainspring and 14 lb trigger return spring several days ago. This greatly reduced the trigger pull, 5.5 lb double action and 3.1 lb single. Concerned about the possibility of light primer strikes, I ordered an extended firing pin. The pin was delivered today so I Installed it, fingers crossed that primers will ignite.

Loaded primers into empty shell casings, enough to fill the cylinder. The revolver didn't ignite any, even with a second attempt on each. If anyone has solved this issue on other revolvers I'd like to hear your fix. Otherwise, I'll go back to original spring configuration sooner than later.

Thanks all,

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5.5 on double action did you change anything else seems pretty light for that weight spring?

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Thats it, surprised me to.

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My advice, put your stock mainspring back in your 686 and throw the Wolff mainspring in the trash.

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Dave Brown
SWCA #3279

Was it a Wolfe "Power Rib" mainspring"? If it was the strain screw sits into the groove in the spring and puts very little pressure on the spring. Two solutions, either buy a longer 8x32 set screw that compensates for what is lost because of the groove, or use a cup from a fired primer on the end of the mainspring. Or, best, simply put the factory mainspring back in the gun and forget about trying so hard to reduce the trigger pull! I don't believe Wolfe addresses the issue created by the groove in the power rib mainspring, not really doing well by their customers! Maybe they expect their springs will be installed by a real gunsmith that will understand the problem instead of home hobbyists! Even simple appearing things like springs aren't always "Drop-in".

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Gunsmithing since 1961

Yes, it's the Power Rib. I will shop for a set screw locally today. For the primer cup suggestion, does the cup get placed on the end of the strain screw?

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What was the trigger weight before you made the change? Is it possible someone shortened the strain screw? How did the gun function before the new springs and hammer nose? The Wolff 14# rebound spring always works well for me, as do the RP Power rib main spring. That is a pretty light DA pull in my opinion.

Not sure of prespring replacement on double action as the trigger gauge only goes up to 8 lbs, single action was 4.1-4.2 lbs. I purchased revolver new 10+ years ago, and the strain screw hasn't been shortened. It functioned fine prior to changes, just wanted to lighten it a bit. No intention of having it too light.

I followed Alk8944 recommendation and purchased a longer set screw, I'll see how that works out this evening.

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I have found that an 8 1/2 pound D/A trigger pull will reliably ignite any primer. I have also found factory Performance Center guns with the round butt that come with the power rib main spring can have issues. A longer set screw replacing the factory strain screw solves the problem. McMaster sells set screws with thread lock.

I ran into a similar problem of too light of strikes on a 69 -- someone shortened the strain screw, didn't crank it down, and they put in too light of springs. Find a stiffer spring and make sure the strain screw is tight.

In addition to the info in post #5, the fine print on those reduced power/power rib mainsprings is that they're supposed to be used with a stock mainspring tension screw.

That being the case, are you sure yours was never shortened? Also, I've discovered that OAL on those screws seems to vary more than they used to. So, finding a set screw or maybe socket head screw as a replacement make sense.

FWIW, several years ago I tried one of those springs. I ended up going back to the/a factory mainspring and adjusted the tension screw until I had repeatable reliable ignition (over 100 continuous rounds) before trimming the screw down. Remember, the spring(s) will let down some after several hundred cycles so don't get too radical or be in too much of a hurry to fit the tension screw by trimming.

That used to be a way to alter Colts. One put a certain diameter piece of drill rod between the leaves of the V shaped hammer spring and cocked the hammer.

I've seen some strangely shaped S&W springs, but I really don't think the original can be improved on when properly tensioned.

I went with Alk8844 first solution of three suggested. A trip to home depot, purchased a 8x32 by 1/2" stainless set screw. Screwed it in enough to get decent tension on the mainspring, and checked double action trigger pull weight (7.5 - 8 lbs) and single action came in a hair under 3.5 lb.

The trigger felt great, so loaded up the primed cases and test fired. All primers ignited as intended. I will shorten the screw to remove enough material so it doesn't extend too far from the frame. See photo below.

Thanks to all for your input, greatly appreciated.

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I had the same problem with a Wolff mainspring. I called them and they sent me a longer strain screw that I could trim to size. Worked well.

