M&P 1.0 40S&W odd behavior

[ShrinkMD]

I was shooting my EDC and I started getting light strikes and the gun not firing. I field stripped it and out it back together, and the problem continued.

I then took out the striker to clean it and check the channel, a little dirty, but no obvious problems. Then I had difficulty reassembling the gun, the slide wouldn’t go on. It seemed like the takedown lever was loose or not moving correctly.

I finally got it back together, but then the gun wouldn’t fire. The trigger would make a clicking reset noise, but no bang. Cycling the slide had no effect.

I then came home and took the frame apart and cleaned everything. There wasn’t any egregious gunk built up, but I cleaned and managed to get it back together (without a slave pin either)

Now, the trigger isn’t making any odd clicking noises, the gun goes back together, and the trigger clicks once when I cycle the slide. Otherwise it’s silent. I noticed that the takedown lever doesn’t snap back into place as briskly as it used to when it was new, but otherwise the gun seems ok.

I haven’t fired it again yet.

All factory parts, only a few thousand through it, but carried daily so lots of dust bunnies at times.

Any thoughts on what happened and what I should do next? I’m surprised how my trusty carry gun just turned into an unreliable range toy until proven otherwise.

 

[M29since14]

I’m not qualified to diagnose that scenario, but if I depended on that gun for my safety, it would be on its way back to S&W.

 

[swsig]

I have a 1.0 M&P 40c that experienced similar failure to fire problems around 9,000 rounds. S&W immediately took it back and completely rebuilt it, replacing every moving part except the recoil spring assembly and the extractor. It performed better after that, but still had an occasional failure to fire. S&W then sent me a new recoil spring assembly, and that finished the job. Since then, I've shot over 4,000 rounds with zero malfunctions.

My advice: Do as M29since24 (above) suggests. Let S&W fix it for you.

 

[Saudade]

Sorry for the obvious questions, did you insert and empty mag to function check? Is the Sear release lever still "extended"? Does it have a magazine safety?

Take the slide back off. Pull the trigger. Does the sear drop? Pull and hold the trigger, sear should be "flush" with sear housing. The use a finger on your other hand to push the trigger bar tab (striker block) outward. Did the sear reset? Now release the trigger, Does the trigger reset?

 

[ShrinkMD]

Still at the mothership for repair, no word yet...

 

[ShrinkMD]

It returned today, the factory reported "Repair trigger" and "Passed Range testing." No other information on what happened or why...

How many trouble free rounds would you want through the gun and magazine before returning it to EDC?

 

[STORMINORMAN]

How many "trouble free rounds" did you initially fire prior to 1st putting it into your EDC...?

Cheers!

 

[swsig]

It returned today, the factory reported "Repair trigger" and "Passed Range testing." No other information on what happened or why...

How many trouble free rounds would you want through the gun and magazine before returning it to EDC?

My standard is a minimum of 200 trouble-free rounds. Most, if not all, of those should be the rounds that you intend to carry. My 1.0 M&P 40c had only two failures in its first 8,900 rounds. and as I said above, none in its last 4,000 rounds post-repair. So get to the range and fire away. If it can go 200 or more rounds without an issue, call it good and return it to carry duty. Good Luck!

 

[ShrinkMD]

And problems continue...several light strikes at the range. It's fresh ammo, they lit off the second time around, but click instead of bang is just unacceptable. I already entered another message at S&W, so it needs to go back again...

 

[LVSteve]

And problems continue...several light strikes at the range. It's fresh ammo, they lit off the second time around, but click instead of bang is just unacceptable. I already entered another message at S&W, so it needs to go back again...

Who makes your fresh ammo?

 

[ShrinkMD]

Who makes your fresh ammo?

That would come from the factory in my garage. CCI SP primers, roll sized brass, everything fed beautifully. Just the click instead of bang...

I was thinking that, but I've been reloading for many, many years, and never had issues like this. Some FTF in the past (hence the rollsizer which is amazing) but the only guns that go click sometimes are the 22 revolver with junk ammo.

 

[STORMINORMAN]

It dertainly is frustrating (as I know 1st hand) to receive a repair back and experience the same problem. Are you trying any factory ammo as well? Do the primers indicate a typical strike before the 2nd (successful) attempt?

There is an adjustment for the 1.0 trigger as detailed in the Apex videos: it shows how to measure and adjust the trigger bar loop, which can affect overtravel and reset.

Just a suggestion...

Cheers!

 

[swsig]

And problems continue...several light strikes at the range. It's fresh ammo, they lit off the second time around, but click instead of bang is just unacceptable. I already entered another message at S&W, so it needs to go back again...

Sorry to hear that. As STORMINORMAN suggests, the first thing I would try is some quality factory ammo. Be sure to test with your favorite self-defense ammo, not just range ammo. It's possible that even CCI could have made some hard primers. If the problem still persists with the factory ammo, ask S&W to send you a new striker and a new recoil spring assembly. (If S&W did not give you a list of the parts they replaced, shame on them. If they did not replace any parts, double shame on them.)

S&W listed everything they replaced when they repaired my 1.0 40c, but I still had some failures to fire. While they did replace the striker, they did not replace the RSA. Once I'd installed the new RSA they subsequently sent me, the failures to fire disappeared completely. Apparently my failures to fire were caused by the weak old RSA causing my slide to not always return fully to battery. Hopefully, the solution to your problem will be as simple as that.

 

[3rdgeargrndrr]

Certainly agree with the above.
Just making sure same ammo goes bang in another 40sw? No case head bulging & Plunk testing ok?. Also have you tried a heavier striker spring?

 

[ShrinkMD]

Fixed. Second time is a charm, they changed the trigger bar and now it works perfectly, same ammo. 200 rounds bang in a row. Back in the holster

 

[cracker57]

are you reloading your carry ammo? CCI primers are known to be hard primers, those who load their carry ammo and those who compete like federal primers as they are softer and it takes a lighter strike to make them go bang.

 

[ShrinkMD]

No, I've got Double Tap and Buffalo Bore for carry, the other stuff is for practice at the range...