I replaced the mainspring in my 686-6 with a new factory, standard power mainspring and now the action is noticeably stiffer. I'm wondering if there is a break in period where flexing the spring a bunch of times will soften it up a bit or do I shave some off the strain screw to even out the pressure. I compared my strain screw with a new one and the length is the same. Any help would be really appreciated.

Do Not shave the strain screw. The main spring can be bent to ease the trigger pull or get a redused power main spring.

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Make certain the mainspring is properly seated; dry fire; go to the range. Then see if it's still an issue.

Suggest you don't shave the strain screw or bend the mainspring.

If it continues to be an issue, return it for another factory mainspring, and consider one from Wolff, too.

Each individual gun, even within the same series, has certain unique variables with how it responds to -- you guessed it -- each individual mainspring, even within the same design.

Sometimes you have to experiment with a few until you get the right feel and reliable ignition.

Ok, yeah when I took the old mainspring out it had a bend to it and the new one was almost totally straight except the end curved over near the hooks. I was wondering if the spring was bent before installation or it just broke in over time and got that bend which will happen to the new too? Also, I was watching the American Gunsmith Institute video on Smith revolvers and he said he liked the spring pretty straight, he even took one out of a gun and hammered it down to make it straighter before he installed it back into the gun. So I don't know what to think.

YOU CAN TAKE SOME OFF THE S,SCREW.IF IT IS A NEW SCREW.

I don't like to bend Main Springs. I rather take a little off the strain screw. The strain screws are inexpensive and very easy to work on. After working on then for a while you will get the feel of just how much to take off. If you go to far, throw it out and start over with a new one - they are cheap! Get a few to have on hand. If you ever want to return to Factory Spec's simply install a new screw.

Once you bend a main spring you really can't go back to Factory Spec's, and you are really just blindly guessing.

Just my .02 cents..........

Chief38

That's what I thought too, but I thought it was interesting that the old spring did have a bend to it. Do you think the factory bent the spring before installing it? Or did it get that bend from being used. Also just to check, I took the mainspring out of another new 686 and it had a bend to it too, so I am confused as to how the springs are getting these bends in them when the new one I ordered was much more straight.

I put a Wolff standard power ribbed mainspring in my 686 about 20 years ago along with a 13ib trigger return spring. Smoothed out the trigger pull and lightened it enough that more than one shooter has asked me who did the action job.

Recently started getting misfires (I was using rifle primers to set off Mulwex AR2205 (the replacement for Hogdon H4227 powder which I used to use exclusively in .38 special). When I got a new ribbed mainspring and trigger return spring for my S&W Victory model I made sure I bout a 3 spring pack and replaced the now 20+ year old one in the 686 again too.

Worked great.

I have to agree with this advice. However with a background as a Machinist/Engineer I like to make up shims to fit under the head of the strain screw so I can "tune" the action to the exact DA trigger weight I have found to function reliably with every primer brand made as long as it is fully seated. BTW, that is 9.0 lbs. and it's reliable with CCI Magnum and even Remington Magnum primers. Typically with a brand new S&W shims between 0.020 and 0.030 inch are all that is required to reduce the factory DA pull in the 12.5 lbs. range to 9.0 lbs. I'll also note that I've found the "ideal" rebound spring is the 14 lbs. weight, it gives a good rapid rest and produces a single action trigger just over 3 lbs. in a well broken in revolver.

A properly heat treated spring can be bent and will stay where you put it. S&W factory springs are very good quality. They don't bend on their own just from use. If you want a bend in it, you have to put it there. I have spring tuning down to a fine science, but it isn't something that is easily explained in words.

Everyone has their own ideas about what is right and wrong, especially when it comes to revolvers. Some say don't do the things that work very well for me. In the end, I think everyone has to evaluate the information presented and decide what is best for their particular situation.

I'm running reliable 6 lb. DA on my competition guns, but more like 12 lb. DA on carry guns. There is more to it than just tuning the gun to get a reliable 6 lb. action. A lot of details in both gun and ammo must be accounted for.

I have only worked with a couple of main springs in the last year or so, but those appeared to be thicker and stronger than those of old.

Perhaps they are making them stronger to overcome the misfires that that have continually been reported here on new guns. Perhaps they were anomalies. The double action pull on those guns were off the charts!

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Richard Gillespie
FBINA 102

I purchased a parts box at an auction a couple years ago. There were quite a few S&W parts, including about a dozen mainsprings. I was amazed by the difference in the basic factory spring, both in thickness and width. I assume they purchase fro a variety of jobbers and the specs vary from batch to batch.

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H Richard
SWCA1967 SWHF244

Yes - the factory springs do vary quite a bit from one to another.