M&P 9 dead trigger?

[SIKwitIT]

ive had my m&p9 for about 5 years now and up until recently its been 100% reliable. About 4 years ago i put in an apex carry/duty trigger kit and have put roughly 4k rounds through it with out any issues. Then recently I put in an Apex RAM and took out the mag safety and replaced it with the correct s&w spring instead of cutting down a ballpoint pen spring. Put about 200 rounds through it with no problems. Then just this last shooting trip i had 3 dead triggers in just 100 rounds. It cycles and ejects the round perfect but when i go to pull the trigger i get nothing. Any suggestions? Any springs that should be replaced at all over time?

[sffred]

Is your FTF a failure to feed or a maybe a failure to fire? (which should be called LPS/light primer strikes)

My suggestions is to disassemble and clean your mags inside (might be gum'd up) if your having feeding problems.

And if it is a LPS I suggest cleaning and lubricating your FP, and FPS, or it could just possibly ammo. sometimes primers are over crimped/pressed ever so slightly. Try another box of ammo (if it's the same manufacturer make sure lot# is different)

[SIKwitIT]

Sorry its failure to fire. And the trigger doesnt reset, so it will eject a round, chamber a round, but when i squeeze the trigger it does nothing, as if the gun is not cocked. I will then barely pull the slide back far enough to reset the trigger then when i pull the trigger it goes boom

[NiteQwill]

Check your trigger bar loop.

Your sear may also not be engaging your firing pin, usually because it is worn out or out of spec.

[crosseyedshooter]

If your sear housing block takes the Apex RAM, then it's the old version. I think around 2012, S&W updated the block with a larger spring. Apparently, fast reset sears like the Apex can result in a dead trigger because the small reset spring wasn't strong enough to reset fast enough.

Apex will upgrade your sear housing to the larger spring or you could look for a stronger spring of the same diameter.

[Tiberius]

IIRC, the early M&Ps had a known dead trigger issue. I'm not sure how that plays with the mods you've already done, but it might be worth tracking that down.

The link below talks about the sear and plunger being a bit too small, causing "sear flutter."

http://smith-wessonforum.com/smith-wesson-m-p-pistols/205989-dead-trigger.html

[SIKwitIT]

Okay thanks for the leads guys. Im going to start by taking the RAM out and see if that makes a difference then go from there

[9mmepiphany]

It is likely the small sear reset spring/plunger...maybe the trigger bar loop.

At 4k+ rounds, when was the last time you changed your springs

[teflondog]

Replace the sear spring with the stronger Apex spring. Over time that spring wears out, which causes "sear flutter" during recoil and the sear doesn't catch the striker. Your trigger bar loop should also be opened up to allow a small amount of trigger over travel when using Apex parts. Randy from Apex has a youtube video on how to adjust the trigger bar loop.

[SIKwitIT]

Thanks! Ill check that out. And i have never replaced any springs other than the ones supplied by apex with the carry/duty kit