Interesting articles published by MSW.

Update: It was mentioned that the links were not working so I'm also posting the text from the articles.

Slide Stop Updates:
M&P Production Updates: Slide Stops | Modern Service Weapons
S&W Slide Stop.jpg
The S&W M&P pistol has undergone a great deal of evolution since its introduction in 2006. In a previous installment, I discussed the recent barrel changes, which improve overall performance with different ammunition types. One of the weakest points of the M&P that shooters really disliked was the lack of a perceptible trigger reset. I do not “shoot to reset” in that I do not hunt for the click prior to pressing the trigger to the rear, and I actually did not realize there was no tactile reset until someone told me. Regardless of your personal preference, Smith has listened to customers and has made a change that gives the M&P an extremely tactile reset sensation.
The first wave fix was around 2012 production, where a new “tactical” trigger bar was introduced. This did improve reset somewhat compared to original production guns, but the 2013 production guns now feature a new slide stop (pictured top right) with a pronounced flare to push the trigger bar back into reset. When the trigger is released to move forward, you feel a distinct click – both audible and tactile – when the trigger bar snaps past the slide stop and resets.
A common question we get is “when exactly did this change happen?” These changes are typically referred to as “rolling changes,” meaning that as new parts are phased in as old parts are depleted. It is therefore quite difficult to nail down the exact date stamp of guns where this came about. The latest guns to hit the office here in April/May all have the new slide stop setup.

Source: Modern Service Weapons M&P Production Updates: Slide Stops | Modern Service Weapons
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This one is on sear updates..

M&P Production Updates: The Sear | Modern Service Weapons
S&W Sear.jpg
From TOP: MIM sear, current production sear, Performance Center sear.

In my last few installments, I looked at the production upgrades to the M&P barrels and slide stops. The next big area of improvement is the sear. The newest guns received at our office in late spring of this year have all been outfitted with the new sear, which is a machined part with a few geometry changes.
The original M&P sear was a MIM part, and actually worked pretty well and was even able to accept hand work to hold a trigger job. A common issue with them was that the striker engagement surface often had some minor molding artifacts which affected the trigger pull. This would typically wear in after some use, or could be stoned smooth during a trigger job. The S&W Performance Center introduced their own machined sear which they used in their custom guns and trigger work, and the machined steel surfaces provided an excellent canvas for further refinement.
In the above photo, the oblong protrusion seen at the top right of each sear is the camming surface which interfaces with the “candy cane” sear cam loop on the trigger bar. The shape and angle of this protrusion control where in your trigger movement that the sear actually frees the striker and fires the gun. You can see that the new production and Performance Center sears both have modified cam geometry, which helps reduce overtravel.
So let’s cut through the egghead gunsmith talk and get to the meat of it. What does this new sear mean for the shooter? With some small improvements to the forming of the new trigger bars, the improved slide stop, and this new sear, M&P shooters will get an out of the box trigger pull that has tactile reset, a smoother take-up than older samples, and a cleaner more consistent break. In conjunction with the new 1:10 twist barrels, the new M&P’s are a very solid out of the box modern service pistol.

Source: Modern Service Weapons M&P Production Updates: The Sear | Modern Service Weapons

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This one is on barrels..

Pic of the Day: New Production M&P Barrel | Modern Service Weapons
S&W Barrel.jpg
The S&W M&P barrels have been one of the main weak points of the gun, as the original barrels with the 1:18.75″ twist were often quite ammunition sensitive, shooting some bullet weights better than others. The second generation of barrels changed the transition geometry between the chamber and barrel for improved durability. This apparent third generation of barrels now has a faster twist, and appears to be approximately 1:10, similar to what CZ and Glock use. In a limited survey of 10 new production full size 9mm M&Ps from this spring, the guns all included this barrel. Initial test firing with 115, 124, and 147 grain ammunition seems to show that these new barrels now provide Glock-like performance and accuracy with the various weights, not showing a preference for any one weight. It is still too early to provide a sweeping endorsement, but this initial testing is quite positive.
Let us know if your barrel has different markings, and when it was produced

Source: Modern Service Weapons Pic of the Day: New Production M&P Barrel | Modern Service Weapons




JFR

I agree with what he says about the tactile reset. Not a must for me, but I know nothing else.

I know some of the youtubers Hickok45 or Colin Noir who like the reset is a common complaint.

Very interesting!
It's good to see that S&W is really fine tuning their products.

Interesting read. Thanks for posting the links,JFR.

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Former USN, Retired US Army

Send an email. Show them a link to the article and ask them if they could furnish you one with the pronounced trigger reset as shown in the picture.

The question I am wondering... how hard is it to swap mine out...

I may be mistaken but I think that it's been mentioned before if you send in yours for something they replace parts with newer/revised versions.

I'm sure someone can chime in with an experience or two.