Good intel, thanks

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I’ve used that same set up in a couple K frames (10&64) with no problems at all. I’ve been singing the praises of Wolf Springs for awhile. Maybe I should stop singing lol

Good to hear about your k frames. Overall, I'm pleased with the final results with the spring kit.

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In conclusion, I contacted Wolff regarding the issue. I was asked to provide the overall length of the original strain screw, which I did. The representative informed me that a slightly longer screw would be mailed to me the same day.

In the meantime, I made it to the range yesterday and successfully fired 75 magnum rounds through it. Very pleased with the results, and probably could do without the longer screw at this point but will install it when it arrives. First pic prior to shooting, 2nd after cleaning.

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In this situation, there are 3 things you can do that will help a lot.

1- Get a trigger pull gage, hook it under the hammer, pull and hold the trigger all the way back, then let the hammer/hook down on the frame, and pull until the hammer just starts to lift and take a reading. When you get it to 100% reliability by adjusting the strain screw, write down the number of ounces of hammer pull for future reference.
By using the trigger gage on the hammer, you are isolating that one item from all the variables in the rest of the mechanism, and quantifying results with numbers instead of blindly guessing.

2- Use #222 or #242 purple or blue Loctite on any strain screw. If loose, or no head like on a set screw, it will start backing out as the mainspring cycles. With these Loctites, you can adjust or remove the screw all you want with no heat, but it will not move on it's own.

3 - Once the correct setting is found by adjusting the setscrew, you can make a factory strain screw to duplicate the setscrew by repeating step 1 and shortening the factory one until you get the same reading on the trigger pull gage (on the hammer) that was recorded earlier.
After that is the time to try different rebound springs to find the lightest one that works the way you like it. Oftentimes, an 11 or 12 pound will work fine and further reduce the trigger pull weight.

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protocalldesign.com

You can expect a revolver cylinder to lock up when firing live primer only (no powder or bullets) casings. Repeat your functionality test with live ammo and see what happens.

The factory doesn't hand fit anything now. They take one of each part out of a bin of hundreds and stick it in the gun. Every part in every bin is a little plus or minus off the perfect blueprint size and geometry.

Every gun is a mosaic of all the plusses and minusses of each individual part in it, and how all the tolerances stack up or cancel out, and how they all function together as a whole. Because of this, no 2 guns are exactly alike. The MIM parts are less variable than the forged and machined parts, but still not perfect. No 2 springs are exactly alike, especially the flat ones, due to material, heat treat and bend variables.

All this is why when you're doing an action job, you have to measure what results you're getting to know what's working or not working, and where to go from there.

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protocalldesign.com

The substitute spring has a groove in it that essentially makes the strain screw shorter, not putting as much tension as it does on the solid original spring. If you do the hammer pull test, you will see the numbers.

If you get a longer strain screw or a set screw and dial the tension on the sub spring to the same tension as the original, you will get the same results in shooting the gun, because then the hammer will be hitting the firing pin with the same force.

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protocalldesign.com

I don't understand the fascination with reduced power mainsprings. The last thing I want in a firearm is something that has the potential to decrease reliability, or increase hammer fall time. There are only a couple guns in existence where the stock springs are too heavy for serviceable usage.

Not being able to inspect the gun or parts in question, all I can do is speak in general terms.

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protocalldesign.com

Always figured that engineers knew more than me so I leave all my guns the way they come from the factory.

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Old Cop
LEO (Ret.)

Ignition is dependent upon the force with which the firing pin strikes the primer

This force is cumulative , including the cumulative friction losses of the moving parts .

Weight per se is Not the most important factor in a trigger pull . Smoothness and consistency are . A smooth 12lb is much superior to a rough and inconsistent 6 lb .

Stock springs with extra slick internals are usually better than an average new ( or low milage) gun with reduced springs . Slickness of internals can come from lots of shooting , or judicious stoning .

Sufficient ummph from the trigger return spring is important for rapid DA work , and smooth functioning generally .

I'll add a small caveat to S&W Engineers knew what they're doing , and leave stock .

Occasionally by the sheer odds , tolerance stack could add up all in the wrong direction .

