3913 trigger question

[tocohillsguy]

What is the stock hammer spring weight, and has anyone tried to go with a lower weight? How low can one go on the hammer spring weight before light strikes become a problem?

 

[VASCAR2]

Hammer Spring

Wolff Gun Springs list 20 pounds for the hammer spring. Wolff showed some pistols in group B which includes 3913 shipped with a Factory reduced 17 pound spring. Personally I would not change a hammer spring on a 3rd Gen S&W.

https://www.gunsprings.com/SMITH & WESSON/NUMBERED SERIES/cID1/mID58/dID261

 

[stansdds]

Keep spring weights stock. S&W put a lot of effort into determining which spring rates worked to create a reliable pistol. Changing spring rates can result in malfunctions or a pistol that beats itself to death.

 

[BLUEDOT37]

What is the stock hammer spring weight, and has anyone tried to go with a lower weight? How low can one go on the hammer spring weight before light strikes become a problem?

Sometimes I use a reduced power Wolff hammer spring in my 3rd Gens. Occasionally a 19# which I have in my 3914.

I do have a 17# (Wolff's lightest) in my 3914DAO NYPD model & I haven't had any issues with it, or any of the others, & I handload using CCI primers which are commonly called the hardest primers.

Probably a good idea to keep the firing pin tunnel nice & clean if you go with the lightest one. If you carry it for SD it's your call but test, test, test, to be sure.

And since the hammer spring also helps to initially slow the slide, by the hammer's force against it, I go up a couple pounds on the recoil spring in this situation. (I went from the factory 15# to a Wolff 18# recoil spring in the 3914DAO. I shoot +P only in my 9mm's.)

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[tocohillsguy]

What sort of improvement can one achieve with a change in the springs vs. a quality gunsmith action job? Presently I'm at 12.5 pounds double action, and 6.5 pounds single action.

 

[BLUEDOT37]

I thought I had some readings reflecting the reductions in trigger pull weight but can only find ones, right now, when I increased the mainspring weight.

When I went up 3# on the mainspring the SA pull went up 1# so the reverse is likely when going with a lighter mainspring.

You do "feel" the difference in the lighter spring more in the DA pull than the SA pull though. My current trigger pull gauge is only good for SA pull measurements unfortunately so I don't have any numbers I can share on DA weight. One day I'll invest in a better gauge.

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[twistedracer]

Here are the measurements I had noted from my 3913 Ladysmith.

With the stock mainspring, the DA was over the 12 lbs max my electronic Lyman would measure.
SA was 6 lbs 14 oz.

With the 17 lbs mainspring, DA is 11 lbs 12.5 oz.
SA is 6 lbs 2 oz.

The most noticeable difference for me while shooting is in the DA pull. Hasn’t failed to ignite my defensive ammo or practice Ammo. No felt difference in recoil.

 

[tocohillsguy]

My original measurements with stock springs were 6.5 SA and 12.5 DA, and the trigger wasn't very smooth. There are some 3rd gen gunsmithing videos posted on YouTube. I polished the recommended trigger related areas and couldn't measure or feel much difference. I then changed the trigger spring to 2.5 lbs and the hammer spring to 18 lbs and dropped 1/2 off both the single and double action pulls, but the trigger remained gritty. I then stoned and polished the radius of the hammer (stayed away from the hooks and transition dip) and achieved significant improvement in the smoothness of the trigger. The forged hammer had a lot of tooling cut marks. I prefer the traditional forged parts, but I believe the MIM hammers and sears provide a better trigger pull out of the box. Other than dropping the hammer spring to 17lbs, or perhaps messing with the hooks (which I would never do) I'm not sure if there is any more that can be done. For the benefit of other readers, I believe my efforts reduced the trigger to approximately 11.5 DA/5.5 SA.

 

[stansdds]

Pistols with MIM fire control components are often much smoother than the forged parts. The MIM pistols also have a more uniform trigger action from one pistol to another.