S&W 340PD trigger question

[usnavymasterchief]

I own several guns both semi-autos and revos. When it comes to working on them, I don't pretend to be a gunsmith so I leave that up to the pros.
Now my question: Will changing the rebound spring in my 340PD lighten up the trigger a little without affecting reliability? I sent to Wolff's Springs for a "Shooter's Pack" of springs. I received a 13, 14 and 15 pound rebound springs and an 8 pound hammer spring. I assume a rebound spring is the trigger return spring, isn't it? I have changed a trigger return spring in a Taurus 605 I used to own, it was relatively easy and it lightened up the trigger considerably. I'm hesitant to change to a lighter hammer spring because I've read where that can lead to misfires.
Bottom line is this, there where no installation instructions with the springs that I got from Wolff and I am hesitant to crack open an expensive gun like my S&W 340PD. Will I benefit from changing these springs? Is it a difficult job? Should I leave it up to a Gunsmith? Is it worth doing? I would like to lighten up the trigger so my wife can practice with the gun, she can hardly squeeze the trigger and the gun is hammerless so no single action shooting.
Any comments pro or con will be appreciated.

 

[Old Fuff]

There is no reason you can't change the rebound slide (trigger) spring. IF YOU KNOW WHAT YOU ARE DOING. While it is not difficult to remove the sideplate and get at the rebound slide, there is a right and wrong way to go about it.

In addition the new revolvers that have MIM lockwork apparently have changes in lockwork design as well as material that may make a difference. I believe the Wolff springs were designed for the older design lockwork. This is not to say they won't work, just that I don't know.

A weaker rebound slide spring won't effect reliability so far as primer ignition is concerned, but it may effect how quickly the trigger returns and how reliably the rebound slide retracts the hammer.

I believe this subject has been discussed on earlier threads on THR. Do a search and see if something comes up.

Concerning you're wife: Of all S&W revolvers the little "J" frames are the hardest ones to get a light double-action triger pull that's still RELIABLE, although experience tells me that the older guns can still work well with a lighter rebound slide spring if the spring isn't too light.

Perhaps you should look into getting an older "K" frame revolver or a Colt Detective Special/Police Positive Special - both lend themselves to lighter double action trigger pulls then the smallest Smith & Wessons.

 

[Jim K]

The reason small revolvers don't take well to "action jobs" is that most of these lighten the mainspring (hammer spring). Reliably firing a primer requires a certain amount of hammer/firing pin momentum (mass times speed). When the hammer is small and light, a strong spring must provide higher speed to make up for the lower mass. If the spring is lightened too much, failures to fire can be experienced, especially if some hard primers are encountered or there is something else affecting hammer fall.

The rebound slide is called that because it "rebounds" the hammer to retract the hammer nose from the primer to allow the safety block to slide into place, and the gun to be opened. Its spring also serves as the trigger return spring.

But note that the manufacturer builds into the gun an extra degree of reliability to take care of adverse conditions (cold, wet, dirt, etc.). Weakening the factory springs will reduce some of that reliability, a point seldom mentioned by folks who change springs on everything just for the heck of it.

This is not just extra caution on my part; I have seen a number of "trigger jobs" by highly rated gunsmiths which resulted in failure to fire reliably. One friend bragged about the work done on his revolver by a high ticket gunsmith until he tried to clidk some bowling pins to death. We heard no more bragging from him for a long time. On a carry gun, such a failure could have an unhappy ending. That is when your heirs learn that the "lifetime warranty" meant your lifetime.

Jim

 

[Standing Wolf]

I am hesitant to crack open an expensive gun like my S&W 340PD.

Do yourself a favor. Treat yourself to a copy of Kuhnhausen's The S & W Revolver. Follow the clear, straightforward, illustrated directions.

I recently replaced the rebound slide spring in my 1951 K-22 with an 11-pound spring with superb results; replacing the main spring with a Wolff's light main spring, however, left me without sufficient hammer force to ignite all rounds.

I just did a quick check. I don't own a Smith & Wesson revolver that still has the original factory rebound slide spring.