My amended suggestion is to keep within Factory Specifications - On most centerfire , between 8 lb to 12 lb .

I see shooter grade S&Ws just like Harleys and hot rods. Tinker, modify and make it your own. Collector grade guns, hands off. I’ve put spring kits of different manufacture in at least a dozen guns. Never a problem and never out ran it in DA. Maybe I’ve been lucky

OK Then, now I have a question;

I'm about to do my own action job on my NIB Model 686-6 6" 357. I'm gonna do the usual to clean up factory burrs and the like from the frame and trigger, hammer, cylinder stop, return spring and slide, just a Level 1 type action job (not looking for something fancy) looking for about a 10Lb DA pull, and the single action wherever it decides to land. Instead of using my Wilson Reduced power main spring (but maybe use the RP return spring), couldn't I just shorten the Factory strain screw (if needed) and still use the Factory main spring to get to my 10Lb DA pull (that's what I ran in my Smith Model 66 when I was shooting IPSC in the 70's and 80's and was very comfortable with that DA pull) ??? Right now I'm guessing I have a STOCK DA pull in the neighborhood of about 15Lbs (judging by feel of my Taurus model 66 7 shooter with a measured DA pull of 13Lbs) and not quite as smooth as my stock Taurus model 66 pull. All my equipment/tools are in storage right now so I can't be more specific on the measurements I gave for my 686, just a guess as 15Lbs DA pull, it's pretty stiff and not quite as smooth as I would like either. I'll start moving into my new place June 3 and have access to all my tools then, so sometime after that I will be doing the action job, but my question stands about shortening my strain screw instead of replacing my Factory main spring.

Unless they were over-ruled by lawyers or the board of directors after consulting the bean counters..

Takata airbag inflators are a phenominal example.

I trust Protocall Design. He knows more than most people on this forum.

I've swapped out and used the Wolf Mainspring but had to get the 8/32 set screw to make it work. It was a chore getting it to fire anything but Federal ammo.

Using the OEM Mainspring all I had to do was loosen the strain screw and then Loctite it with Blue Loctite. No problems.

McMaster has set screws with a nylon lock on them The 3/8" work well on round butt guns and the 1/2" work well on square butt guns. Round butt guns use a shorter strain screw and this exacerbates the problem of too little tension on the power rib type springs. At less than $6 for a 10 pack it's not a big investment to have both. Numbers are 95235A505 and 95235A507. This way I put the original spring and strain screw in a small zip loc bag with the gun serial number and it can be returned to stock at any time.

Thanks for the kind words, AzShooter. For those who don't know him, he is well versed on S&W revos, and a high level competitor.

I'm not the final word on anything, but I add my 2 cents to the pot in an effort to try to help others when there's a subject I have experience with. Anything I say is what I believe to be true, but YMMV. We are all learning along the way.

An easy way to lighten the trigger pull on a K, L, or N frame revo is to back off the strain screw till you get misfires with whatever ammo you want it to be reliable with, then dial it back up to 100% + 1/8 turn. If you get another misfire later on, add another 1/8 turn, etc. This is the lightest you can go with your ammo and know it will fire. NOT FOR DUTY OR CARRY GUNS.

Then with an assortment of rebound springs, find the lightest one that gives the type of trigger return you want. Some like a lighter spring for the lowest trigger pull weight, some want a snappy return for the fastest shooting. This addresses lighter pull weight. Smoothness, timing, etc. are additional. Many guns will be fine with just the spring work. Some will need other areas corrected.



The nylon lock setscrews are a good idea, but I have found that the nylon part is only good for a few adjustments, then is worn out. That's the reason I use the Loctite. It lasts for many adjustments, and you can always redo it if needed.

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protocalldesign.com

In my world every handgun is a potential self defense tool so I am mighty careful about lightening trigger pull. That's after many years of messing around with mainsprings, rebound springs, strain screws, etc.

If I couldn't get a gun to operate with a trigger pull I liked and still be 100% reliable, I got rid of it. Of course telling the buyer why I was selling it.

Gun must go bang every time, provided the ammo is good. All else is secondary.

