S&W Hammer Spring

[arquebus357]

Here's a question for tuners.

Over and over I read and hear (youtube) warnings about NEVER using the S&W hammer tension spring to adjust trigger pull. Yet, handgun wizard Jerry Miculek instructs to do just that. He even instructs you how to trim the tension screw so it ends up flush with the grip frame. Unfortunately, my hero, Hickok45 does not weigh in on this question.

So what is the opinion here ?

[buck460XVR]

Are you talking the Mainspring?

[Mike Irwin]

OK, couple of important points...

The S&W manual was written when there wasn't the huge number of after market parts makers for S&W as there are today.

Trimming the strain screw is, in my opinion, unnecessary today because of the number of aftermarket springs, such as those by Wolff.

Trimming the screw is a one and done. You go too far and you impair the functioning of the gun.

On a match gun, maybe not such a bad thing. On a gun you're going to be carrying or using for defensive purposes? No thanks.

[Jim Watson]

Trimming the strain screw is, in my opinion, unnecessary today because of the number of aftermarket springs, such as those by Wolff.

And who else?
Where can you get a limber spring without the Wolff "power rib"?

[buck460XVR]

Originally Posted by Mike Irwin

On a match gun, maybe not such a bad thing. On a gun you're going to be carrying or using for defensive purposes? No thanks.

I'd also not do it on any of my hunting revolvers. There are other options for a better trigger pull than "Bubba-ing" the strain screw. I'd not risk my life or the buck of a lifetime, because I tried to go cheap on a trigger job.

[Mike Irwin]

Wilson also offers springs.

Sent from my SCH-I545 using Tapatalk

[MrBorland]

Originally Posted by arquebus357

Yet, handgun wizard Jerry Miculek instructs to do just that.

Jerry's a great shooter, but he does/suggests a number of things that a good many highly competent wheelgunners don't do and/or recommend.

Shortening the strain screw is a short-cut, and not a very good or wise one, either, IMO. As others mentioned, there are better ways to tune your action. Keep that strain screw bottomed out. And a teensy dab of blue Loctite on the threads isn't a bad idea, either.

[arquebus357]

Great replies.

I kind of figured that it would be thumbs down on this. I will not be playing with the hammer spring (main spring) on my newly refurbed S&W 64-3. Thanks

This forum is very helpful. A while back I replaced the hammer spring in my Ruger Security Six with a 10 pounder from a GP100 spring kit. It worked perfectly fine. I was perusing some posts here and came across one that pointed out that .357 primers require more punch than .38 special primers. It occurred to me that I had not tried .357 rounds in that Ruger. I tried a cylinder of .357 and 2 of the six required a second strike. While I had no plans to use .357's in that Ruger, it still needed to be able to shoot them reliably. Went back to the stock spring,

Again...thanks

[Driftwood Johnson]

Howdy

For the record, I have been known to back the strain screw out a half turn or so on some of my Smiths. Yeah, I know it is not recommended. I also know that the screw could perhaps loosen more from vibration. I do not carry these revolvers for self defense, they are range toys, so I am not too worried about reliability. I can always tighten the screw back all the way. In general, I do not back out the strain screw. I do most of my shooting single action, so I am not too concerned with how hard it is too pull the trigger to cock the hammer.

It also should be mentioned that if the screw is backed out too far (or shortened too much) the arc described by the main spring can become a problem. Relieve the strain screw too much and the spring will bind on the frame. What happens is that as the strain is relieved on the spring, it relaxes a bit and straightens out a bit, no longer forming the tight curve it forms when the strain screw is tightened all the way. Back the screw out enough, and the spring will bind on the frame where the arrow is in this photo. You can test this yourself, just keep backing the screw out and at some point you will notice it suddenly gets more difficult to bring the hammer to full cock as the spring binds on the frame. Don't overdo it, you might over stress the spring.






I might also mention that reducing the stress on the main spring will also have the effect of reducing single action trigger pull. This is because with the spring shoving the hammer full cock notch against the sear, there is less friction to overcome as the sear slides out of the full cock notch. This can result in a noticeable reduction in trigger pull. Generally speaking, modern (I mean made anytime after 1899) S&W double action revolvers have such terrific single action trigger pulls that this trick is not necessary. However I have used it to good effect in some of my Single Action CAS revolvers. Installing a lighter main spring will also have the same effect. Yes, I suppose I could do the 'right thing' and have a smith smooth up and slightly stone down the full cock notch on my hammers, and I have done that with a few of my single actions. But I recently purchased a S&W New Model Number Three made in 1896. It had a very heavy trigger pull, considerably heavier than a similar gun. Very few spare parts are available for these guns. Rather than grind down the original hammer spring to lighten its strength, I instead backed out the strain screw about 1/2 turn. This had the desired effect of lightening the trigger pull slightly, and I did not have to perhaps ruin a hard to find old spring.

