Hello All. I'm having a problem with S&W repair service. The slide on my M&P 9mm won't lock open after the final round has been fired. It's been sent back twice for the same problem and both times, they keep it for a month and send it back with the repair tech's notation "Can't duplicate customer complaint." Customer service tells me they fired 5 magazines on the range and never had a failure. I fire it and it fails every time. Regardless of brand of ammo or grain. I'm not sure what they are firing through it for testing, but it's now a 'I said/they said' issue that I can't get resolved.

I have a video shot yesterday at the range where the problem is evident. I've sent them the link, but don't know if they've even bothered looking at it.


Any suggestions on how to deal with these folks would be appreciated.

Are you absolutely sure you are not pushing down on the slide lock? Hard to tell from the video but it looks like your support hand index finger is wrapped around the front of the trigger guard which can throw of your whole grip.

No offense intended, just usually the first thing to check. I do that sometimes when shooting me Sigs if I haven't shot them for ahwile and need to readjust my grip.

Thanks for the suggestion, but I doubt that’s the cause. I say that because if I shoot single hand or opposite hand I get the same result.

Do you send in your mags with it? The odds of all of your mags being defective is slim, but I guess it could be possible.

Suggestion-- go buy a box of Nato 9mm or some +p ammo then put one of those in the mag before loading with your regular ammo. (that will put a very strong round as last round fired before last round lock-up)

If it STILL won't lock back on last round & you are darn (positive) sure that you are not contacting the slide stop with your hand or finger then you have an issue that S&W needs to address.

How about having someone else shoot it just to be 100% certain?

As already mentioned, check your mags. I've had "bad" mags that were actually because the inside of the mag was gummed up, so that the follower did not push up evenly / firmly against the slide lock.

In an HK I had a follower literally wear out.

If you sent the gun back without the mags involved, they tested with theirs.

AMMO. not hot enough or too hot.
Lube it up and shoot a few brands of ammo
Especially if pistol is new.

Yes, this. The easiest way to diagnose is to try different ammo and have someone else shoot it ( with two different mags.). If it still does it, then it's 100% the gun /mags.

Failing getting someone else to try it, shoot the gun one hand, unsupported. Not quite teh same but the next best thing.

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Dave

I was thinking this same thing. If S&W can't replicate it, then it has to be something on your side.

So either it's the bargain ammo you are using, you grip technique (limp wristing/engaging slide stop), or your mags.

Since it doesn't look like you're limp wristing it, and you're sure you're not engaging the slide stop, and assuming all your mags aren't defective, then it has to be the ammo.

Almost all instances of failure to lock back have been ammo related in my experience. I would find a box of Winchester NATO rounds, Speer Lawman rounds, or a +P type and try it. That should fix it.

However, if that is the fix, then perhaps S&W put too strong of recoil spring in it. When the Beretta PX4 compact first came out in 2011, they had NATO strength springs in them that were for the Euro market. Bargain ammo would not even cycle properly for reliable fire, let alone lock back at the end. I could only get the rounds mentioned above to function properly until the spring got broken in (1000rds), and by that time Beretta issued a replacement spring that would work with USA budget ammo. You would think if it was a stiff spring though, then it would have other cycling problems too like my PX4.

So you got different ammo to try, and letting someone else shoot it never hurts either.

I would move the gun along and get another one.......you are never going to be pleased with it.

I've had this problem with my M&P 40 1.0. It would happen every time. Problem solved by changing my grip

I always suspect the magazines first. I also have had shooter error cause premature slide lock (not your problem). It took me a while to accept that shooter error was a problem as I have a long history of pistol shooting. I finally accepted that a different make of gun could make a grip I've used for decades could be a problem with that specific firearm.

ED: If it's an FS 9, which it looks like; It makes no difference. It has a slide lock on either side!
The quickest way to find out is have someone else shoot the DT!

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It's The Carbonaro Effect!

2 words:
change ammo

I have no reason to doubt S&W. What would be the reason for them to do that. I have no doubt about your statements even if I had not seen the video. To me that means the problem is to be found in the variables between what you fire and what they fire. Find out what they test shoot with and try some. If the gun works OK you have an ammo problem. I doubt the magazine is an issue because you have the same problem with all of them. Really sounds like the ammo to me.

Life's too short to keep aggravating yourself with this.

Ditch the pistol one way or another and buy something else.