I think you would find S&W will not bring a gun up to current standards, if you send it in for warranty issues. If you send it in for a mag drop, they are not likely to tear the gun apart and replace the trigger bar and sear. However if you send the gun in for a sear or trigger bar issue, they would likely replace both with the newest parts. Their only obligation is to make sure the gun is returned to the customer in the same condition, as it was originally sold.

Bob

How do you know which version you have as mine is like this:
Has old type Slide stop, the Sear has a circle/dot on face of it and my barrel has the divot/dot(not as pronounced as your picture, more like a small dot) on the bottom of it. and I bought mine of Feb of this year.

Thanks JFR. Excellent information.

__________________
Freedom isn't free.

Not really sure on this one. The barrel on my FS.40 actually has two dimples on it. My shield has one (I think). So that being said it seems like the FS has been through two revisions.

JFR

I don't always consider a production update an improvement. Sometimes it's a cost saving measure. Look at Sig. Many of the FCG parts that used to be milled, or forged, are now cast, metal injection molded, or even plastic. Look at the PTR rifles. The bolt carriers & heads used to be quality HK imported licensed parts which never had problems. Now they are made in the USA, & break, as they are not hardened properly. So in my experience, unless S&W issues a recall for me to send in my gun because of safety problems, I'm not changing anything, as that "production upgrade" could have been a "cost saving" production change. My 4 year old M&P40c has the black firing pin, & I'm not changing it as it works fine. After 30+ years in the auto parts, & gun business, I've learned "newer isn't always better". GARY

I don't think .40 accuracy was ever in question, I think the barrel update is only relevant to the 9mm.

Which one has better reset, the old one with apex ram or the new one with out?

One thing I have definitely noticed in terms of production changes, the roll marks nowadays are nowwhere near as distinct or deep as they once were. My "stainless" marked .45 FS from 2008 has way more impressive roll marks than my 2013 .45c.

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"Only hits count." - Air Power

I'm an idiot. Please ignore my previous post about not having any dimples ... I was looking in the wrong place. What I did find is my M&P FS has one dimple, and it's in the middle of my test fire dates (mid May). My 9c has two, and it is the "oldest" from April. The Pro has two (early May), and the CORE has one (late May). The Pro and CORE have a nice smooth trigger bar, but no flare.

Does this apply to the shields also?

A couple weeks back I purchased a new 9c and was surprised to see a test fire date of March-5-13. This one must have sat in the case for a while.

The barrel has 2 small dimples which some say is an update to the one dimple barrel. The slide stop looks to have the current flare/protrusion, it does have the audible and tactile reset which is not as audible as my shield, however it is audible, I have no idea about the sear. I have yet to shoot this one but I will say I like the trigger on the 9c better than the one on my Shield.

I just checked the sears on my Shield and 9c. The Shield which was test fired 5-13 has the mim sear which is more rounded, the 9c has the new production sear which was test fired 3-13. Maybe this explains why I like the 9c trigger better than the Shield.

The new M&P upgrades are phenominal. Much much much better!!! I have always felt the m&p was better than the __ock but these upgrades absolutely change the whole trigger aspect of the gun....Great job S&W!!!

Looks like the slide stops are the exact same part, only they bent the inner edge on one side for the audible/tactile reset. Wonder why all of them aren't getting the same treatment at this point including the 45 models which they seem to have forgotten when it comes to upgrades......at least for now I hope.

Maybe they will address erratic ejection from the 9mm?

Does anyone know which bullet weight is favored by the original barrel with the 1:18.75" twist?

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Audemus jura nostra defendere

I think the lighter bullets. If I remember what I saw Jerry say on one of his M&P videos, the 1:10 helps both the lighter and heavier bullets.

The .45 trigger bar is different, and last I was told, they expected testing to be done for the .45 models and the M&P 45 to start receiving the complete "upgrade" by the end of the year.

While there's been some slide stop lever spring revisions since the M&P's introduction for different calibers (original springs were unpainted, and then they were red, blue and yellow), the latest revision of the slide stop assembly ... with the yellow (heaviest) spring and the angled rear/lower corner of the inside of the right side of the ambi lever assembly ... is going to become the standard configuration for the M&P's.

It'll be easier than keeping 2 or 3 different assemblies for repair parts, depending on the caliber of the guns. I've still got some of the blue spring units and some of the earliest of the yellow spring units (developed for the .357's and then used in some of the 40c's, made before they added the inside angled corner).

I imagine I'll add some of the newer units to be put back against any repair usage ... once they can get enough of them for more than just trying to catch up with heavy new pistol production demand.

