Sear deactivation lever (yellow)...why?
 

Found it in my Shield--had to look it up in the manual to figure out what it was. Is the sole purpose of this thing to allow disassembly without pulling the trigger OR does it serve any other, real purpose?
I broke the gun down without pushing it (just pulling the trigger). Is that a problem?

Pulling the trigger is how I've been breaking mine down. I suspect the de-activation lever is just sort of a safety to keep guys from pulling the trigger while they have one in the barrel.

Yep.

I always use the trigger instead of that lever on both my Shield and full-size M&P.

If a round was in the barrel you'd eject it trying to get to the lever to push it down...and the mag has to be out. It seems like it solves itself--go to push lever = empty gun.
That's why I thought it might serve another purpose.

You didn't touch that lever did you?? You do have it right, it's to prevent a accidental discharge when taking down the gun. I read that this was a feature requested by some police departments. I always check the chamber, which would eject a round in itself, but I guess if one uses the lever, like you said, this would be an automatic step in dis-assembly.

Yeah, so if the lever GETS PUSHED, then there was no round or mag in the gun. Remembering to push it is like remembering to take the mag/round out.

I pushed it down to see what it does...gun won't cock with it down...put it back up and plan to never touch it again (same with safety). I just don't like little levers/bars inside my gun, waiting to get bent or whatever. I prefer KISS.

The little lever is there because every year, numerous people prove that removing the magazine and clearing the chamber before field stripping is entirely too complex. Taking "pull the trigger" out of the process for field stripping eliminates the possibility of bad things happening.

It also makes it crystal clear that if you do have an ND (negligent discharge) you didn't follow the manufacturers directions and thereby assume all liability. In some cases, you also violate agency/departmental training and/or regulations putting the idiot in question in more trouble.

Since inserting the magazine flips the widget up, there's really no big deal about it. After cleaning and with slide in battery, insert mag, charge chamber and place in the holster.

The Sear lever, along with the 'No Mag Disconnect' warning is pretty much pandering to the lowest common denominator of gun buyers.

Along those very lines, they kinda messed up with placing that warning on the right side of the slide...
With the majority of people being right handed, if the pistol is in the shooter's right hand, how are right-handers supposed to SEE that warning?
Is that warning just for Lefties? They're the only ones that would see it on a regular basis.
Is this an example of 'Lefty Profiling'? That's not right. :eek: :D

You know, this is funny because I read a lot of comments/complaints from people who don't like having to pull the trigger to field strip a Glock. :p

I guess it just goes to show that no one thing will please everyone...no offense to the OP intended. Good thing we live in America, and have choices and options!

Is it possible that some leo departments request that the firing be disabled when the mag is removed as a saftey if the leo and bad guy are fighting over the weapeon? Therefore, if a spring action added, this would be done. Saving the need for different tooling?

As per the manual you do the (barely) yellow thing for a field strip. So what I'm understanding you can pull the trigger (like a Glock) for the take down with no harm done?

I broke it down 3 or 4 times the trigger pull (ala glock) way. Looking in there I discovered the yellowish thing, and flicked it around trying to figure out what it was...I decided it was the leftovers of a vestigial mag safety without spring.
Someone said trigger pull-breakdowns COULD hurt the firing pin, but they seem to have erased that post. I will continue to ignore the yellow thing until told otherwise. Once you get to it, it's an empty gun anyway.

As a glock guy I'm not a fan of extra parts (more stuff to bend/break--so far, I've only read of one case where the spring holding this over allowed it to move too much and mess things up). I'm also not a fan of wisdom teeth, appendixes, and tailbones.

YES.

The concept of being able to field strip a striker fired pistol without having to pull the trigger first to release the striker was done for a reason.

A certain Federal agency whom I won't name has a had a lot of holes in the walls of their Firearms Training Facility over the years as a result of their issued Glock's needing to have the trigger pulled while field stripping the gun in order to de-cock the striker.

The ability to de-cock the striker w/o pulling the trigger was a huge selling point for LE agency sales.

I have fat fingers. I have found an ink pen works well as a tool to flick the yellow lever during disassembly.

Interesting...
I can understand why such a lever would be advantageous with a Glock (or brand with a similar take down), since one doesn't rack the slide back to field strip it and people could be too lazy to ensure the chamber was clear before take-down.

With the Shield though, the slide does need to locked back (which would extract & eject the chambered round) before one can flip the take-down lever.