[T. O'Heir]

"...357 primers require more punch than .38 Special..." Nope. Same primer.
"...(Youtube) warnings..." YouTube, like Wikipedia, is not the best place to get your training. Anybody can post anything they like there.
However, adjusting, not shortening, the strain screw is a low end method of lightening the trigger pull. A proper trigger job is way more reliable.

[Driftwood Johnson]

I was perusing some posts here and came across one that pointed out that .357 primers require more punch than .38 special primers.

What?

The primer does not know what cartridge it is being used in.

Are you talking about factory ammunition or reloads? Specifically what primer are you talking about?

Federal primers are 'softer' than most other brands of primers. They will reliably ignite with a lighter firing pin strike than most other brands. Many shooters who have reduced the force of the hammer spring in their revolvers will use Federal primers exclusively because of this. This became a problem a few years ago with the shortage of primers, particularly Federal primers.

If you are having problems with light strikes with 357 vs 38, there is something else going on.

[MrBorland]

Originally Posted by Driftwood Johnson

I might also mention that reducing the stress on the main spring will also have the effect of reducing single action trigger pull. This is because with the spring shoving the hammer full cock notch against the sear, there is less friction to overcome as the sear slides out of the full cock notch.

eh...not really. At least not to any appreciable level.

The main and return springs affect the double action trigger pull weight, but when pulling the trigger in single action mode, you're only moving the trigger back, so you're only working against the return (i.e. trigger) spring.

Compared to the force needed to compress the return spring when pulling the SA trigger, the tiny reduction in friction in the hammer/trigger interface when you lighten the mainspring barely has any effect on SA weight. I did the experiment. With a digital trigger pull gauge.

[Japle]

I do action jobs on all my S&W revolvers and that includes replacing the factory springs with Jerry’s Bang, Inc springs and replacing the firing pin with an extended pin.
On my competition-only guns, I back the strain screw out until the gun is 100% with my handloads using Federal primers. Those guns often aren’t reliable with other brands of primers, but I don’t care, since I’m more interested in a light DA pull than reliability with factory ammo. After all, I can always turn the screw in a turn or so if I need to.
On my hunting/defense guns, I crank the screw in until it’ll set off any primer.
I recently bought a 686 Plus, did an action job and found out that the Pachmeyer grips I wanted to use wouldn’t fit with the strain screw set where I wanted it. I ground off a bit of the screw. Other that getting a set of grips to fit, I don’t see much reason to shorten the screw.

[arquebus357]

The .357 ammo that had the light strike problem on my Security Six was PRVI PARTIZAN. That's the only .357 that I have. The .38 Special that gives no problem was mostly Remington Golden Sabers.

I do not re-load

[DPris]

Two things:

Remember that Jerry is a COMPETITION shooter, with access to a steady supply of guns & parts from S&W. His whole orientation is competition.

And, understand that Hickok doesn't get into technical aspects of anything.
You get very little useful info beyond the folksy entertainment of watching him do a talk & shoot.

Neither comment is intended to disparage either man.
Denis

[Driftwood Johnson]

eh...not really. At least not to any appreciable level.

The main and return springs affect the double action trigger pull weight, but when pulling the trigger in single action mode, you're only moving the trigger back, so you're only working against the return (i.e. trigger) spring.

Compared to the force needed to compress the return spring when pulling the SA trigger, the tiny reduction in friction in the hammer/trigger interface when you lighten the mainspring barely has any effect on SA weight. I did the experiment. With a digital trigger pull gauge.

I suppose you are right regarding a double action revolver. But I can tell you it does make a difference with a single action revolver. The mechanism is much simpler, and reducing the force of the full cock notch bearing down against the sear does have an effect on the trigger pull.

[Nanuk]

I suppose you are right regarding a double action revolver. But I can tell you it does make a difference with a single action revolver. The mechanism is much simpler, and reducing the force of the full cock notch bearing down against the sear does have an effect on the trigger pull.

The single action notch on a double action Smith and Wesson is significantly different from what you would find on a Single action revolver. Same principle, different execution.

[Jim Watson]

Wilson revolver spring. Oh Kay.

A little cheating on the strain screw is common but you shouldn't back it out far enough to distort the "arch."

Ron Power sells a strain screw with lock screw so you do not run into the problem of the strain screw shifting which can happen if the head does not contact the counterbore. Have to drill and tap for the lock screw.

Teddy Jacobsen had a strain screw with pyramidal tip that gave a quarter turn click stop in the groove of a Wolff Power Rib. Not hard to make your own out of a long set screw.

[Ibmikey]

Back out the strain screw on a self defense weapon and maybe listen to it go “click click” when you expect it to go “bang bang” and the bad guy’s goes “bang bang” when you expected silence from him. Locktite the strain screw on a defense weapon and if you use lighter springs test reliability of hammer strikes with multiple kinds of ammo.

