Model 39 Decocker Malfunction

[Dennez]

Hey Folks.

The decocker does not seem to function correctly on my pistol. Before reaching out to you I confirmed the problem with and without magazines in the gun and with and without ammunition in the magazines.

Without a magazine inserted and after racking the slide the decocker will usually only decock the gun on the second attempt.

With a magazine inserted, with or without ammunition The decocker becomes unfunctional (will not drop the hammer).

With a magazine inserted, with or with out ammunition and after racking the slide (releasing the slide w/o ammo) the decocker becomes unfuctional.

Leaving a round chambered and after removing the magazine the decocker remains unfunctional.

And there have been cases after clearing the gun of ammunition and removing the magazine that it requires reracking (is that even a word) a several attempts to have the decocker function.

If the gun is racked and the decocker is left in the safety position the gun will always move into battery position decocked as it should.

So what is or could be wrong with the decocker? Or is there another mechanism in play here stopping the decocker from doing its job?

I appreciate your help folks.

Dennez

 

[JohnHL]

Hi, Dennez!

Sounds like it's time for your sear release lever to be replaced.

To test, when your pistol refuses to decock (when you have a magazine in), press down on the rear of the slide and try to decock again.

Odds are it will.

Over time, there is wear between the slide and frame and when the slide is pushed up, away from the frame by the magazine spring, the safety body can no longer push the sear release lever as far as it needs to be pushed.

Replacing the old sear release lever with a new, fitted part will solve the problem.

John

 

[ACEd]

If I remember correctly there was a recall for a decocker issue on 39 & 59 and maybe 439 & 459 pistols within a certain s/n range - dont recall the specifics, but you should be able to search forum or internet search something like "Smith Wesson 39 recall"
Quick search seems to indicate 439, 459 and later 3 digit models but not the 39, 59 2 digit models. But they describe a test to see if pistol is affected. May be worth a look.

S/N Range A745000-A865000 and TAA0001-TAL9999

 

[Dennez]

Thank you, JohnHL and thank you, ACEd.

My pistol is from the 81000 - 82000 lot.

I found a Sear Release Lever on Ebay for $7.99. Sound too good to be true to find one so quickly. Please see the picture. Does this one look OK?

Thank you, again.

 

[S&W59]

Thank you, JohnHL and thank you, ACEd.

My pistol is from the 81000 - 82000 lot.

I found a Sear Release Lever on Ebay for $7.99. Sound too good to be true to find one so quickly. Please see the picture. Does this one look OK?

Thank you, again.

Sear release arms are custom fitted to the pistol. What works for one pistol does not work for others. I had a similar problem with a S&W 5967 and it took me four sear arms to find one that did the job correctly. I had to hand fit the sear arm by sizing the point at which the lever engaged the sear. Took me four tries but I finally got it. I recommend getting a new never installed sear release arm from Numrich.

 

[ACEd]

Sear release arms are custom fitted to the pistol. What works for one pistol does not work for others. I had a similar problem with a S&W 5967 and it took me four sear arms to find one that did the job correctly. I had to hand fit the sear arm by sizing the point at which the lever engaged the sear. Took me four tries but I finally got it. I recommend getting a new never installed sear release arm from Numrich.

Agree - get new one - they are not expensive - Numrich, Brownells, Midway are good sources for parts. Careful buying used parts. And check prices - saw some used 5906 grips on eBay for $49 - but you can get new from above sources for around $20
Best, ED

 

[Green Frog]

I must be the exception to the rule. I had the same problem with my 639 and when friend JohnHL gave me this same advice, I pulled a used but nice looking example out of a “parts kit” I had acquired for just such eventualities and PRESTO the problem disappeared. Sometimes it’s better to be lucky than good!

Froggie

 

[JohnHL]

Thank you, JohnHL and thank you, ACEd.

My pistol is from the 81000 - 82000 lot.

I found a Sear Release Lever on Ebay for $7.99. Sound too good to be true to find one so quickly. Please see the picture. Does this one look OK?

Thank you, again.

Dennez, the sear release lever is a fitted part.

That means the new part has an overlength foot (the angled piece sticking out on the bottom) that is carefully reduced in length (by small amounts) and tested until "proper decock timing" is achieved.

"Proper Decock Timing" means the hammer doesn't fall until the end of the firing pin is blocked.

On 2nd and 3rd gen pistols, S&W installed a firing pin block safety in addition to the manual safety.

