Model 659 - trigger not picking up hammer when returned to fire postion after de-cock

I'm having a lot of bad luck with my Gunbroker deals.

First the Model 59 with the light strikes, and now problems with the 659.

Here is the subject of the problem.



Here is what is happening.

1.This is an INTERMITTENT problem. I can only make it repeat on about every tenth try.

2. Empty magazine in gun.

3. Pull back slide all the way, and cause hammer to move to full cocked position.

4. Depress slide release to allow slide to go into full battery position.

5. Move selector to de-cock position.

6. Hammer moves to full "forward" (down) position.

7. Move selector to fire position.

8. Pull trigger while magazine is still fully in place.

9. Feel slight "catch" during trigger-pull, and hammer moves only very slightly as trigger fails to cause hammer to move in normal fashion.

10. Trigger moves to full "pulled" position while hammer remains in full "forward" (down) position.

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This does not only happen during dry-fire cycling as described in 1-10 above. I had two incidents of this happening during live fire yesterday. Two different Mec-Gar mags, each loaded with 17 rounds.

1. Mid-way through the mag, the trigger would not cause the gun to fire. No amount of trigger manipulation would cause the gun to fire.

2. The gun would fire.

3. The slide picked up a new round from the mag.

4. The slide would chamber the round in full battery.

5. The hammer would be fully cocked.

6. I would pull the trigger.

7. Pulling the trigger would not cause the hammer to fall.

8. I could feel a slight "grabby" sensation in the trigger as I moved it back and forth with no functional effect.

9. I was able to clear the failure by racking the round out of the chamber (live round ejected, and showing no sign of firing-pin strike). Then the gun would operate correctly until the next magazine where another failure occurred.

10. It may have been possible correct the failure by moving the selector to de-cock the hammer, and then fire the existing round by pulling the trigger in "double-action" mode; or maybe even by re-cocking the hammer manually to allow "single-action" fire. I did not attempt either of these methods, as my greatest interest was to inspect the round in the chamber. Most likely, either of those methods would have allowed me to fire the round in the chamber if I had wanted to do that.

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I cleaned this gun meticulously today. It is so clean, inside and out (including the mag-disconnect plunger and the firing pin safety plunger, and firing pin channel) that I could eat off the surfaces.

The problem with the trigger failing to pick up the hammer persists.

Here are some pics of the "innards."
Everything looks almost brand new to me.





I removed the mainspring housing, and the grips, so I could get a the best look available for inspecting the notches on the hammer. I could see nothing that appeared damaged or missing. I did not attempt to remove the hammer axis pin to get at the sear.

Is this type of malfunction a "known issue" that has a particular fix?

Remember, I am not the original owner. The gun shows signs of very little previous use.

The previous owner did send this gun in for an official recall regarding an issue with the selector.
See Firearm Recalls and Safety Warnings- FirearmsID.com
This was the issue that had to do with guns that would not fully de-cock from the half-cock notch by use of the selector. I am NOT experiencing that issue with this gun. The selector will cause it to fully de-cock from any normal hammer position. The "barrel" of the selector is marked with a letter "S" if that means anything.

I have successfully assembled a number of old military guns part-by-part. So, I'm fairly handy when it comes to working on guns. But, I'm unfamiliar with what works best with this particular gun. If any of y'all have a good idea how to approach this before I just buy one of every available sear size, and start playing plug-and-play on Old Betsy, I'd be much obliged if you could share your knowledge and experiences.

Here is a copy of the repair invoice that the prior owner said he received after sending the gun for attention relating to the recall. I assume the gun was sent to an "authorized repair station" rather than to the Smith and Wesson factory. Appears to say that the sear release lever (middle lever in pic above?) was replaced. Seems to me that something didn't get done right.

It could be the trigger is not returning fully forward. Can you check to see if coils have been removed from the trigger return spring?

KAC

KAC said:

It could be the trigger is not returning fully forward. Can you check to see if coils have been removed from the trigger return spring?

KAC

Click to expand...

I have not physically removed the trigger return spring.
I have visually inspected as much of the trigger return spring as can be seen during a field strip. I see no evidence that the trigger return spring has been damaged or altered.

The return-tension on the trigger of the 659 feels consistent with the same tension on my model 59, and three model 39's.