If S&W had given the Shield a take-down device like that on the Glock, I could see adding the disconnect lever, but maybe I'm missing how someone could flip the lever on the Shield without racking the slide.

I'm just glad we're able to choose to use the lever, or use the trigger.

There is no such thing as an Accidental Discharge the lever is there to prevent any chance of a Negligent Discharge during take down. As part of my safety routine I always use the lever.

If/when they S&W releases a version with a mag disconnect then it will be a requirement to use the sear deactivation lever to release the slide unless a magazine is inserted prior to pulling the trigger. Needless to say, putting a magazine back in could potentially lead to problems if one inserts a loaded magazine.

My new Shield has a magazine disconnect and I have to release the seer deactivation lever to field strip it. No other way that I can see. Not wild about it since I'm used to my Glock but I suppose I can live with it.

Personally, I like the lever. Keeps the stripping sequence consistent and defined. Rack the slide, flip the takedown lever, drop the mag, flip the sear diconnect (with pinky), release the slide. No WAY for an AD.

Put mag in, pull trigger, take mag out. Simple, asking for trouble, but simple

The take down lever was requested by a department that used to issue glocks and now has many holes in the ready room.

It can be removed and replaced with a spacer or spring -- just like the mag disconnect can be removed and replaced (there is a OEM part, a spring, that fits in the gap -- although I ran mine for a while with a home-made spring after I took out the mag safety).

But... like others here... I have come to prefer using the yellow lever, even though it is not "necessary." You don't have to take out the pin from the heel of the butt to activate it -- S&W includes that instruction to show that you will always be able to do it with tools at hand -- because a pen will do.

And that step AUTOMATICALLY MEANS the chamber will be empty. What's not to like?

I helped clean up an incident after someone shot and killed himself with a Browning HP after mistakenly chambering a round and then "demonstrating" it was empty. And he was an experienced weapons sergeant -- who simply made a mental mistake. Using the yellow lever ENSURES the chamber is empty.

I like the little yellow lever.

I was RSO for an officer who had an issue with a bad department reload that was improperly resized.

Which meant that the live round would not go fully into battery and would not extract. I wasn't willing to try firing the round since I had no confidence it was loaded properly.

The solution was to use a tool to disengage the extractor, then rack the slide back and use the yellow lever to enable disassembly of the pistol without firing the round. I could then use a squib rod on the removed barrel to hammer the (still unfired) round out.

For me, the lever saved the day.

I also have the problem where the slide will sometimes not release when using the yellow sear deactivation lever. I have the newer version of this lever, and no magazine safety. I have searched many forums and did not find an answer. I may have figured this out.

Take the slide off. Move the yellow lever up and down. You will see it moving the “firing pin release lever” up and down. Now pull the trigger. You will see that the firing pin release lever now moves “further”. What is happening, is that the yellow lever is not moving the firing pin release lever far enough, and the “slide” is catching on the firing pin release lever. (It doesn’t help to try and push the yellow lever further than it wants to easily go, and can result in it getting stuck, as some people have mentioned.)

I have found that if I pull up on the back of the slide, while it slides forward, it will usually then clear the firing pin release lever.

I think this is a design flaw on an otherwise very fine gun.
I think more people will have this problem as the sear activation lever wears on its pivot pin. Over time it will get “sloppy” and push the firing pin release lever even less.
I am disappointed that S&W does not appear to have addressed this problem yet.

Using the trigger to break down a gun violates one of the cardinal rules of gun safety.


1) All guns are always loaded.
2) Never let the muzzle cover anything you are not willing to destroy. (see rule #1)
3) Keep your finger off the trigger until your sights are on the target. (see rule #1)
4) Be sure of your target and what is beyond it. (see rule #1)

I am not sure what the point of your post was Bluejax01; when you say:

"Using the trigger to break down a gun violates one of the cardinal rules of gun safety."

First I was not advocating using the trigger. I was explaining why some people are having trouble using the sear activation lever.

Secondly, I find it hard to understand your position that using the trigger would break a "cardinal rule", when this is the only method available on a lot of guns.

I did just realize the original poster was referring to the Shield model. Mine is the M&P model. They may not have the same problem.

I was responding to the poster who said to use the trigger.

And most guns do not require that the trigger be pulled to remove the slide. Only a notable few. And I didn't write the rules, I'm simply passing on that which millions of us have learned over half a century.

I did notice that you have posted 5 times on the forum and 4 were resurrecting old threads to repeat your original post verbatim 4 times. If you think it a design flaw, you will get a more comprehensive answer by writing to S&W once.