I have nowhere near the experience many on here do, but can say that I've put nearly 2k rounds thru my full size 9, another 1k+ thru a PC Shield in 9 and same amount thru a compact 9.
All I've ever used is 115fmj, all brand name and esp in the full size probably half's been Blazer Brass (also Rem UMC and Herters).

Never had an issue with a slide not locking back. So based on my time with my MP's I'd say ammo may not be the cause. But i realize not all guns are the same....

Any chance the RSA could affect the OP's issue? Just a thought as I believe some with Shields had a similar problem until they replaced their recoil springs.

Frustrating issue.

What we can't see with your video is WHERE your thumbs rest when you're firing. A video from the other side might be interesting.

If someone else shoots the gun, and there's NO PROBLEM, the video of the thumb positions might reveal what's going on.

I watched your video a couple of times, and it looks like you have to grab and pull the empty magazine out of the gun. in other words, it looks like the empty magazine won't drop free.

if this is indeed the case, the problem is that the slide stop tab is overriding the magazine follower and slipping down the side. The solution is to replace the magazine follower. I understand that S&W has redesigned the 9mm followers for this reason; perhaps they would send you a couple of the new followers to try.

Also, there are a couple of videos on Youtube that describe this problem. Google something like "Smith and Wesson M&P magazine follower malfunctions" and see if this fits your situation.

Some of the repair folks may not be the brightest stars in the constellation... but that's for another discussion...

I had the exact same problem with mine. I turned mine over to our local gunsmith for analysis and repair. After two weeks I called and received the verdict. The comment came back; "Stop buying you ammunition at Wal-Mart'
That was exactly the problem !

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'I know nothing'.. Sgt. Shultz

The first time I had this problem, they suggested I send the gun and the mags. They replaced the mags with new ones but made no made no mention of finding any problem. This time all they wanted was the gun. From the feedback on here, the problem may be the ammo I'm using. The range ammo is 115 grain, but so is the Hornady defense ammo I use for carry. So I will try some higher grain ammo and see if that solves the problem. If it does, it may mean S&W uses a stronger than usual return spring that 115 grain ammo can't completely compress. I'm pretty sure my hands are not impeding the process.

Actually, that's not the case. The mag release button works fine. I press it. the mag falls. I just don't like letting them hit the ground at this range. Very sandy soil.

Well if you're not riding the slide stop, which was probably the first thing you checked and the empties are poppin' out with authoritah as they appear to in the video and the slide is locking back when racked manually and the S&W guys can't duplicate it...this is a mystery!

I'd try some +P stuff just to see and I'd check the slide stop to make sure it moves freely without any hitches in its movement from burrs and such. Another thing I'd look at is does the magazine spring have any difficulty overcoming the strength of the slide stop spring when you've got the slide off the frame, If the follower has just barely enough umph to raise the slide stop, maybe during firing, it doesn't move the slide stop up into its notch fast enough to catch the slide, while when you manually cycle it has time to move up. I could see how a manufacturing defect could make the spring put too much pressure on the slide stop.

Thanks. I'll try that tomorrow, along with some 147 grain ammo. But I'll do the hand thing before changing ammo. I change them both, I'll never know the culprit.

One thing I noticed was that you were easily able to use the slode STOP as a release. On my shield 9mm I cannot with two thumbs pushing with all my might able to get the slide to release. I MUST "slingshot" the slide.

This makes me wonder if the slide stop is not proper or has been modified to allow the stop to be used easily as a release.

I do not have experience of many here. But I watched in amazement the video at the ease you were able to release the slide. NO WAY could I do that with my gun. And I have used blazer brass 115 almost exclusively with not a single hiccup.

When you rack the slide manually on an empty mag, does the slide lock open?

I have 5 M&P's one being a Shield 40 and one a M2.0, the rest M1.0's and with all 5 of them I can release the slide with the Slide Stop using one thumb, however, they were hard at first.

This would be a good test. If the slide locked back, the lock and mag are probably good, pointing to ammo strength, or shooter technique. If it didn't lock back after inserting an empty mag and racking the slide, that would be slide stop, or mag problem. Please test, and let us know.

Was looking at the video again and noticed that you were using 10 round mags. I think I read that there were some problems with the 10 round limited-by-statute mags, maybe saw it on Calguns.

Something about the springs getting damaged because the designers didn't leave enough room because they were afraid someone could cram an 11th round in and make it illegal or something.

The guys from CA, NJ, NY and MA would probably know more.

In his video, the OP was locking back the slide on an already empty mag.