That means, if your hammer drops before the manual safety blocks the firing pin, the firing pin is still blocked by the firing pin safety.

Redundancy.

The 1st gen models 39 and 59 do NOT have a firing pin block safety so there is NO back-up if the decock timing is early.

The gun WILL fire!

That is also why 39/59 pistols can go off if dropped.

For your's and other's safety, take the time to learn how to properly replace the sear release lever (not difficult, just tedious) or seek to have it professionally installed.

John

 

[Dennez]

Me: Your honor, I did not mean to shoot that man. I just decocked my model 39. 3 times.
The Judge: But, he was shoot with four bullets.
Me: Well I dropped it once too.

 

[Sevens]

Your Honor, I object! The judge presides over the proceedings, he does not refute testimony or offer evidence, that’s the prosecutor’s job.

Hey, while I am objecting and taking part in thread drifts, I gotta say that I don’t like decockers on pistols. Hammers on revolvers pre-date cartridge guns and human gun handlers have learned to safely lower a hammer.

It was a Taurus PT-99AF that was the first handgun I ever owned with a decocking lever. “Heebie jeebies” barely captures the feeling I get when I consider the idea of willfully making a hammer fall for the select purpose of making a loaded handgun a little bit “more safe?” ?!

I do understand the design and the risks. I understand fully how the firing pin lock works on Gen 2/3 and how it is absent from the 39-2 and 59.

Bottom line for me is that the idea that a hammer gets dropped full force over a loaded round -AND- we do this on purpose by design?

Apologies for the rant-drift. I don’t like ‘em.

 

[Green Frog]

I felt a great sense of accomplishment when I learned to decock a 1911 one handed... but I still don’t recommend the practice nor do I do it routinely.

As for my own experience cited above, yes I got lucky but as JohnHL said, I also had the redundancy to help me out. I didn’t mean to mislead, and bow to the superior experience of those others here (including JohnHL especially) in the suggestion that this part whose fitment is more critical with the 39s than their successors, so please ignore my previous, rather smug comment about the one (1) I have installed.

Froggie

 

[Sevens]

Haha I did not find that smug. Experiences are experiences, and have value when shared.

I once had a really oddball problem with a 2nd Gen pistol — the slide would randomly lock open mid-magazine. And it wasn’t the slide lock that was doing it.

I eventually followed it to the disconnector, hard as that might be to believe. Dang thing had a tiny burr on it. That little burr would catch and the disconnector would NOT fall back inside the frame and it would catch the slide and keep it open!

Never seen this before or since on any 1-2-3rd Gen. In fact, I’ve not seen a discussion where anyone else has seen this happen. But it’s possible!

 

[JohnHL]

Sevens, I too was a trifle bemused upon my initial exposure to the hammer drop safety.

But due to the utility and dependability proven over time, I have grudgingly developed for them a Strange love or How I learned to stop worrying and love the dingus.

John

 

[Sevens]

If I have to find something about the S&W decocker that I do like, it’s that I can lower the hammer on a pistol without a magazine because of that OTHER feature I’m not a fan of. However it is a royal nuisance on a Model 52 as this model does not have a decocker.

It’s basically impossible to lower the hammer on a 52/952 without a magazine inserted. This becomes blatantly obnoxious if you have loaded your magazines the night before a range trip.

Also kind of curious as none of the other Performance Center Limited target pistols employ the magazine disconnect safety and neither does the old school Model 745.

S&W seems consistent in their lack of consistency!

 

[Dennez]

Hey Folks,

I just got back on here and did not see your posts until now. From my end I was just joking around about the silly possibility of shooting someone multiple times deliberately and then blaming the gun. The ole drop safety / decocker defense.

I have always been nervous about decockers and safety devices. I never thought about the timing issue. To think I could have replaced the lever and called good only to later put hole where I did not mean to. That's scary and I bet its happened before.

I grew up on wheel guns so I learned the old school way to gently put the hammer down. When I turned 21 the first gun I bought was a Glock 17 and that made sense to me. Sortly there after I bought a Sig P226 and I thought their comment in the manual that the only safe way to decock was to use the decocker was stupid. I never had a decocker before.

I hope whatever I do to the internals that the trigger is unaffected. Without a doubt this 39 has the best DA/SA trigger I have ever used. I was duped by the myth that Sig Sauer had great triggers and especially enthralled by their short reset offering as if they invented short reset. Ha! I have had multiple 226's and 229's and they are not even a nearby runner up to my 54 y/o Smith.

