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Failures with my new M&P45

3K views 9 replies 8 participants last post by  finalfusion 
#1 ·
So I took my new M&P45 to the range for the first time.



The Gun: M&P45 with NO manual safety and NO mag disconnect

The Ammo: Winchester White Box 230gr FMJ 100 rnd bulk pack.

Rounds fired: 80

Malfunctions: 3 (all in a row with same magazine).



Failure details: During firing magazine #3 (rounds 21-30) I had 3 failures where pulling the trigger appeared to move the slide back out of battery and the sear tripped, but did not release the striker. Slide returned to battery when sear tripped. Round in chamber did not fire (no striker hit) and slide had to be cycled to reset the trigger. After finishing out the magazine, I repeatedly racked the slide and pulled the trigger (probably 50 times). The problem happened again about 3-4 times during this series of dry firing. Problem never reappeared during the remaining 50 rounds fired.



Anyone with any clues as to the nature of these failures?



I need to put more rounds through it. I had to cut it short because it was after work and the range was closing. Other's have posted very good pics, so I didn't bother taking any.



Jason
 
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#2 ·
Jason,



If IIRC several members had a similar issue with either an M&P9 or M&P40. It sounds familiar and I tried searching but nothing turned up.



From what I remember it happened early on in life and never happened again. Keep us posted as you get some more rounds through. Also a quick call to S&W wouldn't hurt.
 
#3 ·
Yeah, as it was happening, I was like a bad movie character: "Wait...I know this..."



I've seen something written on failures like this before, but I can't remember where or even whether it was Glocks or M&P's or some other striker gun.



It was almost like the the trigger bar was pushing against something (the firing pin plunger maybe?) as it moved back and when the slide got back far enough (1/4" approx), the sear tripped because the striker wasn't where it was supposed to be anymore.



I also thought maybe the slide wasn't all the way in battery when I pulled the trigger, but I tried simulating that by holding the slide back a small amount and I never witnessed the trigger pull moving it back farther.



I'd like to take the slide apart, but I'm not sure I know how. Does it come apart just like a Glock slide?
 
#6 ·
Could this be due to trigger reset? I know with my 45 the trigger reset has very little tactile feedback to let you know the trigger is reset. During dry fire I can manipulate this reset just enough to somehow rest the trigger but not reset the striker. This results in a normal trigger pull but when the trigger breaks there is no twang of the striker releasing. I've never has this happen in live fire, but I don't see why it couldn't.
 
#7 ·
I had a couple of instances where the primer was struck but no ignition. And once where the trigger was pulled, sounded like striker released, but no ignition and no mark on the primer but a very slight mark on the very edge of the primer... VERY weird, never had anything like this happen to me with a gun before.
 
#8 ·
Your trigger bar could be out of line during it's travel. I notice I have to slide mine over when putting the slide back on or it won't slode on at all. That said make sure things are well lubed where the the sear assembly meets the trigger bar until the gun is broken in and the problem goes away. Good Luck!
 
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