Just sat down to clean the guns and got to wondering why S&W has a piece of cotton stuffed in the trigger return spring. Anybody know?

I thinks its to increase the weight/tension of the spring.

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MSP - Retired

There are a number of threads on this issue. I am not sure of the material in that spring, but doubt it is cotton.

The fiber or whatever it is insert in the spring is sometimes referred to by me and others as the "tampon" in the trigger spring.

Its purpose is to prevent that spring from shattering or vibrating itself into pieces. It "dampens the harmonics" of the spring. That part was in the trigger spring on the original SIGMA, it carried over into all subsequent re-naming of the SIGMA, such as SWVE, and SD models, etc.

The unfortunate design is also in the M&P, the premier line of service grade pistols now in the S&W catalog.

The problem with that "tampon" is two-fold: (1) it has been known to "disintegrate" when soaked from dip in water to cool a very hot pistol; and, (2) if it is saturated with water, salt water or some other corrosive, the spring itself will prematurely wear from rust. The problem is known, and the "solution" is not a proper spring, but replacement of the spring with the insert every few thousand rounds. I believe S&W recommends to its LE agency customers replacement every 5 years or 5,000 rounds. The manual contains no such advice, at least the last time I looked, so us non-agency customers have to discover this ourselves, and we are simply out-of-luck if that spring shatters during a defense encounter.

In fairness to S&W, the trigger spring on the Glock has been known to shatter as well, though with far less frequency. And, Glock has a replacement option that eliminates the problem completely, and that is the so-called New York trigger spring, which is not a vibrating coil, but which is an extremely strong leaf spring.

The tampon is the one weakness that I think disqualifies the M&P for military or other heavy service. While it is likely never going to be a problem for light use such as American LE officer or agency use, or for ordinary citizen use, the chances of a weapon encountering submersion increase greatly with actual real military or special forces use.

Thus, while I would not get rid of an M&P because of the spring, I would advise keeping a spare on hand just in case. It is good practice to change that spring with its tampon each time you change magazine springs and recoil springs. In addition, avoid getting it wet with anything just the same as you avoid, with any striker fired pistol, getting cleaning solvents or oils in the firing pin channel, as those can drastically slow down the firing pin, resulting in light strikes. Again, same advice for Glock, so no real difference between S&W and Glock on this issue either.

Personally, I wish they would address this issue, but they have not done so in the entire time since the first big magazine article on the SIGMA, which included dunking the piping hot SIGMA into a barrel of water to cool it from the ammo firing torture test. If I recall, that spring shattered once and the author thought it was a fluke, but when it happened again, upon close inspection, those who were present realized that the "tampon" had disappeared, apparently coming apart from being soaked. The article said that an S&W representative was present, if I recall correctly. I wish I still had the article, but I do not. That article probably made the SIGMA dead on arrival. For some reason, no one has mentioned the issue in subsequent articles, but then again, gun magazine articles are mostly press releases disguised as articles these days, and no one wants to upset the advertisers.

And, for all I know, S&W has changed the material from which the insert is made to something else now, but if they have done so, they have not made any public statements on the issue. I wish they would.

Wow...Thanks Shawn. There is so much to learn! By the way, the manual mentions "more frequent" replacements under some conditions (like if you use +P) but I have never found a replacement/maintenence schedule anywhere. Is 5000 rounds a good place to think about new springs? Every two or three years? Thanks for posting an answer (again), I should have searched the threads.

Will S&W sell these springs to us?

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John

Touchy subject - I'm not going there anymore!!!

Yes, or at least they used to. I bought one once. I think it was like $2, but $8 to ship or something like that. Since then I've leaned you can usually pick them up at Speed Shooters Specialties, so added a few to an order.

if you use an Apex kit you typically install it's replacement spring as well...

That foam piece will not be damaged by water. I clean my M&P's in an ultrasonic cleaner filled with a water based solution with no damage. I have been doing this on my 9 and 45 for years.

They each get cleaned once a month based on my IDPA, USPSA, and Steel Challenge schedule.

Not a touchy subject at all, just the plain, unvarnished truth.

I am not sure about S&W's policy on selling parts. I have seen wildly differing accounts on this forum. I do not know why they would not sell springs, but who knows. That said, G&R Tactical sells an M&P Maintenance Package.

S&W M&P Maintenance Package (OUT OF STOCK) at G and R Tactical

That is good to know. I am still curious to know exactly what the material is inside that spring. Shooters on other forums continue to report occasional problems with the "tampon," so I am glad you have not had a problem. Yet.

Shawn,

Your post has to be the most informative post (9/2015) I ever read on this forum. Concerning the M & P series. the trigger springs in my 2.0's appear identical to the 1.0 series so maybe S & W made no change in the spring or spring material ? I searched Wolf if they produce to replacement trigger spring but NOT for duty or civilian use, surprised me. Since you are so knowledgeable any suggestion on source for replacement springs. What is your opinion of stainless replacement springs?