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Ret LE Firearms inst & armorer

Gentlemen,
I have a FS9 with a test fire date of 6/2011 and have installed a DCAEK and RAM.
It appears, from this thread, that both the trigger bar and slide stop have been redesigned since I purchased my M&P. Given that I have the DCAEK & RAM installed, will I see any benefit to upgrading to these newer parts?
The RAM provided reset where none existed before but I sure wouldn't mind something a bit more tactile.

As for the barrel, I have the older non-dimpled one with the slower twist. I understand that Midway is selling the newer 1:10 barrel. Does anyone know if their trigger bar and slide stop are the newer models?

Thanks for the help.

I'd not rush out and try to find the latest revision of the parts just for the supposed advantage of a "tactile reset".

Yes, the nice thing about the latest slide stop assembly revision is that it can help provide for some added inward pressure on the TB, to help the TB tail more briskly reset under the sear nose, and without having to add more parts, but I'd not think it's going to mean there's a dramatic difference in each and every gun.

I was inspecting a brand new production 9c for one of the guys, and even though his 9c has all the latest parts revisions my 2010 production 40c has a distinctly more noticeable "tactile reset" (and it's a stock gun). I don't notice it when shooting - as I shoot to trigger recovery, not reset - but he certainly did when I let him try it. He was very disappointed that his latest M&P didn't have a very noticeable "tactile reset".

Of course, once he was using his new 9c for a fast-paced qual course-of-fire he managed to short stroke the trigger because he was trying to hold it back to the "reset point", instead of letting it properly recover. At least he didn't experience the other type of problem that keeping a finger on the trigger under stress can cause, searching to find the reset point under stress, which is an unintentional subsequent shot. (These are often caused by the trigger being rocked under recoil, or by an unintentional muscle tremor or flinch, while the trigger is staged at the reset point. Not good at all.)

I worked with him on some more demanding drills and got him working on shooting to trigger recovery, getting his finger off the trigger so it could fully recover between intentional shots. His times quickly went down (although he wasn't aware of it, at first) ... his scores went up as his accuracy improved ... and halfway through the drills exercise he realized he wasn't feeling the travel distance, weight or "smoothness" of the trigger press. He was just functioning the trigger as needed, and was concentrating on making solid hits under stress.

Of course, some of the drills involved shooting while moving, shooting from new, different positions and postures and not being able to "index" his shooting arm during 1-handed close quarters reactions, so he had his hands full and wasn't as easily distracted by trying to distinguish the subtle nuances of "trigger reset".

Then again, he's a working reserve and has a CCW, so his primary focus isn't leisurely target shooting, but dedicated defense shooting.

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Ret LE Firearms inst & armorer

I have a very new and as of yet unfired M&P 40 FS, produced July 2013. The machined sear has a 'reset modification' profile pictured above that is much like the APEX sear. It also has the modified slide stop. Over travel and reset are fantastic in dry fire testing. Less than half the over travel and reset compared to my three month old Shield 40. Both triggers have gritty triggers due to the firing pin block. Both guns will get APEX firing pin blocks ASAP, and have any internal burrs removed while they are apart. The Shield will need a full up APEX carry kit to get it up to the level of the new full size M&P trigger. It's that good.

I also picked up a FS 9mm barrel from Midway. 2 dimple marks. fast twist barrel. Not quite 1/2 revolution in 4.25 inches. Looks like a 1 in 10 twist.

I just e-mailed S&W to ask if there have been any upgrade in parts on recently built M&P's since my 4 year old gun was made. They replied there were none.

Reference number: LTK111770304716X Please use this ticket number in any correspondence with us.
Subject: Question on my M&P 40c

Dear Customer,

There has been no change in your firearm at this time.

If further assistance is required please reply accordingly.

Sincerely,

Don

This message, including all attachments: (i) May contain technical data as defined in the International Traffic In Arms Regulations (ITAR) 22 CFR 120.10. Export of this material is restricted by the Arms Export Control Act (22 U.S.C. 2751 et seq.) and may not be exported or transferred to non-U.S. persons without prior written approval from the U.S. Department of State; and (ii) Is intended only for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and/or exempt from disclosure under applicable law. If you have received this communication in error, please delete it and notify the sender immediately. Thank you.

---------------Original Message---------------
From: GARY TANINBAUM < [email protected] >

Subject:
Question on my M&P 40c



Hello. I recently picked up a M&P 40c, ser # MFP0@@@. It shoots fine, but I am wondering if there are any upgrades or improvements in newly produced versions of this gun since the gun is 4 years old. It has only 200 rounds through it. I am not looking for free warranty work, but I am just wondering if newer guns got different [improved] parts. Sincerely, GARY TANINBAUM

It may be important to note that the articles in the OP were not written by S&W. Please correct me if I'm wrong on that point.

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Freedom isn't free.

N4KVE, I guess I'm not too surprised at their reply.

Do you have any dimples on the barrel? How many, mine has two (mfg early 2013). My slide stop is also the updated version, as well as the Sear. You should be able to see these when cleaning (without a complete tear down). Look for the dimple on the sear.