I had the same problem until my son pointed out that my grip was not correct. He called it "limp wristing". Showed me the correct grip and bingo, problem solved! I hope the problem is that simple for you and wish you success in correcting it.

It may not be the perfect solution... There was no 'aha!' moment and a screw was turned or a burr filed down or the discovery of a broken part, but changing from 115 grain American Eagle ammo to Aguila 124 grain 9mm Luger definitely fixed it. 500 rounds fired thru three mags loaded with 5 rounds 33 times and not a single slide failure. I upgraded my carry defense ammo from the 115 grain Hornady Critical Defense to 135 grain Hornady Critical Duty flexlock, and I'm pretty sure my slide failures are over.

So I can put this to bed, but thank you to all who offered suggestions. Some I had never considered, such as hand placement. I was careful to check that today as I started my experiment. Thank again for all the help.

I looked at the video again and I couldn't tell if he was manually pushing up on the slide lock each time he locked the slide back or if the follower was doing it.

That would be good to know. If he had to push up on the slide lock with his thumb, he could just take the slide off and put a magazine in to see what's going on.

I’m guessing the reason your folks couldn’t duplicate my complaint was the ammunition you use to test. All my gun failures came while shooting 115 grain American Eagle or Blazer Brass target ammo.

When I changed over to 124 grain Aguila 9mm Luger, the problem went away. I fired 500 rounds thru 3 magazines loaded with 5 rounds each. That’s about 33 times and I never had a single failure. That’s not to say it’s a perfect solution, as I think any S&W firearm should function properly with any ammo as long as it’s industry standard, and not be restricted to a minimum grain load. If it DOES have a minimum grain bullet load it should specify that clearly and in very large letters so the consumer doesn’t have these kinds of problems. I was beginning to suspect the gun had the return spring of an M&P 40 rather than the 9, but the spring is blue as all the 9s are.

I’m not completely happy with the result or the solution. I own several S&W pistols from the Performance Center 1911 45 to the M&P Shield 9mm to the M&P 40 and none of them have ever done this. So you might ask somebody in tech support or repair ‘why’. Rather than just right it off as “Can’t duplicate customer complaint” and move on to the next job, don’t just assume the customer is an idiot. Just because your folks can’t duplicate it, doesn’t make the complaint bogus. Ask yourselves ‘why’ can’t we duplicate it? What’s the customer doing that would make it fail? You bench test the gun under ideal conditions. Maybe the customer has positioned his hands in such a way as to put pressure on the slide stop and it’s keeping the slide from locking. Maybe it is the ammo, but if it is an ammo problem, doesn’t that make it a gun problem as well? Isn’t the gun supposed to function with 115 grain 9mm bullets? And if it does not, why not?

S&W really needs to do a better job at diagnosing the problems they are faced with. “Can’t duplicate customer complaint” is an easy way out and really does a disservice to Smith & Wesson and the customer who puts his trust in your products.

I agree, it should function with 115gr practice ammo because that is probably 90+% of what's actually fired through these guns. The service department should keep a supply of mild stuff to test for problems like this one.

I wouldn't be surprised if it started working with the light rounds as the recoil assy. relaxes a bit through use.

I bet with some use it will loosen up and work as intended with 115g. 115g is pretty notorious for causing issues, especially when used in a new gun. I have had enough problems (even in Glocks) to use 124g now for the first few hundred rounds to break it in.

Let somebody else shoot it . . .

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Wisdom comes thru fear . . .

Muss is right...I would've handed it off to someone else to shoot on Day One of the problem. But glad the situation is resolved.

I once dealt with a dealer service rep about an intermittent issue I was having with a vehicle that I bought new but was then just slightly out of warranty. Maddening problem, no rhyme or reason as to when it manifested. Problem wasn't evident on the rack in the shop. I told the service rep that it was full of fuel, and the repair tech just needed to hit the road until the problem showed up so he could figure it out. I got told real quick that A: His tech didn't have time for that and B: If his tech had time for it, I couldn't afford it. Fair enough. Traded it at that dealer the next week . . .

The only real way to truly and validly duplicate the customer complaint is for you to stand in front of the repair fella's at the range with your ammo and have them watch you fire it. The question back to you is "How much do you want to pay?" And by how much, I mean up front, so that the unlimited warranty would include travel for the factory to you or you to the factory to diagnose the problem, or how much for the individual repair for the same service? I'm betting you'd balk.

