I have been an M&P certified armorer for some time now, and work on a large number of PD M&P guns.  One of the things I began to notice on the guns that got shot the most was how much greasy crud they accumulated inside, particularly the frame.  I eventually realized that the basis for a lot of this crud was actually yellow and blue paint flecks.  These paint flecks were coming off of the internal parts of the firearm and staying in the slide and frame.  The combination of the heat creating inside the gun during firing, the oils and other residue were then congealing with these flecks and making a bunch of unwanted junk inside the pistol.

Obviously if you have ever had your M&P apart, you know that there are several internal parts of the pistol that S&W has painted from the factory.  If you just bought your M&P this is the perfect time to take your gun apart and orient yourself to these parts also.

What I have begun to do with every M&P that comes into our armory is remove the paint from every internal part I can.  I have also found that lacquer thinner works exponentially better than paint thinner for this.  You can scrub and scrub with paint thinner and not get all the paint off of some of these parts (particularly the recoil spring which has the thickest paint), but lacquer thinner strips it off immediately.

One the gun is apart, these are the three major parts I clean:

Recoil guide rod assembly (blue paint is coated on usually about half the spring on both sides)
Sear disconnect (painted yellow on all surfaces)
Slide stop spring (painted yellow on all sides)

Because it is tucked into the slide stop, you can't always get every little piece of yellow of the slide stop spring, but you can get most of it.  The sear disconnect is best done by removing the sear housing assembly and then removing the sear disconnect from this assembly.  This is not recommended by S&W to be done by a non-certified armorer however so fair warning.  You can screw up your sear assembly if you don't know what you are dong.  If you want to play it safe, you can still clean most of the yellow paint off of the disconnect while it is still secured inside the sear housing.

Remember that because you are stripping paint off of these items, you are also stripping their oils off.  I clean each part with another q-tip and then give all three a very very light touch of oil to protect them after the stripping.

The guide rod assembly is hard to get to with a q-tip (my tool of choice for this job), so I have soaked a rag with lacquer thinner and then run the rag edge along both sides of the recoil spring.  The RSA is particularly important to hit because I have seen high round-count guns where so much blue paint has come off of the RSA, and then immediately glued itself to the insides and facings of the slide lug where the RSA sits.  I'm assuming this happens during firing because the barrel and slide get hot and the paint vaporizes or melts, congeals on the slide and then cools again.

Obviously I have to point out that this is probably not recommended by S&W, and this is only my personal experience .  It would be an interesting question whether it voids a warranty or not, but I highly doubt it.  These parts will wear their paint off over time anyway.  The true reason (as best I can tell) for the paint is to indicate their purpose.  For guns with a magazine AND sear disconnect, I believe the yellow paint shows you which is which (since they look similar but not identical).  I suspect the blue paint on the RSA indicates a factory standard poundage, as there may be other weights with different colors attached.

Questions or helpful comments are welcome.

Sounds like kel-tecs required fluff and buff requirement for better/reliable opera.

Not a m+p fan, but good post op.

Txl

Thanks.  Unfortunately it's become almost required to drop an Apex kit into an M&P after you buy it.  No amount of fluffing and buffing can fix some of their trigger and sears.

I thought this was going to be a thread about fixing the trigger.

Guess we got lucky - My moms PF9 runs flawless even though she limp wrists the shit out of it. Didn't do anything but take it down and grease it.

IMHO the strip and clean is first.  It goes along nicely with the detail strip and clean you should do on a new gun from the factory anyway.  If you happen to have your Apex kit at the ready, then this is also the perfect time to drop it in while you have it all apart.

For those that don't have the funds for the Apex kit right away though, I would still maintain that this should be the first "mod" you do to the gun, especially since it costs next to nothing.

Wow

A good buddy of mine and myself did this simple trigger job to our M&Ps (his M&P40C and my FS M&P9 & M&P9c).

It's a complete night and day difference. I can't compare it to an APEX kit as I've never messed with one. Between us, we had all the stuff needed. If you have all the stuff and some general mechanical skills, I highly recommend you give it a try. It'll smooth out the trigger tremendously and give you a lighter pull.  

Yes the Burwell Trigger Job is Awesome and Free!! I have done it to a Older M&P Pro and a Newer 3/2014 M&P 4.25" 9mm I owned the Pro a few Years ago and it had the little to No Reset it needed the Apex Ram but I sold it before I got that far with it. The Newer M&P Fullsize I have now is Fantastic the Trigger feels around 4.5-5.0lbs and is very crisp and the Reset is Awesome it feels as good as My Sons G17 with a Taran Tactical Grandmaster Trigger kit!
I also removed the Yellow take down lever from the sear Block and Prefer to just pull the Trigger on a empty Chamber, rather than have a unessary lever in there that could possibly break and jam the Gun Up at a Bad Time. That lever does shed paint off of it! I say the Heck with Cleaning the Paint off of it take it out! After doing so You make sure the Gun is Empty with the Slide Locked Back Rotate the Take Down Lever and Lower the Slide while Holding onto it until it is even with the back of the Frame and while still holding the Slide Pull the Trigger to Release the Striker and the Slide will come off. I find this method easier than sticking something down in the Gun to flip the lever, and it is easier than taking the Slide off of a GLOCK while trying to hold the Takedown lever and Slide and pull the Trigger on the GLOCK.

I actually sent my C.O.R.E. off to Burwell.  It came back with a fantastic trigger.   Butter smooth take up, about 4 pounds of pull, and about a quarter inch reset with a click you can actually feel and hear.

The Burwell trigger job is really similar to the Apex drop in parts. The Apex advantage is that you don't wear through the case hardening and expose the softer steel to get the same results.

 

Can you buy the burwell and drop it in like the Apex or do they have to do it?

You can either send it to Dan Burwell, which is nice because he will smooth things over and do it perfectly to your specific gun. He can also adjust the pre-travel and over travel if you'd like that. http://burwellguns.com/Services.htm

I have both

I've done 5 trigger jobs doing the burwell method

when I compare my burwell, with the apex, they are about the same, with a slight edge to the burwell.

the take up with the apex is slightly less, because of the lighter spring,  but burwell break feels a bit better.

I bought the apex so I could compare, and see if I was missing anything.
It's a nice kit.

I do like the apex RAM

next time, I'll just do the burwell method again, and add the RAM

Tag-gage...

Interesting.  I never detail strip the frames of my pistols anymore.  Were you experiencing stoppages or failures because of the crud?

I have been considering the APEX trigger replacement.

How does the pivoting trigger feel?

Do you just get used to it quickly??

BIGGER_HAMMER