Thank you!
Dennis

 

[JohnHL]

Let not your heart be troubled, Dennis.

Replacing the sear release lever will have NO effect upon the trigger.

John

 

[Dennez]

Finally I received the sear release lever I ordered. Initially sizing it up against the one that was in the gun they looked identical in shape and size with the exception that the old one showed a good bit of ware. I smoothed the sharp edged of the new one with a file; it just seemed like the right thing to do.

Installing the new one was a breeze and now the decocker works perfectly. As far as any timeing issues I cannot see how the gun could ever discharge during the decocking process. That's because as the decocker rotates it shields the firing pin from being struck by the hammer. And for that matter when the decocker is rotated to the safety position the hammer is blocked from contacting the firing pin rendering the gun drop safe. Nonetheless I hold fast to the belief that safeties are mechanical devices that will fail.

Thank you all for your comments, insights and guidance. Without you it would have been impossible for me to have diagnosed the problem. Instead I would have been out money and time using a gunsmith and I would not have learned anything.

Take care my friends.
D

 

[Racer X]

Agree - get new one - they are not expensive - Numrich, Brownells, Midway are good sources for parts. Careful buying used parts. And check prices - saw some used 5906 grips on eBay for $49 - but you can get new from above sources for around $20
Best, ED

Yup. Just got my new 5906 grip from Midway last week. It was either $19 or $20.

 

[Sevens]

And for that matter when the decocker is rotated to the safety position the hammer is blocked from contacting the firing pin rendering the gun drop safe.

Well I like your thought process but in the interest of clarity, “drop safe” isn’t the accurate term here. Indeed, the hammer is blocked from discharging the pistol, even if something catastrophic were to happen to force that hammer to fall, I can agree on that.

However the pistol isn’t drop safe because the firing pin is not locked in place. That was a key addition (improvement?) in the 2nd Generation of upgrades.

Will the mass of the firing pin carry enough energy to unintentionally discharge the pistol if the firearm were dropped? I don’t know and I hope that I never find out first hand. But the 1st Gen pistols should not be considered drop safe, and for that matter, neither then should the 2nd Gen 745 pistol.

Conversely, the 2nd and 3rd Gens are drop safe and do employ a firing pin lock. The design is such that if you dropped one (even with safety OFF and hammer free to make contact!), the firing pin is dead locked in place until the trigger is willfully squeezed.

 

[JohnHL]

Dennis, congratulations on making a repair to your pistol.

It is commendable that you chose to learn and fix it yourself as opposed to taking the easy way out and simply writing a check to someone else.

Your quest for knowledge encourages me to make a few comments on your post, not as criticism, but rather in the interest of edification.

Finally I received the sear release lever I ordered. Initially sizing it up against the one that was in the gun they looked identical in shape and size with the exception that the old one showed a good bit of ware.

The "wear" you noted on the old sear release lever was not wear at all, but rather the file/stone marks on the foot of the lever by the builder/armorer who last installed/timed the old lever.

The wear occurs at the aluminum frame rails as the slide traverses.

I smoothed the sharp edged of the new one with a file; it just seemed like the right thing to do.

It was the "right thing to do" because a new lever foot would have been too long and could have caused decocker timing issues.

Filing/stoning the lever foot is done in increments and tested to determine that timing is correct and the proper amount of the foot has been removed.

Installing the new one was a breeze and now the decocker works perfectly. As far as any timeing issues I cannot see how the gun could ever discharge during the decocking process. That's because as the decocker rotates it shields the firing pin from being struck by the hammer.

If the sear release lever foot is left too long, it is possible for the hammer to fall in the first few degrees of manual safety body rotation, before the firing pin is blocked, resulting in an accidental discharge.

And for that matter when the decocker is rotated to the safety position the hammer is blocked from contacting the firing pin rendering the gun drop safe.

Correct.

The firing pin IS blocked, but only when the safety is ON.

When the safety is off (the way most people carry them in anticipation for the first, double action shot) the firing pin is free to move (on 1st gen pistols) and can strike a primer if the pistol is dropped.

Nonetheless I hold fast to the belief that safeties are mechanical devices that will fail.

Spot on!

The only real safety is the operator.

Thank you all for your comments, insights and guidance. Without you it would have been impossible for me to have diagnosed the problem. Instead I would have been out money and time using a gunsmith and I would not have learned anything.

You're welcome.

And props to you for showing the initiative to tackle your own repair!

Take care my friends.
D

Best of luck to you too, Dennis and good shooting!

John