You can get all of these at Midway or Brownell's relatively inexpensive other than the barrel being a little more expensive. I imagine the trigger parts would be more beneficial for the dollar than the barrel. The question would be speaking with someone there to see if they are the newer versions, I'm not sure if the part numbers changed at all.

Sear Housing Block Assembly, Standard : SEAR HOUSING BLOCK ASSEMBLY, STANDARD | Brownells

Slide Stop Assembly : SLIDE STOP ASSEMBLY | Brownells

MP (Semi-Auto) | World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools - BROWNELLS

JFR

You are correct!

I think since S&W is on vacation, that response probably came from the night watchman who was bored.

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Minimize the variables

The reply came from "Don" @ S&W. Does anyone know who "Don" is? GARY

In a week or two I'm going to call S&W for the new slide stop. The picture in the Brownells link is the old slide stop. I'm not convinced they'll ship the new version.

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Freedom isn't free.

I plan to call and ask about the guiderod spring. I think that I have early ejection issues per may brass markings and some damage from primers. I hear that they are now using the green 16lb spring as in the .45. I may just buy one and see how it works. Does anyone know of any issues or reasons not to try this?

My .40 came with a green spring. Test fire date of 5/31/13. It is not the same spring as the .45. I also have a .45 and the springs are different lengths.

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Freedom isn't free.

That's right, now I remember that you started this once before. Does the .45 have a 4.5" barrel?

Yes

I'm not allowed to answer that simply because it has too few characters. So, to satisfy the computer overlord I have typed these two sentences.

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Freedom isn't free.

Smith does listen, it seems. My July 2013 build M&P40 has another new slide stop design. Instead of the old stamped trigger bar pressure area, it now has a stepped pad welded to the slide stop. The purpose appears to be to apply lateral pressure to the trigger bar to enhance tactile reset feel. Pictures attached.

I also purchased a trigger/trigger bar assembly from Midway to work on in an attempt to improve gritty trigger pull. The trigger bar on my gun is stamped "R". Pictured on the top. The one from Midway is stamped "S". It has a shallower engagement angle and it .015 inches shorter at the top of the loop. End result: it moves the sear engagement later in the trigger pull, and softens trigger pull. Combined with the new factory machined sear with a profile that mimics an Apex or a Burwell sear, overtravel is reduced and reset feel is increased.

My M&P and my Shield both had gritty trigger pulls. Simply polishing the machining marks of of the trigger bar contact point with the striker firing pin block removed all the gritty feel.

The stock M&P trigger bar loop, when viewed from above, did not fully engage the sear like the one on my Shield did. Simply tweaking the sear engagement loop slightly to the left so it would completely engage the sear had the pleasant effect of greatly improving reset "feel".

Bottom line: There is no longer as much need for aftermarket sears on the newest M&P. Stock parts are improving.

All the Shield needs is a trigger stop to limit overtravel. Take up is short and release is crisp. Overtravel is excessive, though.

Attached Images

	photo-2.JPG (73.1 KB, 598 views)
	triggerbar.JPG (73.9 KB, 662 views)

This is not correct in my experience. Admittedly, I have only sent in a couple of M&Ps since they have been introduced, but in both cases, they replaced not only affected parts, but other internals that had been upgraded since production began on the M&P.

Don't agree at all shields are not coming with the new sears and parts. They seem to be using the same mim S&W sear.
So the shield benefits a lot from a apex sear.

Even with the old sear, the Shield has a perfectly good trigger out of the box stop, so it's not really "needed."

However on my M&P40 & 40c I would like to replace with the new stock parts.

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unrepentant M&P fanboy

I didn't say it needs it. I said it benefits from it. Anyone who has changed the sear in their shield will back up this statement.

Has anyone seen the new ver 3 slide stop with welded pad yet?

Guys, if I might. The "welded" pad slide stop is the standard part now. The "bent" style slide stop did not see wide spread distribution. Probably due to wear factors, if I would guess. And these production design changes started with the Shield. S&W learned a way to improve the trigger pull and reset knowing that it was what the Public wanted. They incorporated that knowledge into the 9 & 40 line pretty soon after the Shield was such a hit.
Oh, and anyone having "weird" extraction problems(i.e., straight up or spotty extraction), replace the extractor. S&W upgraded that as well. Spring is same, unless yours has sacked.
Thanx. Happy New Year, All.
Ofc.JL

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LEO, Instr, Armorer, Gov's 20

My MP 45 FS has a born date of 4-10. The trigger has gotten much better with use.

The guns is stock and shoots great! Perfectly regulated for 230 grain ammo....shoots Ball and 230 HST same point of aim, where ever the white dot is!

Leaving it stock.... aint broke ... not fixing it!

Best

Bob