Flipping the lever came naturally for me, since I had read the manual through several times while waiting to pick up my pistol, and that was the procedure outlined there. It never occurred to me to use the trigger, and only discovered that it was possible to field strip by pulling the trigger to release the slide when I was told about it by another shooter. I always carry a small screwdriver with a pen clip in my shirt pocket for just this purpose (my fat fingers don't fit into the magwell very easily).

Yea I posted in several forums because I could see many people were having the same problem as me. And no one knew what the heck was going on. I wanted to reach as many people as possible with the answer. I have no intention of contacting S&W. I have already figured out the problem and can resolve it on my own. Again it annoys me that no one at S&W has addressed this problem for the many others out there who are still most likely having this problem, as it could indeed be a safety issue.

I dont know man, I a noobie. But it is my understanding that the "sear deactivation lever" has been out less than a decade, not half a century. And further, I disagree about the "notable few". Again, most handguns were designed and made without this special release lever that has only been implemented in the last few years.

This won't work. Once the trigger has been pulled, you must pull the slide back far enough to move the take down lever. This will reset the action and negate the pulling of the trigger and you'll still have to use the yellow lever.

It is not a problem as long as the pistol is NOT LOADED. :)

I never, ever post in forums. I made an exception this time because I thought I could help others.

In my zeal, I posted in the wrong forum. I apologize for that.

I then managed to get sidetracked into discussing matters totally unrelated to the original post. I apologize for that also.

Hey. no big deal and no need to apologize.

Carry on sir.

I was assuming (yes I know) the take down lever had been moved already.

Pull slide back
Rotate take down lever
ease slide forward
insert mag (you may have to pull the slide back far enough to ensure the disconnector is aligned)
Pull trigger
remove slide.

Better?

Yep, that will work. :D

Well technically..... :p

You have to remove the magazine after you pull the trigger and before you remove the slide. :D

Just sayin'. I know someone was gonna jump on ya and say your way doesn't work, so I figured I better clarify just a touch...

And for the record, I've stuck a pencil in the mag well and held the mag safety back so I could pull the trigger to release the slide. Why? Because I could! :D

Me personally, I just buy the one without the mag safety. A lot easier to make the RSO who wants to hear a CLICK at an IDPA match happy then having to carry and empty mag.

Nope. I just tried it and you don't have to remove the mag to take the slide off.

Here's what I did:
Insert empty mag.
Lock slide back.
Move take down lever.
Ease slide forward.
Pull trigger.
Remove slide.

At least it works for me.

I have the sear deactivation lever, but I cannot disassemble by pulling the trigger, is that normal??

I like the yellow lever, it's just another safety feature. I was taught that you can never be too safe with firearms. You really shouldn't need the lever if you follow safe gun handling. I was always told to double and triple check to make sure the weapon is empty. It always amazes me when I see people being so reckless with firearms.

I dig it too.... we have a very good SWAT officer here in town that had a ND with his Glock 22 duty gun one night (he was distracted while putting the gun on the bench, but after removing mag). He came back short stroked to get the takedown lever set, and put one through his reloading bench into his leg. All is well, and he recovered fully, but his mistake taught me to FULLY lock back the slide and VISUALLY check the chamber/magwell.... I am sure there are some high speed guys here that feel thats silly, but it is the only foolproof way with a gun that must have the trigger tripped....

OP-- breakdown while pulling the trigger may damage your gun... after 50K cycles or so.... :D:D its like dry firing.... you are not going to do it enough to see significant wear....

It is if you have a model that has a magazine safety feature.

Use the sear deactivation lever as it was designed and intended.

The sear deactivation lever feature was designed in the gun after receiving input from LE during early R&D. Proper use of it requires the user/owner lock back the slide, which provides for an opportunity to make sure the user/owner has done a safety inspection to make sure the chamber is clear and no magazine remains in the pistol.

The XD uses another method to help let the user/owner confirm the gun is clear, and the older Ruger P-series used another way. I remember the first time I realized I had to lock open the slide on my P90, and push the ejector plate forward in order to field-strip the pistol. It seemed odd at first, and an unnecessary additional moment's work, but it did make for an extra step to ensure the gun could be checked for having been properly cleared.

Lots of folks like to say that firearms safety should primarily remain between the ears of the owner/user, but in the real world people are often lazy, inattentive, complacent, etc ... and it doesn't hurt anything to add in a minor manipulative step for field-stripping to help make sure someone hasn't set themselves up for a ND.

