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M&P failing to reset trigger after chambering next rd


Heathen

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Hello again,

I tried all the possible permutations I could think of but couldn't find an existing topic on this.

During the last couple of range sessions with my M&P Pro I have encountered multiple failures to fire where after firing a round and chambering the next the gun fails to reset the firing pin and trigger.

I've ruled out light primer strikes and have completely released the trigger between shots allowing the trigger to return all the way.

I did a general search on the web and some people claim this is a manufacturers defect. The M&P is ~5000 rds old.

Does anyone have any idea of what might be going on or a good source for info?

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Mine happened about 400 rounds after a trigger job done by a previous owner. Very odd. It worked then it didn't. I was advised to put in a RAM. No joy. I then took to a smith who replaced the trigger and trigger bar. He said the other one was bent. I suspect it was intentionally bent in an effort to give it a shorter reset and once it wore in a bit it began the dead trigger problem. However it could have been inadvertently bent during a cleaning I suppose. I have shot 5K through it since the new trigger and bar and it has worked fine.

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What's the "born on" date of your M&P, as can be found on the fired case envelope (and frequently, the side of the blue Smith box it came in)?

The dead trigger issue was common with the old-style sear spring; it has since been corrected.

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Heathen, if you look on the label on the end of your box to the right of your searial number below the product number you will find a number like 9068 this number is the manufactur date,to break it down the first number or two is the year with the last three being the day of the year.So with 9068 it would be 2009 on the 68th day(March 8th 2009.)

Another one I have handy is 0361 or 2010 on the 361st day (December 27,2010.)

I hope this helps. Good Luck.

Edited by Damol
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Heathen, if you look on the label on the end of your box to the right of your searial number below the product number you will find a number like 9068 this number is the manufactur date,to break it down the first number or two is the year with the last three being the day of the year.So with 9068 it would be 2009 on the 68th day(March 8th 2009.)

Another one I have handy is 0361 or 2010 on the 361st day (December 27,2010.)

I hope this helps. Good Luck.

Oh, there it is - thanks. It was put together some time in July 2010. Does anyone happen to know when the update occurred?

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Heathen, if you look on the label on the end of your box to the right of your searial number below the product number you will find a number like 9068 this number is the manufactur date,to break it down the first number or two is the year with the last three being the day of the year.So with 9068 it would be 2009 on the 68th day(March 8th 2009.)

Another one I have handy is 0361 or 2010 on the 361st day (December 27,2010.)

I hope this helps. Good Luck.

Oh, there it is - thanks. It was put together some time in July 2010. Does anyone happen to know when the update occurred?

Not super sure when they started changing the sear springs, but on the box for my M&P40L the manufacture date says 1027 - so January 27, 2011, and mine still had the older, smaller size sear spring and plunger.

I can say that within 250 rounds of installing an Apex FSS trigger kit (and ignoring the instructions recommendation to use an updated sear housing block), I started getting a dead trigger - right in the middle of a match. Talked to Randy at Apex and after telling him the problem, his first question was, "Are you using the older style sear spring?" Ummm.... Yeah. He diagnosed it as sear flutter. I ordered a new style sear housing block (amazingly I was able to find one in stock), and haven't a problem many 1000s of round later. You can send your sear block to Apex and they'll drill out the sear spring hole and install the larger spring and plunger and ship it back.

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I called Smith & Wesson and they said any M&P made after I believe August 2011 they should have the issue cleared up. If you have any questions, have your serial number, model number, and call them at 800-331-0852. Expect to be on hold for 10 minutes, but they will give you all of the correct info you need.

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  • 2 weeks later...

My early 9Pro was doing that. It was extremely perplexing to get fixed. No amount of dryfire/slide manipulation could duplicate it. The slide moving rearward as little as a 1/4" will reset the sear. It only did it firing live ammo. And I always had a live round in the chamber when it occurred. I found that I needed to tweak the trigger bar a miniscule amount to fix it. About half way along it's length it was contacting the frame and "bending there" instead of moving off of the sear. It's been perfect ever since except when my daughter shoots it and this is a totally different issue. She can actually limp wrist it into a dead trigger when she gets tired and gets lazy with her grip. Her regular M&P 9 does the same thing. I still haven't figured it out, I can take both guns and do flawless mag dumps, but there is some weird juju going on with the sear in recoil with her if she doesn't concentrate on her grip. Some sort of harmonic/timing thing I suspect. I have been able to duplicate it by firing once or twice but would rather not say how, if you know what I mean. :o Bear in mind that she weighs about 110lbs soaking wet.

S&W has a different sear spring I think for the fix. If you have the later spring check the mp pistol forum mentioned before, there is a photo of the trigger bar issue I had going on. It fixed mine.

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  • 5 months later...

Bump to see if anyone has found a true solution to this:

My M&P Pro 40 started doing the "dead trigger" think in April. I have the current sear block/spring. Gave it to my gunsmith who tweaked the thing, put 40 rounds through it with no failure. He gave it back to me, and it died on the 3rd shot. Ordered a new trigger bar and installed. Got dead trigger in first magazine. Swapped slides with a friend who has a 4.25 M&P. I had my grip and his slide assembly (he, obviously, the reverse). My setup worked fine, and his experienced the dead trigger (albeit not as frequently).

I thought I had isolated the failure to my upper, so I ordered a new striker assembly. I put it in on Friday, bought some White Box and took it into the woods. 3rd shot, failure to reset.

I'm ready to melt the gun down for scrap. Can anyone tell me if they have fixed this?

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Bump to see if anyone has found a true solution to this:

My M&P Pro 40 started doing the "dead trigger" think in April. I have the current sear block/spring. Gave it to my gunsmith who tweaked the thing, put 40 rounds through it with no failure. He gave it back to me, and it died on the 3rd shot. Ordered a new trigger bar and installed. Got dead trigger in first magazine. Swapped slides with a friend who has a 4.25 M&P. I had my grip and his slide assembly (he, obviously, the reverse). My setup worked fine, and his experienced the dead trigger (albeit not as frequently).

I thought I had isolated the failure to my upper, so I ordered a new striker assembly. I put it in on Friday, bought some White Box and took it into the woods. 3rd shot, failure to reset.

I'm ready to melt the gun down for scrap. Can anyone tell me if they have fixed this?

Don't melt it, send it back to S&W and let them sort it out. Sounds like you have tried all the obvious issues, including the trigger bar (which some people bend to change trigger reset) and sear block. My only other thought is that if it is isolated to your upper (because your friend had a problem with your upper on his lower) is either the striker block or the striker itself is hanging on something.

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