Increasing S&W Revolver Single Action Pull

I have a S&W K Frame I wanted to try shooting for bullseye. I have reinstalled brand a brand new factory main spring, rebound spring, and strain screw. The trigger pull weight is still not making the minimum for bullseye. The strain screw is screwed in all the way. Most articles online are about decreasing, not increasing, the trigger pull weight. Is there any other way to do this?

Greetings,

Wolff make a variety of rebound springs.

The strain screw should be unaltered and screwed in fully.

Cheers,

Dave

The heavier rebound spring may not impact single action very much. You did not indicate what caliber you are shooting. Two to 2.5 lbs is usually easily obtainable in single action. If you are shooting .45 then the 3.5 lb bar is more challenging. 

The simple fix is the remove the main spring. It will look like a leaf spring. First, lie it on it's side and scribe the arc with a pen or pencil. This will tell you where it is now. Then, place it on hard surface with the arc up. Take your thumb and press gently down on the high spot of the arc. Then, lie on it side over the pencil mark of the arc you scribed. See it is changed. If so, put in the gun and try it. If not, repeat, pressing a tad harder. Obviously what you are doing is flattening the spring slightly. This adds tension.

Adding a little more trigger weight this way, will likely increase DA more than SA. But it will work. If you are not shooting DA, it will not matter. If the additional weight is detrimental to to your DA press, then a competent gunsmith may be needed to modify the single action shelf/hooks on trigger and hammer.

With the marks representing the arc of the hammer spring, you always put it back to the former arc. Of course using "other" main springs to modify is also an option.

How is the caliber relevant? Asking to learn, not to be snarky. Wouldn't the relationship between the geometry of the internal parts in any N frame, for example, be the same regardless of the chambering? The only different I can see is in the timing for the hand, based on how many rounds the cylinder holds. But in this case, I am working with a K frame chambered in 357 magnum. I'm not sure if I can flatten the main spring out but I can try it out.

Cd627 wrote:How is the caliber relevant? Asking to learn, not to be snarky. Wouldn't the relationship between the geometry of the internal parts in any N frame, for example, be the same regardless of the chambering? The only different I can see is in the timing for the hand, based on how many rounds the cylinder holds. But in this case, I am working with a K frame chambered in 357 magnum. I'm not sure if I can flatten the main spring out but I can try it out.

Since you said for BE, you did not say which caliber. In BE minimum trigger pull for a .22 is 2 lbs. For CF less that .45 it is 2.5 lbs, but for .45 caliber it must be at least 3.5 lbs.

You do not want to flatten it, you merely want to make it flatter than it presently is. Typically, more arc is less pressure.

Since you said it was a K frame, figured it was a .38 or .357.  All CF revolvers (.32 to .45 caliber) just need to just pick up 2 1/2 pounds. The 3 1/2 pound trigger applies to .45 autos, not revolvers (and of course 4 pounds, if it is a Service Pistol).  .22 revolvers just need to pick up 2 pounds, like their auto pistol counterpart.

cdrt wrote:Since you said it was a K frame, figured it was a .38 or .357.  All CF revolvers (.32 to .45 caliber) just need to just pick up 2 1/2 pounds. The 3 1/2 pound trigger applies to .45 autos, not revolvers (and of course 4 pounds, if it is a Service Pistol).  .22 revolvers just need to pick up 2 pounds, like their auto pistol counterpart.

...I stand corrected regarding .45 caliber. I guess the NRA feels that 2.5 lbs is appropriate for any CF revolver, but 3.5 lbs is necessary for a semi-auto. Makes solving the trigger pull weight easier.

On my J & N frames, the rebound spring had more of an effect on the single action pull, and the main springs had a bigger effect on the DA pull.

I still have to try to flatten the main spring, but as a factory spring, it is already pretty straight. The rebound spring is a factory spring. The strain screw is factory and is all the way in. I can't think of any other way to increase trigger weight and am surprised that these steps have only changed the double action pull, not the single action pull.

Hard to believe your less than 2 1/2 #!
Usually only attainable messing with sear/hooks

I put a ball bearing in the rebound spring tunnel of my International centerfire single action only K-frame to make the 3 1/4lb weight rule, easy.