Why don't S&W triggers stack?

[Croyance]

Not that I am complaining. But after getting my first revolver, I have been looking around and handling more. I am struck by the fact that S&W's best competitors, Colt (in the past) and Ruger have trigger pulls that get heavier as the sear gets closer to tripping. Taurus trigger pulls are . . . not likable.
So what is unique about the S&W design? Why don't the competitors have similar designs? Are their inherant weaknesses or flaws to it?

 

[RON in PA]

It's a matter of design geometry. Colt DAs are known for stacking. Rugers are pretty good, almost up to a Smith. Some people like the stacking as it lets them know when the gun is about to fire. Smith has advised, in its manuals, that proper DA technique is a continueous squeeze with no hesitation. Certainly their triggers are well suited for that technique.

 

[Majic]

The flat leaf spring of the S&W gives constant pressure thru out it's range of motion. The older Colt action has a "V" spring that requires consistantly more pressure as it compresses. When S&W used it's old long action (Pre-war guns) the triggers would somewhat stack.
The best attribute of a stacking trigger is for target shooting. You can load the trigger until it stacks, realign your sights, then finish your pull. The S&W with it's constant pull makes it harder to judge where the sear will release so you can get that final sight adjustment.

 

[MCgunner]

I was amazed at the "stacking" at a SP101 I tried recently. It broke at probably 15 lbs. Fortunately, on a Ruger, that's easy to cure. My Rossis are very Smith like and the little M68 snubby has a good trigger. My Taurus M85UL has a fantastic light, smooth trigger with no "stacking". It's a smoother trigger even than my old 50s era M10 Smith. I don't know how you think Taurus has bad triggers, because this one is delicious. My older M66 Taurus ain't that great, but it's not bad. It's not as good as my M10, though, grittier and a little heavier. But, it doesn't stack all that much.

I like a DA that stacks for target/range work and especially want this feature in a DAO. My P11 Kel Tec does this, very smooth, stacks just a tad at the end to let you know it's about to go bang. That makes it easy to place my shots and I can put 'em into 3.5" off the bags at 25 yards with that tiny little gun, pretty amazing to me considering the short sight radius. Mowing down a row of 6" plates at that range off hand is no problem at all. But, then, I shoot this thing a lot, nearly every range trip, and I've had it for a little over 8 years, so the trigger has smoothed and I've become one with the gun.

 

[Brian Williams]

I do not need a trigger that stacks or gets heavier at the end, a properly timed S&W will lock up just before it fires. A good Smith shooter will know when that second click happens, realign the sights cause it is ready, and just a little more pull and it will go.

 

[Old Fuff]

When properly fitted S&W revolvers with a leaf mainspring shouldn't stack, (and this in particular includes the pre-war "long-action" guns that potentially have the best double-action ever made). As the hammer comes back the spring passes over center after about 3/4 of the stroke, and thereafter the pull weight actually drops!

Coil springs increase tension until the hammer is released, but the effect on the hammer can change if the spring and hammer strut is allowed to move as the hammer comes back because this changes the way and angle the hammer is being pushed. However as a rule of thumb, the lighter the hammer is the heavier the spring must be to insure reliable ignition. The actual distance the hammer falls makes a difference too, so "short actions" require heavier springs.

In older Colt's with a "V" mainspring what causes the stacking feel is when the two leafs come together before the hammer has gone through it's full travel. Sometimes this can be eliminated by "reforming" the spring, but don't try it on a pre-war gun with a forged spring or you'll likely break it.

 

[gunfan]

I do not need a trigger that stacks or gets heavier at the end, a properly timed S&W will lock up just before it fires. A good Smith shooter will know when that second click happens, realign the sights cause it is ready, and just a little more pull and it will go.

That sounds like the Smith & Wesson revolvers that I have. I like it that way.

Scott

 

[WT]

I like the short 'pause' of the S&W. Gives me a final chance to line up the sights before making a loud noise.

 

[Croyance]

MCgunner, I've experienced a Taurus that felt like fine grit was inside. Bad trigger pull. Then another that always needed tightening. And one with a rough pull. I gave up.

Even without stacking, shouldn't an experienced shooter know by feel when (s)he is getting to the point where the sear will trip? I used to do this with a Para-Ordnace LDA, little knowing that people had been using the same trick.

So is there any desirability for stacking in a non-target shooting?