Before posting this thread, I hand-cycled the 659 at least a hundred times while studying the malfunction. In every case the trigger returned to its full forward position normally, except when the malfunction would allow the hammer to be fully cocked, and the trigger not able to make the hammer fall. I this situation, the forward-return motion of the trigger would be arrested at about the same spot as the trigger would be positioned during normal "single action" fire.

Do you have a spare ejector that you can try in the gun? The magazine disconnect feature may be the problem with the ejector in the gun now.

KAC

I don't have any spare parts for this gun, but I'm prepared to buy whatever replacement parts might solve the problem.

Just to be sure we are talking about the same part, the "ejector" is the dingus-lever that presses against the magazine-disconnect plunger. Is this correct?

I'm referring to the lever appearing in the bottom of this pic.

Is there something about the ejector lever that would indicate it to be defective by visual inspection?

W.E.G.,
Yes, that is the part I was referring to. Fastbolt will have more info, but, with the slide off the frame you will probably have none of the failures you have been experiencing. With the slide on the bottom of the ejector is probably riding on the trigger bar, pushing it away from the hammer.

KAC

Sounds like a problem with the drawbar(trigger bow) or disconnector. Can't tell from your pictures but is the disconnector coming back up out of it's hole on it's own?

KAC said:

W.E.G.,
With the slide on the bottom of the ejector...

Click to expand...

Do you mean TOP of the ejector?

handgunner356 said:

...is the disconnector coming back up out of it's hole on it's own?

Click to expand...

Does this pic answer the question?

I'm thinking about removing this part so I can do further inspection.

My understanding is that this is the hammer axis pin, and also the axis pin for the various levers in that same area.

With the grip panel off the gun, it looks like I can just slide this part right out. What I DON'T KNOW is what will happen with all those little levers and springs. Will I need five hands and a witch doctor to get the parts back in if I pull the pin out?

Rather than create your very own "kitchen-table gunsmithing" nightmare, why not call LSG and discuss sending it back to them? The 2nd & 3rd gen S&W TDA guns aren't the easiest to detail strip, especially if you haven't been shown how to do it and have gained some experience doing it a number of times.

While diagnosing problems with guns isn't something that can be properly done online, a few thoughts occur to me ...

The first condition described sounds suspiciously like a Skips Double Action problem. If so, it's usually caused by a defective hammer, drawbar or disconnector. Could be worn pick-up notches on the drawbar or the hammer (the first set of notches on each part). Could be a "long tail" disconnector problem. Could be a cracked/broken drawbar (at either rear corner, or in the center, to one side or the other of the disconnector tab). Maybe even a short or broken drawbar spring, or the small channel in which the spring and plunger are located is very, very dirty.

Installing a new drawbar comes with its own potential issue, though. Sometimes a new drawbar will still allow Skips DA to occur in a particular pistol, but not because of the notches. On rare occasion a new drawbar may have to have the radius of the drawbar head filed (with a 5/32" chain saw round file) toward the locating hole until enough metal has been removed for the drawbar to be able to engage properly with the hammer in a particular gun. Over-filing, however, can create something of an opposite problem, called "long throw". In this situation the drawbar can't pull the hammer fully to rear and release it before the trigger bottoms out against the rear of the trigger guard. (I've only had to file the radius on ONE new drawbar in the time I've been an armorer, though.)

In the last couple of 3rd gen guns brought to me for problems that turned out to be Skips DA conditions, the drawbars and hammers had to be replaced. One gun checked out fine after the new parts were installed, but the other one still exhibited the Skips DA problem, although seemingly to a lesser extent, with the new hammer and drawbar. It turned out to be the gun which resulted in me carefully going over my notes in my oldest armorer manual about having to file the radius of a new drawbar. It resolved the problem and the gun went back into service functioning normally again.

The second condition can possibly involve the disconnector & drawbar as well. The gun fires in SA mode by having the drawbar pulled forward during the SA trigger stroke, contacting and pushing the sear body forward, causing the sear nose to be pushed out from under the hammer's SA cocking notches. As the drawbar is being moved forward, it also raises the disconnector (which rides on the drawbar's disconnector tab). If the disconnector is obstructed in some manner from its upward movement, it can prevent the drawbar from moving at the proper height so that it contacts the sear.

Checking for a broken drawbar involves removing it from the frame and grasping it on each side, pulling outward as if trying to "spread" the drawbar at the middle or rear. A break at either rear corner, or in the center, will become apparent.

Like I said, though, I can't pretend to know what's happening with a gun unless I have it in front of me.