You don't get to fire the ammo you want in every pistol just because you want to fire it. Some pistols are so notoriously picky that the owner's manual has been edited to rule out certain types and brands. Others just have a reputation for not being reliable with certain ammo, and that information is out there in the digital discussion world. Others just have individual problems with certain brands, thus it's up to you figure that out and avoid them.

If you ain't happy, sell it and move on . . .

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Wisdom comes thru fear . . .

I am in almost lock step with you on this issue, right down to wondering if I had the wrong recoil spring also. Same gun, 5" M&P 2.0. Waaay too many jams out of the first 5-6 magazines (actually after the first shot), brass landing on my face and forearms, and failure to lock the slide back maybe 2/3 of the time. Just bought it before 9/30, fired it Wednesday.
Now, I have owned and traded and/or shot as rentals or friends guns just about every currently manufactured 15-18 shot 9mm pistol, and never had this occur to the extent it did for me with this gun. IMHO it's likely these guns are way oversprung, as the OP is correct, it should function with 115 gr ammo. Maybe the brass doesn't sail into the next zip code, but the gun functions. When I see a deal for Federal 115 grain 9mm at a gun store, $175 for 1000 rounds, I jump on it, and shouldn't have to worry if it will function at an 80% rate in my M&P. It cycles 100% through a SIG MPX and 100% through a P320, and they work just as well with +P.
Even when I was familiarizing myself with the weapon, it struck me that the slide was hard to rack, for a 9mm. It's more like my Colt USMC M45A1 than a polymer 9mm.
I called S&W merely to ask about another RSA, and the rep listened and said I should return it, that too many negative things are in play. Stay tuned. And I don't intend to hijack the thread, merely add to it, or run along side.
Anyway, just my log on the fire.

Yup, 'zactly what I (and others) were thinking. Could this be a limp wristing issue?

That's about the reality of it, and very logical viewpoint of things.

Since it was ammo related like many suspected, then the gun SHOULD break in the more you shoot it and eventually you will be able to shoot all the bargain ammo. Just like PX4.

They recommended like 500-800rds of premium ammo through the PX4 in order to relax the NATO spring they initially shipped with. I got to about the 800rd count before Beretta issued a replacement spring, but even at that point budget ammo still wasn't 100% but better than it was at first.

Now, I just keep the NATO spring in it because I carry 124gr +P and shoot NATO level reloads for practice. If I want to shoot cheap stuff, I swap the springs out.

Give it time and your gun should eat anything reliably. Just sucks you have to go through that process. Every gun is different though, even like models.

I hate to admit it, but I didn't watch your video at first. With the weak ejection, I might have noticed that the recoil spring was heavy. I might have suggested a Wolff spring pack, so you can shoot all range weights of bullets in your pistol and have the slide lock back. WOLFF SMITH & WESSON M&P RECOIL SPRINGS | Brownells

It's interesting to note that Wolff says the 16 lb recoil spring is standard for 9mm, .40 S&W and .357 SIG.
Anyone see a problem with that?

Not if you are a company trying to streamline your parts inventory. Any 9mm pistol today should function with all medium priced practice ammo. If you are going to give the pistol a steady diet of +P or +P+ or NATO ammo, then opt for a more powerful spring to prevent battering. My little Kahr CM9, Beretta 92FS, Sig P320 and even my Marlin Camp 9, all function with 115 gr. fmj ball, as well, as my stouter "carry loads". I'm a big S&W fan, but more and more, it appears to me that cost cutting measures at the company are resulting in more and more customer dissatisfaction.

Shared (common weight) recoil springs are seen with a number of guns. Why? With many guns, the slide is made heavier to control velocity, rather than using a heavier spring.

Glock does this with most of their guns that share a frame -- and because most slides are generally different anyway when the caliber goes up [if only due to a larger diameter barrel], it allows one more part [recoil spring assembly] to be shared by several models.
.

Have you weighed a Glock 19 and 23 slide?

I had to send my model 41 back three times before S&W agreed it couldn't repaired; I was sent a new one. I also sent the new one back twice before to have it repaired. I received the same form letter "We could not duplicate the customer's complaint."

I'm not convinced that S&W follows this practice. Why would the RSA be painted blue if it serviced 3 calibers? To differentiate it from the .45?
It also seems more sensible to juggle $3 springs rather than do more milling or less on a slide to achieve a desired weight.
Glock mills out the slide on the G34 to keep it the same weight as the G17, not sure if they tweak ALL their slides.
Not being argumentative.