Sear Flutter?

[Jack W]

S&W M&P 40C, early model with the small sear spring.

Anyone heard of sear flutter? I was told that could be what happens with a live round in the chamber and no 'click', like gun failed to cock.

 

[Sam7sf]

Never had it happen on any mp first gens I had.

 

[candcallen]

https://www.mp-pistol.com/threads/dead-trigger-bent-trigger-bar-or-sear-flutter.26165/

ETA just passing on the link. Do with it what you will but I suggest copious research.

 

[baboon]

Sounds like a mighty woke answer to me.

 

[Sasquatch]

Aftermarket trigger, or OEM? I've had a number of M&P's and never had issues, but I have also left the guts of them all bone-stock so far. The most I ever did on one was play with the sear loop to see if I could improve the trigger break by opening / closing it a little.

I've had dead triggers in other guns, but never an M&P.

 

[crosseyedshooter]

It was a known issue and you can get a newer sear block (3003148) and sear spring (399670000) from S&W for about $20. I’m not sure if you can reuse the old sear return plunger, but the new one is just a few dollars (392280000).

ETA: This affected early 1.0 pistols and pretty much everything since maybe 2012, don’t quote me, has the larger 1/8” sear spring.

 

[Sam7sf]

Did not know that. Guess I got lucky.

 

[Jack W]

Ended up getting a new sear block housing from Midway and then installing an APEX trigger kit. Now to load up some mags and try it out.



EDIT: Ran several mags through it, different loads / brands, and no malfunction + trigger reset is quick. Pull is lighter also.

 

[Glenn B]

https://www.mp-pistol.com/threads/dead-trigger-bent-trigger-bar-or-sear-flutter.26165/

ETA just passing on the link. Do with it what you will but I suggest copious research.

Much of the intended improvements and the apparent results of his intended improvements that the OP mentioned in that linked thread are why I do not screw around with the internals of my firearms by trying to make them better than original. I will repair things that are busted (like an ejector) or worn out (like springs) when I have good instructions on how to do the job but that is just about it for internal fiddling. I may go a bit further with a Glock but I was an Advanced Glock Armorer so am more comfortable working on them; still - I'd only use original Glock parts. The only other things I usually will do to a gun to improve it is to change the grips, add glass, or maybe add some other type of sight. Oh yeah, I also have refinished some stocks and made them look better than original but changed nothing about how they fit or function.