For those looking for an aftermarket mainspring, my personal choice would be the Wilson Combat #178. Just one person's opinion, and doesn't mean there is anything wrong with the other ones. All the aftermarket mainsprings are lighter than the original S&W one, but then, that's the objective. I think the Wilson has the best geometry to give a lighter trigger pull for a given hammer tension. On the newer MIM style hammer stirrup, there may be a slight interference with the hooks on the mainspring. The back of the hooks can be filed a small amount to create some clearance if needed.

Lighter and smoother are two different attributes. Lighter feels smoother, so some people use them interchangeably, or view them as the same thing. A lighter trigger pull is normally achieved by reducing spring pressure, a smoother pull is achieved by refining the mating surface of parts that contact each other, and making the interaction of the parts more precise.

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protocalldesign.com

You were asking if there were any aftermarket springs that worked differently and/or better than the original S&W. I offered an opinion. Everyone is free to do as they wish.

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protocalldesign.com

I shot competitively for quite a while and used a Davis modified S&W Model 67 in competition. On the street, I use either factory set ups or the action work performed by Andy Horvath.

Is there a difference? Of course! But, both give me a very smooth trigger action. The Davis IS lighter, but smooth tops light every time.

The only other action work I will accept is dry firing about 10,000 times to wear the parts together.

Kevin

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Unshared knowledge is wasted.

Just as an interesting point of info... I have a 986 Pro Series 9mm revolver, that I bought in 2015 when they first came out.

It's advertised as having a Performance Center reduced power mainspring, so when I got it home, curiosity got the better of me and I removed the grips to see what a PC mainspring looked like.

Well, guess what... it looks exactly like a Wolff mainspring, rib and all.

The other thing that I immediately noticed, the strain screw from the factory was a different style from my other round butt K-Frames, but it had a familiar look... it was the longer style strain screw for a square butt frame.

On my 625-8, when I installed a Wolff reduced power mainspring, I copied what S&W did with the 986, and used a square butt strain screw... worked perfectly.

I think Wolff is doing S&W owners a disservice by not advising on their website that round butt S&W's need the longer screw.

It's an issue that appears here time and time again after someone swaps the mainspring on their round butt gun.

On square butt S&W's, I've never run into an issue substituting a Wolff spring.

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Conrad
SWCA #1830 SWHF #222

First off, I don't know beans from apple butter about anybody's spring kit--------------except for Jerry Miculek's. His is idiot proof, and will give you exactly the trigger pull you want---no fuss, no muss, and no bother-----if/when you follow the instructions. I, of course, have absolutely no need for instructions of any type from anybody to replace a couple of springs!! And when I got finished, nothing would move-----the gun was locked up tight.

Discretion being the better part of valor, I decided to start over-----after I read and understood the directions. Here's the essence of what I learned: The D.A. trigger pull will be whatever you want it to be from 7 lbs. on up. You can most certainly go lower, but you are cautioned the gun will very likely fail to fire most brands of ammo/primers except for Federal at 7 lbs. Whether that's the case, or whether I need a better trigger pull gauge remains to be seen, but I'm at 7 lbs., don't have any Federal ammo, and my WW ammo goes bang every time----every single time. And the action is as slick as greased owl doo-doo.

The design of the mainspring is such that you can dial in any amount of force you want, do a bit of measuring and cutting of the strain screw, and that's that. If/when you decide you want (or need) more force, you get a new strain screw, and start over.

Last words: Read the instructions. If/when you decide you know more than Jerry Mickulek about all this, take a cold shower, get a new strain screw, and start over.

Ralph Tremaine

It all has to do with the alignment of the stars.

I have a new hammer kit coming soon and it has two strain screws for the difference between round and square butts. They recommend a stock mainspring to get the best results with the kit.

I ordered two from Brownell;s. One I'm leaving stock and will just use the strain screw to get a 7 pound DA pull out of my 617. I'm hoping that that weight will pop off all the rounds I intend to use in my gun.

The second spring I intend to bend slightly which will give me the desired weight.

With both setups I intend to use BLUE LOCTITE to keep the screw from moving. The kit I'm getting is call the REVUP Action Hammer Kit if anyone is interested. Trigger pull is going to be different. It will get lighter as you pull through and that should add to accuracy and speed.