It would probably be prudent to have it examined and repaired by a gunsmith familiar with S&W TDA guns, the factory's repair center or even a S&W armorer (if you know one in your area).

It's late, and these are just some thoughts based on what you've posted.

Call and arrange to get it checked out and fixed.

Wow!

Thanks for the very detailed reply!

I think I'll just send it to Smith and Wesson in Massachusetts, and take it on the chin for whatever will be the cost of the repair.

Don't think I'll chance it with the Texas outfit, as they apparently did not detect the problem when it was in their custody before, if they were not the ones who CAUSED the problem.

I've done my share of "home gunsmithing" projects, and have had good luck with all but those that involve removing metal from the fire-control engagement surfaces. The current problem sure is starting to sound like exactly that sort of issue. I'm at least the third owner of this gun, so who knows what sort of muckery the fire-control parts have been subjected to.

Thanks for all the help, and I'll post a follow-up as the factory repairs proceed.

Don't see how it could be attributed to something that happened during the earlier repair. I'd think it's not implausible for the problem to have developed after the company did the other work last year, if the gun was being fired afterward (live or dry-fire), or even for it to have been present to some degree but not noticed because it didn't manifest during the 10 rounds they fired. If you look around some of the threads in this forum I think you'll find those folks are well respected, and they are a S&W warranty service center. Nothing wrong with sending the gun home to Springfield, though.

When a new drawbar and/or hammer are installed the armorer checks the fit & function with the usual bench checks.

The tension of the drawbar spring is checked to make sure the tail of the drawbar lifts and is under spring tension (so it reaches up to engage the hammer notches). The nose of the drawbar plunger has to be located within the small depression on the front of the drawbar head (it can slip out of position during reassembly if not carefully watched when moving the drawbar back into proper position to accept the trigger and then the trigger pin).

The disconnector has to be able to ride up & down the drawbar's disconnector tab, and be lifted, without resistance.

The trigger is checked in SA to make sure it holds (no "push off").

The trigger is functioned in DA several times to make sure the drawbar catches the hammer's pick-up & then throw notches for normal DA function. The trigger is also "rocked in DA" to make sure the hammer doesn't slip off (no rounded edges).

Check for hammer bind.

Then the live fire check is done when everything looks good to go.

I've had to function a DA trigger a couple of dozen or more times to detect a developing Skips DA problem in some guns, and then could repeatedly detect it in only a few DA trigger strokes in another gun. Just depends on the condition of the parts and the extent of the problem.

I'd be interested in hearing the results of your repair, to see if my late night conjecture and thoughts were anywhere close to being accurate.

Repair is much easier when a problem is accurately diagnosed. Nothing beats having the gun in your hands when it comes to trying to diagnose the problem, though.

Fastbolt,
Thanks for the great info.

KAC

De nada.

Doesn't mean I know what's wrong with the OP's gun, though. I'd really need to handle and examine it.

That being the case, the info I related might be interesting, but not useful to him.

Dropped off the 659 at my dealer today.

Should ship to S&W by Friday.

Out for Delivery, January 31, 2011, 8:06 am, SPRINGFIELD, MA 01101
Sorting Complete, January 31, 2011, 7:56 am, SPRINGFIELD, MA 01101
Arrival at Post Office, January 31, 2011, 4:12 am, SPRINGFIELD, MA 01101
Processed through Sort Facility, January 30, 2011, 11:17 pm, SPRINGFIELD, MA 01152
Electronic Shipping Info Received, January 28, 2011

I know it is too late, and I hate to give up one of my best secrets but here goes.

Take the slide off.
Look down into the action at the top of the trigger bow.
See the little copper colored spring riveted to the top of the trigger bow?
Are the fingers standing straight up or slightly bent down?
If those little spring fingers are not standing straight up it can cause the condition you describe.

The small copper colored spring on the front of the drawbar is the trigger play spring. It's function is to remove excess "play" in the trigger when the gun is in the SA cocked condition. The gun will function normally even if the spring is broken off, and likely the shooter won't even feel the difference in the SA trigger. (The CHP here in CA ordered their newest 4006TSW's without the spring, and removed them from their older 4006's some time ago.)

The spring that tensions the drawbar and lifts the tail (to allow it to engage the hammer's notches in DA) is a coil spring which is located in the frame directly in front of the drawbar, running front-to-back. You can see the rear of it (and the head of its plunger) when the slide is removed and you look down into the frame at the front of the drawbar head.