[Rangerrich99]

Jerry Miculek also sells aftermarket spring kits for revolvers (i believe for S&W revovlers only, but I could be wrong about that). I got a set for my S&W M69 a while back. They work very nicely. There are other companies that make them, I just don't recall all of their names right now. However, a quick google search for "ruger gp-100 replacement springs" should provide you with several company names.

Oh, and many years ago when I was deciding how to adjust the triggers on my revolvers I decided against actually trimming anything inside my guns. Replace some springs, yes. Polish some parts, okay. But actually remove metal from parts? No, I'm not qualified for that sort of thing.

[Sgt127]

Very common thing to do. For years the Dallas PD armorer did trigger jobs. His signature touch was to install a small set screw in the frame with a tiny Allen screw to hold the mainspring strain screw in its slightly backed out position.

You must relieve some of the mainspring tension if you also reduce the trigger return spring tension or, you wind up with a very sluggish trigger return.

It's a balancing act. It should always be balanced heavily on the side of reliability though. But, generally, most guns are oversprung from the factory. When S&W sent a Model 10 out to ride a thirty year career in a cops holster, they compensated for a gun that would see little or no maintenance. Bone dry. Congealed grease. Dust bunnies. Freezing temperatures. Whatever. That gun was expected to go bang.

We are gun geeks as a whole. We take good care of our toys. As a matter of fact, we likely cause more wear through cleaning, polishing etc than a duty gun gets.

[Mike Irwin]

Personally I'm coming around to the strain screw method of adjusting trigger pull.

In fact, I think it's such a good idea that I'm going to remove the strain screw entirely and carry around a little smack hammer with me.

When I need to fire my gun I'll pull the trigger (see how light it is! It's incredibly light!) and smack the hammer spur with the hammer.

BANG!

Don't know why no one has thought of that before!

In fact, if you remove ALL of the springs from your S&W, the trigger pull becomes ethereally light! Almost like an angel whispering to you...

Aftermarket springs that do EXACTLY what you want are commonly and widely available from a huge range of sources.

It gives you what you want without depending on "Well, if I back the strain screw out .76125 turns AFTER I trim .01793" off the face, I SHOULD get a lighter trigger pull.... and hopefully it won't affect reliability."

Trimming/backing out the strain screw and any of a variety of other permanent but largely guesswork "solutions" is like trying to get better cornering from your car by loosening the lug nuts.

[buck460XVR]

Originally Posted by Mike Irwin

Personally I'm coming around to the strain screw method of adjusting trigger pull.

I'm sensing just a wee amount of sarcasm.........

[Mike Irwin]

Me?

REALLY?


To be 100% honest, when I'm looking at purchasing a used S&W revolver, there are two things I IMMEDIATELY look at.

First is the sideplate fit, and second is the condition of the strain screw.

If either is buggered up I ask to open the gun up to make sure that no one has been inside the thing grinding away like a monkey working a hurdy gurdy.

More than once I've discovered "home gunsmithing atrocities" based on a big old pressure ridge on the side plate where some ass pried it out or scratches or marring on the strain screw.

If I'm not allowed to open the gun, I simply walk away. No way am I going to take the chance.

A few years ago I was at the shop with a friend and I found a 4" 686 for a decent price.

Upon examination I found both warning signs noted above...

I tried the double action pull and it was... odd. Then I tried the single action pull, and I'm not even sure that it could have been measured it was so incredibly light.

In fact, it was light to the point were barely touching the cocked hammer dropped it.

Tapping on the side plate dropped the hammer.

I opened it up and I don't think there are words adequate to describe the atrocities that had been committed inside that gun. It looked like the idiot had simply opened it up and taken a dremel with a pointed grinding stone and jammed it in between the parts. It was horrible.

I flagged the owner and showed him what was going on (it was a consignment gun) and told him I'd give him $100 for it (I think it was priced at $300) and I was being generous because I was going to have to replace just about everything inside of it.

He said no. Said he wouldn't take responsibility for it being sold through his store and it was going back to the owner.


I've spent a LOT of time working on S&W revolvers. I've done action jobs on, at this point, nearly 75.

I spent YEARS working on my own guns before I started working on those belonging to friends.

And everything I learned about working on S&W revolvers came from Kuhnhausen's book.

But what Kuhnhausen had to say about some things 30 years ago when he wrote the book don't apply today because there are parts available today that were not commonly available back then.

So, my advice is...

Don't get in over your head just because you have the book.

Adopt up-to-date practices, not how it was done in the old days because that was the only choice then.

[Mike Irwin]

Oh, and I forgot to mention the most special thing of all regarding that 686...

The sideplate was warped.

My guess is because the tool with the Dremel pried it off really forcefully.