The only thing I can tell you about Miculek's mainspring is it has a decided bend forward about 3/8" aft of the hammer stirrup. Some of you may very well understand the whys and wherefores of that, I don't. I do know that if/when you install it, as I did the first time around without bothering with the instructions, it (the upper portion of the mainspring) is well and truly jammed against the bottom of the hammer------and NOTHING moves.

After you read and follow the instructions, and as if by magic, everything fits and works just fine.

Wonders will never cease!!

Ralph Tremaine

I find the power rib springs very consistent. The difference lies in the distance from the main spring to the front of the grip frame on square butt vs round butt guns. Also the grip frame is a bit thinner on the round butt guns so the strain screw is shorter. When I got my 627 Pro Series it had a factory power rib spring and wasn't 100% reliable in D/A. I have no idea if a previous owner shortened the strain screw but the McMaster set screw solved the issue and it now has a super smooth 8lb D/A trigger pull.

I have installed many of the Wolf spring sets with great results.

I did have a problem with one set. When installed, the trigger was terrible. Very hard and glitchy. Tried it in a number of N frames I had at the time. I was putting it in a M57 when a friend came over. Same results on the M57. He said "Try it in my M28." So I put it in. That was the best action I had ever seen with just a spring change. Beautiful. The parts were rough inside which was common for a M28. Some look perfect and some do not. It did not misfire. I gave him a set of Herrett's grips, too. He had the service grips.

It would seem I lost out on that deal but he sold me his Father's early fifties Outdoorsman with a 4.5 inch barrel for $200.00. Yes, that is a 4.5 inch.

I experimented with turning the strain screw out on various S&W revolvers. I found you could back it out only 1/4 turn with no misfires. Using the spent primer trick, I fixed a number of "trigger jobs" over the years. There are going to be slight differences in frames so test anything you do for function with the ammo you plan to use.

The cheese head screws as found on the k14, 17 etc, ( not the set screw) are made to be adjusted.
They have thread relief at the head and an extension that is not threaded so that it can be adjusted.

The space under the head allows the screw to be tightened without interference between the male and female threads. It can be turned to the same place each time.

The extension allows the screws effective length to be shortened with out messing up the threads. It also allows the screw to be shortened with out changing the thread engagement.

The mainspring is the same for both, it's the shape of the frames that makes the difference.

I borrowed this from the Altamount grip website... notice the difference in the grip frame front strap where the strain screw is at?

You can see why the square butt frame has a longer strain screw than a round butt.

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Conrad
SWCA #1830 SWHF #222

If the threads run to the head the screw can seat against the thread before the head hits the frame. Threads are actually wedges. If the screw is seating against the threads and you cut some threads off of the end the screw wont seat at the same location but on a different portion of threads..

Factory main spring screws are meant to be fully tightened.

I would like to state for the record that I know from firsthand experience that series guy knows how to set up a Smith and Wesson revolver action.


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I've been shooting a Wolf Power Rib Mainspring in my 617 for about a year and after this thead I decided to check it out. I use the McMaster's screws and mine was turned in 5 times to get my 8 pound trigger pull that made my gun work with most .22 ammo.

I ordered some shorter springs because my mainspring was just about toughing the back of the frame leaving no more adjustment.

I put a Miculek Mainspring in and to get the same weight pull I only had to screw it in 3 1/2 turns. This gives me more adjustment. With the way my gun is set up now I need that weight. I can get away with 7 pounds for Federal BYOB ammo and Golden Bullets but need the extra weight for Mini Mags and Norma Tac 22.

I've been shooting a Wolf Power Rib Mainspring in my 617 for about a year and after this thead I decided to check it out. I use the McMaster's screws and mine was turned in 5 times to get my 8 pound trigger pull that made my gun work with most .22 ammo.

I ordered some shorter springs because my mainspring was just about toughing the back of the frame leaving no more adjustment.

I put a Miculek Mainspring in and to get the same weight pull I only had to screw it in 3 1/2 turns. This gives me more adjustment. With the way my gun is set up now I need that weight. I can get away with 7 pounds for Federal BYOB ammo and Golden Bullets but need the extra weight for Mini Mags and Norma Tac 22.