Lightening Revolver Trigger Pull

As I said, I have successfully reduced trigger pull on a SAA to 2 1/2 pounds by simply grinding the hammer spring down without doing anything else.

Of course a S&W revolver is not the same as a SAA.
 
Anyone who has experienced match pressure (as in bullseye competitions) knows that a light 2.5 pound crips trigger break in SA can feel like a ton.
It's called "chicken finger".

And now I've come to realize that the lighter the trigger the more this might happen. Because the light trigger forces the shooter to have a light touch. And of course what happens when one is nervous? As in SD training, your fine motor control goes out the window. So there might be an argument for a heavier trigger forcing the shooter to take more control over the trigger.

That's why sometimes in a pistol match shooters actually shoot better in rapid fire than slow fire. Because they have to take better control of the trigger.

After years of (bullseye) training with super light triggers, I have now in SD training come to appreciate some advantages of heavier triggers and enjoy DA shooting much more.
 
Thanks everyone for the replies. there is a lot of good info in this thread! Losing the screw wouldn't be an issue, because I have target grips that wrap around the screw. Also as far as reliability is concerned, it is a range toy, so this doesn't concern me in the slightest. I have experienced the hammer having a weird feeling when cocked if the screw was backed out too much so I screwed it in enough so it didn't happen. After reading through all of this it seems the drawbacks are negligible for my purposes. thanks again. :)
 
Not the best method. Will it damage the gun? Not if you don't go over board. Will the strain screw be lost? Not if you don't over board. The screw is still under load if you just back it out just a little.

However, gunsmiths and people in the know protest against it. Anybody can do it any it generates little income.

The strain screw pretensions the main spring. It changes the force and position of the main spring. Backing it out lightens the trigger, but it also changes its pull profile, the graph of force verses travel. It is essentially the same as shimming the spring. But if that's what I like, why not?

I do that all the time to my own guns, because I happen to like some stacking in my trigger. I am doing part-time smithing. Certainly I won't do it for my clients, as it makes me look amateur and I need the work. I will do shimming though, if they don't mind the changed trigger profile.

-TL
 
"...an effective way..." No. It does that(tightening the strain screw all the way in isn't necessary either.), but it's not a proper trigger job. Loosening the strain screw too much will cause unreliable hammer strike.
A proper trigger job involves polishing all mating trigger/hammer surfaces and changing the springs. Just changing the springs will help, but not as much as polishing and changing 'em.
 
Old Dallas PD gunsmith used to drill a tiny hole in the side of the grip frame and installed a set screw that locked the main spring strain screw as part of his trigger job.

It worked well and there were alot of DPD guns modified that way.

I usually just filed down the end of the strain screw to slightly lighten the DA pull. And, yes, I have a little box of strain screws that "missed it by thaaat much" and, wound up too short for reliable ignition.
 
I have polished all contacting trigger surfaces, not including the SA hammer sear engagement surface because I don't have the proper tools or skill to not mess that up. haha. It smoothed the DA pull out a great deal, combined with the loosening of the strain screw and the 1.5 coils I cut off of the trigger return spring it lowered the pull weight too. SA must be about 2.5 lbs. Plus my sight alignment doesn't even budge when I pull the trigger in DA. I seriously can't wait to take it to the range now.
 
If you shoot it much, you'll eventually notice the screw backing itself out farther.

Don't depend on that gun for SD.
Denis
 
dahermit said:
...the strengths of the main and return springs are designed to be balanced, since they work in concert.
Click to expand...

Can you explain exactly how they are designed to work in concert and what would happen if they did not?
Click to expand...

The mainspring tensions the hammer, whereas the rebound spring tensions the trigger. Upon trigger return, the trigger physically resets the hammer, so it has to work against mainspring tension. Because double action moves the hammer and trigger, the DA pull is a function of main and rebound spring tensions. In contrast, single action just moves the trigger back to break the shot, so the SA pull is mainly a function of the rebound tension.

The main and rebound springs should be balanced. A stock DA revolver has a DA:SA pull ratio of about 2.5 - 2.7, and it seems to me a good reference when swapping springs.

If the main is relatively heavy compared to the rebound (or, said another way, the rebound is relatively light), the trigger will be sluggish resetting (in extreme cases, the trigger will inconsistently return to it's fully forward reset position). Shooters who shoot DA and ride the trigger on the return (a very common habit that most wheelgunners don't realize they do) will find themselves short-stroking the gun. Shooters who shoot SA will find they've got a very light SA trigger.

If the main is relatively weak compared to the rebound, you'll have a DA pull weight that's heavier than it needs to be for the reliability you've got. The whole point of running "Federal-only" loads, for instance, is to significantly reduce DA pull weight.

Driftwood Johnson said:
In this photo I have backed the strain screw out too far. I am encountering resistance to the hammer going back all the way to full cock. What is happening is the new curve the spring took is forcing the stirrup to pivot too far.
Click to expand...

Interesting. Good to know.

