M&P pro for idpa SSP

[tackdr1ver]

Hey all,

I have been shooting an M&P pro 9 in IDPA SSP. Recently, I have had a couple of incidents where it appeared that the weapon cycled into battery but when the trigger was pulled no bang. There was a round in the chamber. Have any of you encountered this, if so what was your solution? (I typically shoot factory WWB or blazer brass, if this helps)

Also, I am starting to look at going beyond the basic trigger polish that was done on it to tweaking a few things. Some of the things I am considering is the addition of the apex comp kit and changing the guide rod & spring weight.

What guide rod do you suggest to keep it SSP legal and what recoil spring weight do you suggest? Also, I have been looking hard at the sevigny comp sights. I would like a smaller rear notch and thinner front blade/smaller diamter fiber optic rod than factory. I would greatly appreciate any tips and advice on sizes, heights and configurations.

Thanks in advance,

Tack

[High Lord Gomer]

One of mine has done that from day 1. It fails to reset . I swapped slides and frames around on several of my M&Ps and the problem only occurs now about once every 250 rounds. I'm waiting for a lull in my schedule to send it back.

For me, racking the slide (sometimes as many as 4 or 5 times), usually resets it.

[grumpy.old.1]

I had an issue with mine not resetting with a new apex sear installed. After talking to apex they said that the frame to slide tolerances arent the best and he milled me a new sear with a different angle and all is well. Dont know how that will relate to the problems you guys are having but its something to look at.

[zhuk]

Does anyone know if this reset issue is confined to the Pro, or if it affects other MPs as well?

It's a factor since IPSC doesn't allow aftermarket parts/trigger-sear jobs etc, and I'm trying to decide between the 9L & Pro models.

[beastfrog]

Tack,

I am curious:

What ammo (weight,power)?

What sear?

Oil or grease for lube?

Anything else on the pistol that is not stock?

I've had it happen recently to a full size 9 with an Apex sear installed, slow fire, two different types of ammo. Have heard of it happening with PC sears (Pro's), Apex sears, custom sears, and even stock S&W sears. It's happened with 9s, 40s, 357s and 45s.

Edited September 23, 2010 by beastfrog

[tackdr1ver]

Tack,

I am curious:

What ammo (weight,power)?

What sear?

Oil or grease for lube?

Anything else on the pistol that is not stock?

I've had it happen recently to a full size 9 with an Apex sear installed, slow fire, two different types of ammo. Have heard of it happening with PC sears (Pro's), Apex sears, custom sears, and even stock S&W sears. It's happened with 9s, 40s, 357s and 45s.

beastfrog,

Typically I use factory Winchester White Box or Blazer brass both 115gr PF unknown. Sear is stock, however it has been polished lightly by a local gunsmith, no geometric modifications have been done. I typically use Hoppes 9 to clean and, Breakfree CLP and Militec 1 on different places for lube. Everything else is stock with the exception of skateboard tape on the grip which is nowhere near the slide so I can't see where it would be an issue.

Conversely, I have a M&P 40 full size for limited major which I installed the apex sear myself. And I can tell you that I have easily put over 2k rounds through the 40 after installing the apex sear. To this date I have not had any issues whatsoever as far as function goes. The only gripe I have is that the trigger breaks a little differently each time I get on the trigger. In retrospect, I should have had a gunsmith tune it but I can live with it for now. Trigger weight was significantly reduced by installing the sear alone, I feel the other parts would also gain marked improvements.

[beastfrog]

Thanks for the info!

Not good news on the stock sear. My pistol had about 2K rounds on the Apex sear before it started to dead trigger on me. I was going to put the stock sear back in and see what happens but am not sure that will eliminate the issue.

I'm starting to think there is a problem with the design. I've heard that S&W replaced the sear blocks on the NC State Police guns because of this problem. The replacement blocks were similiar if not identical to the Massachussetts sear blocks. These have a larger stronger sear spring and plunger. Wish they would replace all my sear blocks too.

Edited September 23, 2010 by beastfrog

[Flork]

The dead trigger issue seems to currently be the weakest point of the M&P.

IMHO it's a problem with the sear not sitting high enough up to catch the striker on the return of the slide. This is caused by a metallurgical issue that wasn't foreseen by the engineers that designed the gun. The Melonite surface on the slide is just too hard and the Sear Housings are the wrong material and aren't hard enough to stand up to the stress of the slide running across the surface with so much force.

As I understand it, the factory has been working on this issue, but I don't know their solution just yet. We've been drilling the Sear Housings and installing MA compliant Sear Plungers and a different spring to fix the issue, so far we've had good luck with that solution.

Scott

[want2race]

Easy fix if the sear engagement is too small (sear too low on striker). Remove sear, remove material under the FRONT of the sear. This allows it to raise up higher and engage the striker with more material. Go lightly, a little goes along way. This may not fix YOUR issue, but it's something to consider and look at.

FYI, an orange Glock inspection rear plate fits the M&P slide so you can visualize the sear engagment.

[Flork]

I've done exactly that on more than one Sear, it does help some, but you have to be careful about it ad make sure not to take too much off.

I'd suggest taking .005" off, that will give you .008" more engagement on the Sear. After the .005 I'd only go another .001 at a time if that.

[beastfrog]

The Melonite surface on the slide is just too hard and the Sear Housings are the wrong material and aren't hard enough to stand up to the stress of the slide running across the surface with so much force.

Scott,

Thanks for that input. Are you implying that the sear housing block is being worn by the slide and thus changing the amount of engagement between the sear and firing pin? or is the block flexing under stress allowing the engagement area to change?

Edited September 23, 2010 by beastfrog

[Flork]

The Sear housing block is wearing. Remove your slide and look at the rails....you'll see clear wear lines from material being removed.

Scott

[beastfrog]

The Sear housing block is wearing. Remove your slide and look at the rails....you'll see clear wear lines from material being removed.

Thanks. I'm at work now and don't have pistol with me so I'll be checking that tonight.

OK so I got home and checked the rails. I see bare metal where the black has worn off but no troughs or wear lines that would parallel the slide motion. I can't see this being a problem unless the sear/striker engagement is too small to begin with.

Edited September 23, 2010 by beastfrog

[Flork]

I'll snap some shots of my 9L tomorrow morning.

[High Lord Gomer]

The Sear housing block is wearing. Remove your slide and look at the rails....you'll see clear wear lines from material being removed.

Scott

It happened from day one on one of my Pros but has never happened withmany thousands and thousands of rounds through my other "regular" M&Ps.

is the sear block different on the Pro?

[Flork]

The Pro sear is shorter than the standard, so it's more likely to have the dead Sear issue because of the way the sear rocks on the pin.

We've found that the standard size Sear Spring is simply too small to have enough power to make the Sear stay in the up position to catch the striker. That's why the MA guns have better luck, the Sear plunger and spring have enough mass so the Sear doesn't over come them via inertia.

[kend]

We just finished a batch of sear plungers and put them on the website, we have the small and large if anybody wants to convert theirs to the large plunger. You'll also need the larger spring to go with it, we'll have those as soon as Apex finishes them.....

[tackdr1ver]

Kend,

Do you know if there is any difference in power of the apex sear spring and the factory? I was considering just swapping everything out for the apex competition kit. But it is a moot point if the original problem remains