I as well as other M & P shooters would benefit from you recommendation for better quality trigger, extractor and hammer springs.

went to posted http:. the kit didn't come up. a sku/ picture of kit if you have the time to post it. thank you for your info and time.

You can go to Midwest Gun Works and still buy just the trigger spring. Other places may offer the spring as part of the trigger bar.

Since this thread is 7 years old, one has to expect that links may no longer be valid.

The maintenance "package" contains the trigger return spring, 2 mag springs and a recoil assembly. All can be purchased separately.

What's That Packed Inside The Trigger Return Spring?

I’m going to provide a differing perspective.

My department has somewhere around 8,000 M&Ps in service. Our firearm training staff is less than two dozen for over 10,000 armed personnel to include reserves and we train between 13,000 and 15,000 training slots a year on average... most of those involving the use of M&Ps. I’ve been armorer certified on both the original M&P as well as the 2.0 and I oversee our testing and evaluation of various pieces of equipment to include pistol optics, and I basically run our pistol optic program with a couple other instructors.

I say this because it’s important to know the background of who is providing information. What I’m about to say isn’t “what I’ve heard on the internet”. It’s millions of rounds fired (Yes... We order by the millions) by thousands of people over more than a decade of using M&Ps in service.

I switch guns too much and had to turn in my beloved and horribly abused instructor-issue M&P 1.0 at somewhere over 45,000 rounds and for the past couple years have mostly shot Glocks but I’m back in the M&P game for at least a while. My current high round count M&P is probably at around 10,000 rounds. I have fellow instructors who have always used the same pistol that are at well over 100,000 rounds. Parts rarely get changed. That 45K round M&P broke the only recoil spring it had at around 35,000 rounds but was still 100% reliable. I changed it when I discovered it during an inspection after throwing it in water, mud, sand, and spraying salt water on and in it for a couple weeks. (Yep... Sprayed the tampon too...)

I know of maybe one or two department members, to include our crazy-high round-count instructors, who have ever broken a trigger spring. I’ve seen broken recoil springs, broken striker springs, a broken locking block, and a cracked barrel that, when ultimately examined by the armory and S&W, with a confirmed round count of over 120,000 rounds was found to have been fired for many thousands of rounds with a broken recoil spring and basically demolished the entire frame... destroying any accuracy the pistol had... but it still fired... every time.

Oh yea... We have an industrial size ultrasonic cleaner that most of us use for our high-round-count guns when we want to clean them. The frames get dunked on a regular and in some cases constant basis.

I oversee testing and evaluation of optics. We submerge the pistol up to just underneath the optic (so the whole frame) every three magazines and our testing is over 10,000 rounds. That’s in addition to the five intentional 30 second complete submersion during testing.

We have done this twice so far with M&P 2.0s and will be doing it two more times soon to test additional optics so the same pistols will be at 20,000 rounds being dunked every three magazines. The tampons and trigger return springs live on.

In addition to the durability aspect, there’s also the reliability aspect. I have fired M&Ps after being submerged literally hundreds of times and I’ve never seen a malfunction related to the submersion, but I’ve seen my Glock 17 malfunction almost every other round when dunked in a couple puddles during a rain storm... Marine striker cups are a necessary thing for a Glock... Not for an M&P.

Nothing is perfect and I have my issues with the M&P like I do with every pistol... It’s probably why I switch so much. I haven’t found my holy grail. I will say an M&P 2.0 with an Apex barrel gets really close though...

Back to the issue at hand. I’m sure there are people who have had the trigger return spring break. I don’t think the tampon, which is indeed designed to reduce vibration and increase lifespan of the spring, is the cause. I think sometimes stuff happens. Sometimes Glocks break or the pins just decide to go on strike and they walk out of the gun (happened to me). Sometimes Beretta slides hit people in the face (have the injury report from probably a couple decades ago). Sometimes (okay... lots of times) 1911s have malfunctions or breakages (I’ve had hammer struts break, firing pin stops crack, hammer follow, bad slide stops, excessive barrel bump on the link, safeties fail to function, and extractor tension issues... just on my guns, let alone the hundreds of others we have in service).

Could the trigger return spring on an M&P break? Yes. Have they broken at times in the world? Yes. Have. Ever seen or heard through our department of a vibration dampener (tampon) failing or disintegrating. No. Never.

Based on a very large sample size over a long period of time with extreme abuse and very frequent submersion I would say with very high confidence that the trigger return spring is not a concern any more than any other trigger return spring on any other gun.

No one who knows me will accuse me right now of being a fanboy of the M&P. My confessed soulmate is the 1911 and I’ve carried Glocks almost exclusively since mid 2020. If there was a 2nd spot for love behind the 1911 it would be for the Beretta, with which I accomplished some pretty proud things. All that said, I try to be objective and I’ll be damned if the M&P series, to include (grudgingly) the 2.0 isn’t the most reliable pistol I’ve ever seen...

