New M&P 9c and dead trigger

[RussB]

I got my gun back exactly one week after I shipped it. Thus, the gun was at the S&W shop for less than 2 days. According to the doc I received, it was repaired by "REPL SEAR HOUSING BLK ASY"

I would bet S&W installed a new sear block. TXPO

BRILLIANT

sorry, couldn't resist

 

[RussB]

I think the gun was fixed. Just shot about 130 PMC 115g bullets with no trigger issues.

There were no feeding or any failure to extract either but I did have about 3 misfired which I attribute to the cheap ammo I was using. The primer showed a good dent but it took a 2nd hit to ignite the powder. Am I right in blaming the ammo? I will try a different brand next time but I.hate to blow lots of mula for range practice.

I'm surprised to hear you had misfires with PMC ammo

 

[SMMAssociates]

Rebiker1:

Sounds great!

BUT, as long as you have some time, yank the striker assembly and clean EVERYTHING.... Sounds a little like something is retarding the thing. This should be unrelated to the sear, and could still be the ammunition, but who knows? Check the drop safety plunger, too, and make sure it moves freely with finger pressure. If it's not working properly (the trigger bar's "loop" moves it), the striker won't move. Since you're getting some impression on the primer, my vote is dirt someplace....

I had the dubious distinction of working on a Llama .40 a while back. It wouldn't fire anything but a club member's handloads. Turned out that he was using very soft primers.... Pulled the slide apart for cleaning (1911 copy, but not a clone) and found nothing, BUT, the Swartz safety bar apparently was "out of time", and had been beaten up by the firing pin, to the point that a large burr on the safety bar was retarding the firing pin, even if everything else worked.

The Swartz drop safety uses a pin from the grip safety to move an "L"-shaped bar that blocks the firing pin. If it's not raised up out of the way, the firing pin has a ring that can hit it. You have to remove the rear sight to get to it. It's clear that Llama expected something, because the rear sight has a witness mark on it!

Regards,

 

[Rebiker1]

I removed the striker and cleaned it. It was pretty clean though there was some oil in the "channel". Now it is totally clean and "dry". I'll have to test it to see.

Oh.. the drop safety plunger appears to be OK.

Thanks

 

[Willie300s]

TXPO:

No idea.... S&W "officially" started using the new blocks for non-MA sales last October, if you can believe what you see on the Web. However, it appears that they also just used what was handy, so what you got was a toss-up. The pipeline may also be long enough that some of the older blocks are still around in new guns. Allegedly, they're selling as fast as S&W can make 'em, but....

IMHO, if the OP has the new sear block, there's something else entirely involved, or the gun's got some crud or other problems in the sear assembly that's retarding the sear from grabbing the striker.

A broken or improperly installed trigger spring, or a bad trigger bar, can also muck up the reset. One reason for the RAM kit is the extra help the thing gives the far end of the bar. Essentially, it grabs the end of the bar and pulls it where it's supposed to be. The gun design shouldn't require this, and if the spring is right, it shouldn't be necessary, but it's a help.
Regards,

Actually, as far as I can tell, the RAM is more likely to cause the dead trigger problem rather than help it. The RAM pulls the trigger bar toward the sear which likely is causing drag against the sear during the cycle preventing the sear from popping back up. The stiffer sear spring will no doubt help but I don't believe this is the basic problem. My 9Pro had 2 dead triggers last Sunday for the first time after I installed the RAM on Friday. I am now RAMless..

 

[SMMAssociates]

Willie:

I hope Scott or Randy will chime in, because I can't quite get my head around it right now.

(Can't recall whether my 40C developed a dead trigger before or after installing the RAM - I did that later, after the DCAEK went in. Swapping the plunger & spring - Randy did it - fixed it.)

Unfortunately, Lisa didn't forget to bill me .... (In fairness to the gang at Apex, tossing a few bucks at them was a given. When they threatened to hold my daughter hostage, I thanked them....)

