Revolver Main spring modifications???

[Marke]

:Hi
I was wondering if you grind down either side of the mainspring in the revolver, do you get a lighter trigger for double action or would the tension/pressure that was in the spring be minimised to a lesser tension, in other words no good to reduce the double action? Or can it mess up the workings of the revolver, in this case the 929?

I do have spare mainsprings I have bought for previous guns over the years and I would be using them and not the original.
Also if you have about 8 lbs for double action is it advisable to try to get the weight down any lower, say to 6 lbs????

I have polished the inner workings of the 929 so it is has a smooth action and is great to use but I would like to make the double action a bit lighter??? I have put in an 11 lb trigger return spring to help in the double action weight.

Any help would be much appreciated.

John

 

[OKFC05]

For my IDPA revolver, I use a 14# return spring and a strutted mainspring with the strain screw set to 7# double action in a Model 66. It fires my handloads with Federal primers 100%, but may not fire other primers.
I much prefer the strutted reduced mainsprings to anything I have seen done to the stock spring. They are cheap and easy to change back to stock if you want to sell.


I have a 686 I used in IDPA for awhile and returned to 10# trigger for a walking around gun in the field. It will fire any commercial ammunition 100%.

 

[chief38]

The ONLY time I've ever taken material off the sides of a Main Spring was on a pair of my Colt SAA Revolvers that I used in SASS / CAS Matches where speed was quite important. I did not grind down the originals (bought another set to grind) and have since replaced the ground down versions with the Factory ones since I no longer shoot SASS matches.

I do not recommend doing that to a Smith and Wesson or other revolver unless it is a single purpose firearm that is not used for self defense, home defense, or anything other than a "shooting game" where your life would not depend on the firearm. Ground down Main Springs are more susceptible to fatigue and breakage but in my case I was lucky and that never happened. If a Revolver goes down during a match the only consequence you would suffer would be to your score and your pride. I would NOT trust my life on a ground down spring.

 

[dfariswheel]

As above, grinding S&W mainsprings can cause stress risers that can cause the spring to just snap unexpectedly.

These days there's no reason to grind springs when companies like Brownell's sell a number of brands and types of new, lighter springs that you simply replace the original spring with.

 

[Protocall_Design]

As mentioned above, the lighter action thing is ONLY for target shooting and competition guns, NOT for self defense or duty guns.
With that said, you can put a large radius bend in the middle of the spring to make it lighter.

To take it another step, you can use a #8-32 x 1/2" long socket set screw with blue Loctite on it for the strain screw so you can adjust the spring tension and experiment to see what works the best. The Blue Loctite allows you to make adjustments with just the allen wrench and not heat. Don't use Red or Green, it will be locked up solid. This also works well with the Power Rib springs made by Wolff Spring.

 

[Marke]

thanks for that I will leave the mainspring as is.
I did read that some have put a rounder bend in the mainspring and I was wondering how that makes a difference? Does it add more strength to the mainspring or what??

 

[Protocall_Design]

thanks for that I will leave the mainspring as is.
I did read that some have put a rounder bend in the mainspring and I was wondering how that makes a difference? Does it add more strength to the mainspring or what??

The main thing it does is get the top of the mainspring lower, effectively shortening it a little bit. The closer you can get the stirrup on the hammer parallel to the rebound slide, the less downward pressure is on the r/s at a given m/s tension. Then it takes a lighter rebound spring to reset the trigger and rebound the hammer.

To take it further, you can curve the bottom of the m/s forward, and the upper middle backward. The m/s is then in a slight S shape. Done correctly, that gets the stirrup horizontal instead of the 45 degree upward angle that it normally is. All this m/s tweaking requires an adjustable strain screw in order to tune the spring to it's optimal performance.

All my carry guns are full strength factory. All my match guns are in the 6 - 6.5 lb. DA, except for 2, which are lighter. The match guns are 100% with firmly seated Federal primers. That takes care of light. For smooth, you have to go through and fit all the moving parts to work in perfect harmony. The lighter the trigger pull, the more you can feel if something is off a little.

 

[chief38]

As above, grinding S&W mainsprings can cause stress risers that can cause the spring to just snap unexpectedly.

These days there's no reason to grind springs when companies like Brownell's sell a number of brands and types of new, lighter springs that you simply replace the original spring with.

I ONLY did it for SASS Matches (on my two Colt SAA's) and AWLAYS carried a spare and screwdrivers if one broke during a shoot. I would NEVER recommend it on a Revolver one's life may depend on. Luckily, they never failed and sill have the Springs in my parts box. At the time, 30+ years ago, there were no lighter springs available for SAA's.

 

[cmj8591]

Most of us who have been tinkering with Smith revolvers for years, at one time or another, have done all sorts of unspeakable things to the springs in an attempt to make the gun fire with just brain waves. Some fixes work better than others. I've found that installing Wolff springs seem to be the best compromise between function and reliability. If you go to their web site, you will find all sorts of combinations of main springs and rebound springs for just about every application.

 

[Protocall_Design]

For most people, you are probably right about just getting the Wolff springs. Some of us dedicated gun plumbers like to get the Nth degree of performance. Thankfully, I have a lot of spare parts to experiment with. I have tried every conceivable thing to get a lighter DA pull. I only share those few things that have actually worked, with the forum, for like minded individuals. Who knows - maybe someday someone will come up with a new innovation to go to the next level...

 

[cmj8591]

Who knows - maybe someday someone will come up with a new innovation to go to the next level...

And we will still tinker around trying to make it better until the the gun ends up a steaming pile of unrecognizable parts!

 

[Protocall_Design]

Ha ha. Yes we will!

 

[perryhd]

We work on them until they will not shoot then we start over.

 

[625-7]

As cabin fever sets in

and I just received my new S&W screwdriver bits from Brownells mebby I'll give the 66 a clean up and tune up! So the trouble begins...

 

[stu1ritter]

If you play with springs then hammer lift weights (how many ounces does it take to cock the hammer) are your friend. By setting hammer lift weights just above minimums you will be able to ignite almost everything. This has been discussed here before and armorer951 spells it out in post #3 of this; way to check hammer forcewhen falling


Stu

 

[Protocall_Design]

That's how I do it, only I use a trigger pull gage. Then instead of checking for one weight, you can measure what it is and adjust it for what you want. If you record the setting that works for that gun and your ammo, then you change springs or want to experiment, you can easily go back to that setting. By using a headless setscrew and blue Loctite you can adjust the mainspring to whatever you want it to be, regardless of the type of mainspring.

 

[stu1ritter]

Thanks tool guy, I like the headless set screw technique and think I'll start using it. I usually grind the screw down to what I need, polish the end and tighten them up. Sticking to S&W's listed weights I've never had a misfire.

Stu

 

[old&slow]

Some fixes work better than others. I've found that installing Wolff springs seem to be the best compromise between function and reliability. If you go to their web site, you will find all sorts of combinations of main springs and rebound springs for just about every application.

+1 . I find just buying a Wolff spring kit is much easier.

With several stock S&W main springs laying around, I have played with rounding edges ,, shaving them down a little ,, etc.. which is interesting. But, just ordering a spring kit takes less time and is much easier..

Plus if it doesn't work right ,, you always have the stock springs..