BTW, the original deactivation lever was curved/folded over, and it was changed to having a straight tip. The reason? Cops are still lazy and sometimes inattentive.

It was found that if the curved lever was left in the upright position during reassembly, the slide's pick-up rail would hit it as the slide was reinstalled. This stopped reassembly and could potentially result in damage to the lever if the user tried to force things. The revised lever puts the tip out of the way of the pick-up rail if it's left in the upright position.

It never hurts to remember that issued users of regular equipment - which means guns for cops - really does need to be kept simple and as foolproof as possible. ;)

It's an insult to have a sear deactivation lever designed into the gun ... which sometimes seems to be how some folks seem to look at it. ;)

The sear deactivation lever is one of the many reasons I like the M&P over the Glock. It just plain bugs me to have to pull a trigger to take down a pistol. Bill

Absolutely correct. In the many years I have been handling guns it gradually has occurred to me that I am all for about anything I can do to make gun handling safer and obviate the potentially awful effect of a "momentary mental lapse." Those lapses do happen, and if they happen at the wrong time...

For Heaven's sake, why wouldn't you use the yellow lever? If you are in that big of a hurry, I'd say you are well on your way to an accident. JMHO. :)

Do you ever take the gun down without an empty mag? I do sometimes so my procedure goes: Take out magazine, rack slide 2 times to insure the chamber is empty (if a round was in there, it would eject) then on the third time I manually engage the slide stop, rotate the take down lever, flip the sear disconnect, take the slide off.

Why is there a yellow lever? One word: Marketing...

In our lawsuit happy world it is easy to sell something which is "safer" than the other guys. Never mind it does not make it any safer and adds complexity to the design thus departing from the KISS principle. It is the same reason some guns have mag disconnects and warnings etched on the slide. It HAS to make it safer, right? I will skip the discussion on the right hand only thumb safety on my Shield which I and many others don't use.

The fix for negligent discharges isn't some gimmick, but rather training. I can go buy a piano, but it doesn't mean I can play it... Just like I can purchase a gun, but it doesn't mean I can run it safely.

For my guns, S&W can keep the extra parts for the yellow lever & thumb safety. They can even eliminate the slide etching step. It will make my guns simpler and maybe even cheaper. If they need I will sign a "I will not sue you" form if it will make their lawyers happy.

All of the YMMV & IMHO tags apply...

Edmo

Even the best-trained, most-experienced, most-cautious people in the world are still... people. In the world.

People make mistakes. There has never been designed a zero-error human.

The world conspires to distract even the most attentive person.

If adequate training was all that is necessary to avoid NDs, guns would not have trigger guards. After all, if you're "careful enough," the trigger would simply never get caught on anything but an intentional finger.

Of course, the definition of 'careful enough' is circular - - you're only 'careful enough' prior to your next accident. At which point you clearly weren't.

The takedown lever is an elegant solution to human error that is all too common even among the experienced, and thus far I have seen no supported 'downside' to it. Have yet to see a case where malfunction of the takedown lever prevented intentional firing of the weapon or caused unintentional firing.

But you'll never catch me dangling my precious pinky down inside the chamber; I like it too much. I have way too good an imagination of what it would be like to have the chamber slap shut on it in case of 'mistake.'

Luckily, many common gun-cleaning tools will reach it just fine, including a Q-tip.

Murphy was an optimist.

This was nicely written.

I can tell you from experience that it will not cut your pinky off. However, it does hurt. Still, with your pinky in there, the slide doesn't have far to move and doesn't build much momentum. You'll do more damage hitting your thumb with a hammer than an M&P slide closing on your pinky.

Even so, the advice to use a tool is the very embodiment of wisdom and should be followed.

The orange-peeler on your Swiss Army knife reaches the lever just fine, as will almost any ordinary ballpoint pen.

There may be some point to the eternal magazine-safety debate but fretting over this yellow lever seems silly. Just use it. :)

That yellow thingy is not that useless after all.
I was playing with tuning trigger bar and sear housing part,
and figured out there might be a situation when this lever is the only way to remove the slide.

Since I'm a former Glock owner I will sometimes pull the trigger to get the slide off. Lately I usually use the sear deactivation lever unless I don't have anything handy to push the lever down. There's always the frame tool but that's a whole different story. I always check, double check & triple check my chamber & mag well to make sure that the M&Ps are totally & completely empty before pulling the trigger for a dry fire.