That was a different perspective and I put a lot of credence in the experiences of the law enforcement community. Thank you for posting your experience.

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VCDL, GOA, NRA

Off the subject but its nice to know some else is from Bakersfield!

SOCALDEP,

While I seen/read Glock torture tests done years ago. I have never stumbled across a M & P torture test until now, thank you for taking the time to inform this forum. If you experience other torture tests of M & P's in the future please share the details.

Thank you for your service .......................

Unless there's something I haven't thought of, which is a real possibility, seems like if there's any doubt, it wouldn't be a big deal to dip the spring in some kind of corrosion resistant solution, knock it around on a paper towel to remove any excess and stuff it with some rayon fiber every so often.

Which has many uses and a 100 lifetime supply can be had on Amazon for a song.

Or just stick a piece of some kind of appropriately dense foam rubber in there.


Although I do have a few spare factory return springs on hand. Just in case.

I have no use for non-factory parts. I think the best solution is to replace the factory spring on the maintenance schedule suggested by S&W, which I understand is the same as the recoil spring.

the foam insert is not present in the full size or core versions of the gun. it is found in the "le only" version of my m&p 2.0 compact 3.6 inch


it seems the compact version of the m&p 2.0s have "vestigial" features like the tension spring in the slide stop lever, and the foam insert, whereas the later versions did away with them.

I think I'll just let my hot pistol cool naturally, and avoid the water submerge method.

In the event it takes a falls into the creek, a full detail clean is called for.

My Sigma 40F from way back around 1997 or so has the fuzz in the trigger spring.

Rosewood

Our experience with the M&P40 1.0 matches that of SOCALDEP. The only failure I experienced in 9 years was the takedown lever broke, I discovered it when attempting to clean the pistol after qualification. Since the slide retaining stud was intact, the firearm was still serviceable, but we obviously changed the item. Our pistols also got twice a year ultra sonic cleaning and armorer inspection. Tampons stayed intact.

For those who might be interested, this is the factory suggested LE maintenance schedule. I assume the time suggestion stays with the the additional service items as the round count goes up. FWIW, my personal example got a recoil spring & striker assembly change after about 10 years/????? rounds and had zero malfunctions during that time. Think I changed the trigger return spring at the same time.

S&W M&P SERVICE SCHEDULE

M&P9/40

Every 5K rounds/5 years replace:
Coil pins
Magazine springs and followers
Recoil spring assembly
Slide Stop
Trigger return spring.


Every 10K rounds, replace the additional items:
Striker assembly
Trigger bar assembly

Every 20K rounds, replace the additional items:
Ejector
Locking block
Magazine catch
Striker block, spring and spacer
Takedown lever and retaining wire

M&P45 the same, except the striker replacement interval is at 20K rounds.

No suggested replacement for the extractor only two broken reported to the factory by 2015. There have been two revisions to the extractor since introduction of the M&P line. The first was marked with an "L" for a longer hook, slightly more rake on the hook and a sharper edge.

The latest revision was named the "Phillips" revision, possibly in 2016. Has a P on it.

Hi everybody. I realize this is an older thread, and I apologize for the resurrection.
I have just been acquainted with the "Tampon"
I have a huge pile of guns from 1866 to present in all sorts of sizes, shapes and calibers, and have never came across this until now.
Putting any kind of material inside of a spring just seems like a bad idea to me.
A friend of mine owns a local gun shop and said he bought a Sccy CPX2 9mm and has put well over 1000 rounds through it without any problems. I was in need of a few inexpensive small-ish handguns, so I had him order me a few. The trigger pull was kind of long and stiff and someone told me about the Mcarbo spring kits, so I ordered several and installed them. The trigger pull went under 4#.
We started shooting one of them getting used to it and then it started to misfire. It wouldn't pop the primer. Pull the trigger again and it would fire. On one magazine full it did it 4 times.
I inspected the pistol and found what looked like a cleaning patch had gotten shredded inside of the main spring and was getting packed between the coils. I had to stretch the spring a little and use a punch to push the tampon out. I put it back together and it still had the occasional misfire. Maybe I pulled on the spring too hard trying to get it cleaned out? I looked at the other springs and they all had the tampon in it. I didn't take a picture of the first one before I cleaned it out. One of the others was starting. I'll try posting a picture, it shows the fuzz starting to come out between the coils.
I pulled all the replacement springs out and put the stock springs back and noticed that the Sccy main springs had a strip of black felt in them.
I emailed Mcarbo and he said that S&W started this practice. So I searched here and found this thread.
I think this is a terrible design practice. Shouldn't there be some safer way of dampening the harmonic vibrations?

Attached Images

mcarbo-spring-01.jpg (56.5 KB, 12 views)

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Lar45