 

[Standing Wolf]

In older Colt's with a "V" mainspring what causes the stacking feel is when the two leafs come together before the hammer has gone through it's full travel. Sometimes this can be eliminated by "reforming" the spring, but don't try it on a pre-war gun with a forged spring or you'll likely break it.

Thank you, Old Fluff! I knew that, but never understood it.

Is there much danger of breaking a Python V spring while reshaping it?

 

[Old Fuff]

Standing Wolf:

Is there much danger of breaking a Python V spring while reshaping it?

No, because Python mainspring were formed out of flat spring-stock, and then heat treated.

Remove the stocks and watch the mainspring as you cock the hammer. See if the leafs come together before the hammer reaches full-cock, and if so, how drawing back the hammer becomes more difficult. When this happens take a 1/16" Dia. punch and insert it between the leaves as far back as you can, (or about 3/8" from the back) and then cock the hammer while the punch is in place. Lower the hammer and remove the punch. Then cock the hammer again and see if there isn't some improvement. At this point the leaves should just lightly touch at the back when the hammer is at full-cock.

Don't do this adjustment if there is evidence that its already been done previously. Otherwise you may end up with a spring that is too weak.

 

[JMusic]

Well they do stack just not as bad as the others. The trigger leaf is not the only spring that is in play here. Advantages to a Smith is the shorter trigger stroke. Wolf spring additions and some polishing will certainly minimize the stacking but it does not go away. Best trigger single and double I've seen though was on a Python, which I happen to own.
Jim

 

[Standing Wolf]

Thank you, Old Fluff! If I'd known it was that easy...

 

[Surefire]

Depends on individual guns. I have Rugers with ZERO stacking, and a S&W (newer design with coil spring) with moderate stacking. My best S&W trigger has zero stacking and butter smooth action--and it has the older leaf spring.

Overall, S&W triggers (especially the older "-4" and before variations) will be smoother than Ruger triggers, but there are exceptions.

 

[Dave Markowitz]

Smiths don't stack because they are designed correctly.

Seriously, none of my K or N-Frames stack. My one J-Frame, a Model 640 (no dash) does stack a little, but has a coil mainspring instead of the flat leaf springs on the Ks and Ns.

I have two Rugers: a Service Six and a GP-100. They may stack a little, but it isn't very noticeable.

 

[Jim K]

Hi, guys, especially Majic and Old Fuff,

Sorry, folks, but the spring has nothing at all to do with it. S&W revolvers would work the same with a V spring or (as they do) with a coil spring.

If you have access to a Smith & Wesson and can remove the side plate,* look closely at the bottom of the hammer and the back of the trigger.

Now pull the trigger slowly, DA. First, like the Colt and Ruger, the top of the trigger contacts the hammer strut (S&W calls it the "sear"). Continuing the trigger pull raises the hammer. But when the trigger moves the hammer back a bit over halfway, a spur on the back of the trigger below the top engages the toe of the hammer below the SA notch. As the trigger comes back more, the sear is out of the picture, not touching the trigger, as the job of pushing the hammer back the rest of the way is taken over by the two lower engaging surfaces. This transition is so smooth that most people don't even know it happens.

Since those camming surfaces are closer to the pivot points of the hammer and trigger than the sear, the leverage is increased enough to compensate for the increasing tension of the spring. And that, folks, is why S&W revolvers don't "stack".

Colt repeatedly spent lots of money trying to shape their hammer strut (they do call it that) to try to eliminate stacking, but without using S&W's system they just could not do it. Neither has Ruger.

*Before doing this, it is best to release mainspring tension and also to remove the rebound slide to take tension off the studs.

Jim

 

[JMusic]

Jim, have you tried fitting a ball bearing into the rebound slide? I first noticed this from a 586 that was worked on from the performance center. It really seems to help on smoothness and trigger speed return.
Jim

 

[Jim K]

No, I don't think that trick was "in" when I was working. What I did do was to set the rebound slide up in a milling machine and cut wide shallow grooves (about 1/3 of the width) down the center of the bottom and sides, leaving fairly narrow rails. This reduces the friction surfaces.

Jim

 

[pezo]

I was amazed at the "stacking" at a SP101 I tried recently

This is true. with my dao sp101 I can pull the trigger and keep it stopped before the point of hammer drop.At this point the cylinder is lined up with the shot to be fired and the trigger is in at a SA like pull. This gives me SA like accuracy out of the dao peice, using trigger control only. I like this characteristic.