M&P "dead trigger" issue

welder179

welder179

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Went and did some IPSC practice tonight with my M&P9 and on 4 (maybe 5) occasions i had a failure to fire as caused by a dead trigger from looking up the symptoms. However mine seemed to happen after a mag change with a round in the chamber still. This is after roughly 3500 rounds of flawless operation. Any of the fixes ive read about so far seem to suggest changing out sear block for apex kits but that would bump me out of production. What are the other suggested fixes?

Now before it gets said, yes the gun is clean. It gets field strip cleaned every time i use it, and get fully stripped down to every little piece aboit every 800rnds or so (just did it 200 ago) so the striker channel is clear and clean and the sear block spring channrl etc... and everything is very clean and properly lubed.
 
Try replacing the spring under the sear - and make sure you didn't lose any small parts, like the detent under the sear. Then check the trigger spring, make sure the pad inside the spring is intact - it's there to ensure that the spring lasts. Check the striker, striker spring and make sure the striker channel is bone dry. If you put any "reduced power" springs in the gun, put the factory ones back. Also make sure the ammo isn't weak enough to be causing the gun to short cycle. Are the mag springs still good? They're the single most overlooked component in any semi-auto.
 
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enefgee said:
Try replacing the spring under the sear - and make sure you didn't lose any small parts, like the detent under the sear. Then check the trigger spring, make sure the pad inside the spring is intact - it's there to ensure that the spring lasts. Check the striker, striker spring and make sure the striker channel is bone dry. If you put any "reduced power" springs in the gun, put the factory ones back. Also make sure the ammo isn't weak enough to be causing the gun to short cycle. Are the mag springs still good? They're the single most overlooked component in any semi-auto.
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Upon some further research it seems that may be the fix is the sear plunger spring, have to order one. As for ammo im using remington UMC bulk 115gr. But i just ordered some CCI blazer brass 124gr so maybe that changes everything. But i was suspecting after 3500 rounds now that some little inconsistencies were gonna start popping up, or some springs would start losing their strength.
 
welder179 said:
Upon some further research it seems that may be the fix is the sear plunger spring, have to order one. As for ammo im using remington UMC bulk 115gr. But i just ordered some CCI blazer brass 124gr so maybe that changes everything. But i was suspecting after 3500 rounds now that some little inconsistencies were gonna start popping up, or some springs would start losing their strength.
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I had 3000+ rounds through mine in a few months, no "inconsistencies" so far.

It sounds like you know what you're doing and what the problem might be but since you recently stripped it down completely I'd strip it down again and make sure nothing's awry.
 
Once you get the gun running again I would suggest you refrain from stripping the gun to the frame. Just clean the barrel and slides and re-lube the gun. It is not necessary to do the amount of cleaning you are doing. My bet is you have lost a small part when you were re-assembling the gun. The only issue I ever had with my original FS bought when the guns first came out was the striker broke after about 5K rounds., The original strikers were known to do this and S&W changed the design or supplier and solved the problem. The guns are extremely reliable. Sometimes to much love is not the answer.

Take Care

Bob
 
4n2t0 said:
I had 3000+ rounds through mine in a few months, no "inconsistencies" so far.

It sounds like you know what you're doing and what the problem might be but since you recently stripped it down completely I'd strip it down again and make sure nothing's awry.
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Yeah mine was pretty flawless up until last night. I can only think of three other jams or failure to feed instances. First jam was my fault and when i loaded the mag for the first time i pinched two rounds in and they got jammed. The other two were the ammo, round went off but wasnt full strength for some reason and the slide ending up short cycling. So havent had a problem with the gun and its ability to function untill now. So ill source out some replacement springs and give that a try. Ill update this thread if theres any further issues.
 
welder179 said:
Yeah mine was pretty flawless up until last night. I can only think of three other jams or failure to feed instances. First jam was my fault and when i loaded the mag for the first time i pinched two rounds in and they got jammed. The other two were the ammo, round went off but wasnt full strength for some reason and the slide ending up short cycling. So havent had a problem with the gun and its ability to function untill now. So ill source out some replacement springs and give that a try. Ill update this thread if theres any further issues.
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I guess what I'm saying is that it was working before and unless you can verify that there's something physically wrong with the spring itself (broken??? Unlikely...) it probably isn't the source of your issue.
 
Hitzy said:
None on these guns...
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Are you sure? I remember the magazine disconnect being an option when the M&P first hit the market many moons ago.

Regardless, it's very unlikely that the OP has one of those models.
 
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My money is on the op messing something up when he put the gun back together. I once bought a norc 1911 for $50 because the guy said it was broken he just had the sear spring installed wrong.
 
One of the guys at my range had the dead trigger on his M&P Pro not too long after he bought it new, but this was years ago. I thought S&W had fixed this as it was a known issue with some of the early guns. I think this is what got Apex off the ground making replacement trigger parts for M&P's.
 
tobin said:
One of the guys at my range had the dead trigger on his M&P Pro not too long after he bought it new, but this was years ago. I thought S&W had fixed this as it was a known issue with some of the early guns. I think this is what got Apex off the ground making replacement trigger parts for M&P's.
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The first "dead triggers" were due to broken strikers on the original guns. S&W changed suppliers ir re-engineered the striker and the newer version is virtually bullet proof.

Take Care

Bob
 
Canuck44 said:
Once you get the gun running again I would suggest you refrain from stripping the gun to the frame. Just clean the barrel and slides and re-lube the gun. It is not necessary to do the amount of cleaning you are doing. My bet is you have lost a small part when you were re-assembling the gun. The only issue I ever had with my original FS bought when the guns first came out was the striker broke after about 5K rounds., The original strikers were known to do this and S&W changed the design or supplier and solved the problem. The guns are extremely reliable. Sometimes to much love is not the answer.

Take Care

Bob
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+1 - I have 58K +/- on mine, and I don't shoot as much as I'd like these days, but I've never seriously cleaned it (detail strip and soak in an ultra sonic cleaner) more than once a year. Minor maintenance, springs, lube and a wipe down, and it's good to go. Regular tear downs are counter productive.
 
Wendell said:
x2

Apex Tactical has a video:

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Finally got around to taking the gun apart today and seeing whats up. The sear spring was still very strong with no precieved delay or flutter. So did some "dry firing" with the slide off and determined it was infact the trigger bar loop during the course of the guns use the bar had been bent down just enough that the gun would fire but only after the bar travelled all the way back then had to flex from the trigger being pulled down to the stop in the trigger guard. So adjusted that and now the sear engages a bit earlier, a bit of over travel now as compared to before but nothing to much, 1/16" approx. So there ya go boys make ttigger bar adjustments part of maintenace routine.
 
well I thought the problem was rectified, I was mistaken, still getting a dead trigger after performing a mag change with a round in the chamber. loading from an empty chamber has no problem, either from slide locked back or racking in a first round. it happens exclusively after a tactical reload, some local M&P medics have tried looking the gun over and nothing is jumping out at anyone for the source of the issue. ive contacted S&W now and informed them of the issue, waiting to hear back from them. but this is strange gentlemen, for the life of me I cant figure out what would be causing this, a dead trigger would have to be caused by one of three things in my mind:

slide not fully into battery, not sure why a mag change would cause a slide to get bumped out of battery.

trigger not reset, finger is out of trigger guard during mag change so extremely unlikely

or trigger bar getting pushed to the side off line of sear, again with trigger finger out of guard any side to side movement would just result in the trigger bar going back into alignment.

no parts are missing, damaged or worn, so I'm stumped... any other suggestions?
 
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