Installing Smith & Wesson Spring Kit
September 23, 2010
1. Remove the sideplate screws with the proper screwdriver, keeping them in order for reassembly.
While the trigger pulls on new S&W revolvers are much better than old ones, it is still possible to make improvements by simply changing a couple of springs. Several companies offer kits that include both mainsprings and rebound-slide springs for all models of S&W revolvers.
As always, proper fitting screwdrivers are the first priority.
Remove the grips and then the sideplate screws. Newer revolvers have a special screw that retains the crane, but it is fitted on older guns, so just keep the screws in order so they can go back in the same hole.
The next step is to remove the sideplate. It might seem logical to pry it off; however, that is absolutely the wrong way to do it and can damage the gun. Instead, tap gently on the frame just below the sideplate with a brass or nylon hammer, and it will pop right up and can be lifted off.
The hammer-block safety will be lying loose under it, so take care to note how it goes in. There is a small pin on the rebound slide where it rides.
The next step is to remove the mainspring. On K-, L-, and N-Frame revolvers, there is a screw at the bottom of the grip that puts tension on the mainspring. It is called the strain screw. It just needs to be loosened enough to remove the spring. J-Frame revolvers have a coil spring, and it can be removed by partly cocking the hammer and putting a punch or paper clip in the small hole you'll see in the hammer strut.
Most kits have only one mainspring--either standard or reduced power--but typically have several rebound springs of different weights. The rebound spring can have a big effect on trigger pull, so I generally use the lightest one in the kit. The downside is that the rebound also serves as the trigger return spring, and there isn't anything much more annoying than pulling the trigger and not having it come back. Try it several times before buttoning everything back up.
The best way to remove the rebound slide is to just pry it up a bit, but be aware that the spring is under considerable tension and could do real harm if it hit you in the wrong place. What I do is put my thumb over the end of the spring to catch it when it clears the stud in the frame.
Putting the new spring in can be equally tricky. There are some special tools to help with the job, but I find a flat-bladed screwdriver works as well or better. Once more, that spring can fly on you, so I keep one hand over it just in case it tries to escape.
2. Remove the special crane retaining screw.
3. Tap the frame below the sideplate to loosen it.
4. Loosen the strain screw just enough to remove the mainspring.
Here are the original mainspring and the reduced-power mainspring.
Kits come with several rebound springs.
5. Carefully remove the rebound spring to catch it when it clears the frame stud.
6. Compress the new rebound spring with the blade of a screwdriver.
7. Replace the hammer-block safety.
8. Then press the sideplate down gently, and install the sidelate screws.