Driftwood Johnson said:
Competition shooters have known for many years that they can lighten the double action trigger pull by grinding the rebound slide spring shorter.
Click to expand...

IME, competitive wheelgunners (IDPA, USPSA, ICORE) lighten the double action by adjusting both springs (and as part of a good action job) for the reasons articulated above.
 
In this photo I have backed the strain screw out too far. I am encountering resistance to the hammer going back all the way to full cock. What is happening is the new curve the spring took is forcing the stirrup to pivot too far.
Click to expand...

To explain it a little bit further, since the stirrup cannot pivot anymore, trying to cock the hammer is shoving the stirrup down. Normally as the hammer is cocked, the pivoting stirrup bends the spring in the normal way. But once the stirrup binds against the body of the hammer, the spring gets shoved straight down, greatly increasing the effort needed to bring the hammer all the way back to full cock. I experimented with backing the strain screw out about 1/4 turn more, and I could not get the hammer to full cock position at all.

Then I snugged the screw back up the way it is supposed to be.

The way the gun left the factory.
 
The only thing I will do to lighten the trigger in my S&W's is to put in a slightly lighter rebound spring. I never replace the mainspring for reliability reasons, and I wont drop too low on the rebound spring as to ensure reliable reset.
 
People used to back out, or even shorten, the strain screw for the same reason they lopped coils off the rebound slide spring -- because at one time that was the only "simple" way to change them.

There weren't reduced/increased power spring sets. You stuck with what you had, or you made changes like that.

Using the strain screw to control mainspring tension to give a somewhat lighter trigger pull is self-defeating.

At the worst possible time the screw will back out just enough to cause the mainspring to knuckle (which means that it is trying to compress along its length). This can make the gun difficult to impossible to cock, and it will also GREATLY reduce hammer power to the point of misfires.

Not a problem with a range gun. BIG problem with a defensive gun.
 
In a pre-MIMS S&W double action revolver (and, for all I know, also post-MIMS revolvers, but I don't work on them), the trip weight of the single action release is dominated by the rebound slide spring, while the trip weight of the double action release is dominated by both the rebound slide spring and the mainspring. Contrary to what someone suggested, the "weight" of the main spring makes no detectible contribution to the weight of the single action release.

As noted, trigger release trip weights can be adjusted, and usually improved, by installing Wolf spring kits. And has also been suggested, a person competent in stoning the sear surfaces of the trigger and sear surfaces can improve the single action release, though this process requires specialized tools, specialized skills, and a bucket of replacement parts to which to resort when it isn't done properly; i.e., not recommended for most folks.

All that said, however, there are things that can be done by mere mortals that will improve the feel of the double action release; not the weight, but the smoothness, which is more important than weight and will often be mistaken by users for light weight. What you want to do is completely clean and then lightly polish certain friction surfaces, such as the bottom and sides (not the top) of the rebound slide and the frame parts that constitute the tunnel through which the rebound slide moves, plus the pins and bosses for both the hammer and trigger. Clean again after polishing, and then lightly lube these surfaces with light gun oil (not grease).
 
What you want to do is completely clean and then lightly polish certain friction surfaces, such as the bottom and sides (not the top) of the rebound slide and the frame parts that constitute the tunnel through which the rebound slide moves, plus the pins and bosses for both the hammer and trigger. Clean again after polishing, and then lightly lube these surfaces with light gun oil (not grease).
Click to expand...
For those of us who do not go outside to shoot in cold weather (has to be above 60 deg. F.), why not use grease?
 
A bunch of reasons. The parts in question are too small and light not to be adversely affected by the viscosity of grease. Ditto the spring forces involved. Add the superior capacity of grease to accumulate particulates and turn them into concrete. And, if none of that convinces you, the fact that Smith & Wesson has taught those who make and service the DA revolver not to use grease.
 
Significant reasons why you should use grease on the internals of your revolvers:

1. Grease, unlike oil, stays where you put it. It doesn't flow away from the surfaces over time, leaving them unlubricated.

2. Revolvers are far more "closed systems" than semi-autos, meaning the potential for contamination is in reality no greater with grease than it is oil, and the contamination process is FAR slower overall.

3. Properly selected greases will continue to lubricate in all weather conditions -- not all greases solidify if the temperature drops below freezing.

4. While grease will hold any contaminates into proximity with the parts that it's lubricating that is easily rectified with a proper, regular cleaning routine.

5. While grease is thicker than oil, and will cause greater action drag, that is easily rectified by choosing a light bodied grease and testing the application to make sure that it's not causing unacceptable action dragging. In the more than 30 years I've been using grease on my S&W and Colt revolvers, I have never seen a light-bodied grease produce enough resistance to hang up a gun, and all of my revolvers have reduced weight main and rebound slide springs.
 
Yes, if you're gonna use grease, it ought to be a low viscosity grease. TW25B works great in a revolver. Other than that, I use good old ATF.
 
I really liked Slick-50 wheel bearing grease for Competition DA revolver trigger work. It only requires the finest film. Do you trigger work, apply a film, dry fire it, clean, and apply fine amount of grease.
 
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