Regards,

 

[Willie300s]

I have nothing but great things to say about Apex. They have great products and the RAM is no exception. Many people feel their shooting has improved with the RAM. I do however believe that the RAM contributes to the dead trigger problem if you have the smaller sear spring. Probably the best combination is the RAM with the larger sear spring.

One question for everyone; Has anyone with a large sear spring had a problem with dead trigger?

I also believe the shape of the trigger bar is a factor. Mine fully engages the sear but I have seen several trigger bars that only partially engage the sear. This latter arrangement provides greater clearance between the sear and trigger bar during the rechargre cycle and I feel sure reduces the chance of a dead trigger.

Randy, if your listening, what do you think about all of this?
I just purchased a completion spring set for my pro9. Would the small sear spring included be stronger than the factory spring? If so, I will probably install it and put back the RAM and see what happens.

 

[spirit4earth]

Hey guys, please help a relative newbie understand what a "dead trigger" is. Thanks!

 

[Willie300s]

Hey guys, please help a relative newbie understand what a "dead trigger" is. Thanks!

It's when the pistol cycles normally but the striker does not reset. So you have a fresh round in the chamber but the pistol is not cocked.

 

[SMMAssociates]

I have nothing but great things to say about Apex. They have great products and the RAM is no exception. Many people feel their shooting has improved with the RAM.

Willie:

Shh.... Be nice to these guys and they'll keep coming back .

(But +1!)

I do however believe that the RAM contributes to the dead trigger problem if you have the smaller sear spring. Probably the best combination is the RAM with the larger sear spring.

Nobody seems to know why, but it appears that the popularity of the DCAEK kit and the concurrent appearances of dead triggers with and without the kits, seem to have resulted in S&W starting to slipstream the newer sear block, plunger, and spring into production. I know I'm not the first to ask Randy about it, but I was one of the first....

The larger sear spring does seem to help - the idea is to shove that sear up and keep it there so it's in place to grab the striker. If it's fluttering around, it won't.

One question for everyone; Has anyone with a large sear spring had a problem with dead trigger?

Haven't heard about it, but if you look at the design, particularly with dirty ammunition, anything is possible. IMHO, the upgraded spring & plunger (either S&W or Apex) has to help, but there's a compromise between the sear spring and the trigger pull. Just between us chickens, I think S&W used the original design because it helped deal with the drop safety plunger's drag effect. Apex definitely fixed that....

I also believe the shape of the trigger bar is a factor. Mine fully engages the sear but I have seen several trigger bars that only partially engage the sear. This latter arrangement provides greater clearance between the sear and trigger bar during the rechargre cycle and I feel sure reduces the chance of a dead trigger.

That's been something of interest, at least, for a while, too. The trigger bar is, IMHO, a bit of a kludge. It works, but is subject to all kinds of QC issues at the factory, and potentially easy to mess up at our end. You may want to bend something a little and see how it behaves.

There's a little nubbin on the sear or the block (can't remember where) that Randy suggested me filing back a bit, before doing the spring mod. Didn't work, but it did point out that these things are all but stamped out, and were designed to work reliably if kept clean. I really think S&W realized that "kept clean" may be a problem in LE guns. Not that guys won't clean the bore and lube things if properly beaten on by their armorers, if any, but the sear's a "detail strip" sort of thing that I wouldn't expect the average LEO (or M&P owner) to do. Who takes the sideplates off revolvers? (Who does it without damaging something?)

Randy, if your listening, what do you think about all of this?
I just purchased a completion spring set for my pro9. Would the small sear spring included be stronger than the factory spring? If so, I will probably install it and put back the RAM and see what happens.

Guess I can talk for Randy.... Both the upgraded S&W spring and the Apex kit springs are stronger than the original factory spring.

Just IMHO, be sure you put the RAM kit in properly, too. It's way too simple , but I'd believe anything. I've had more than one person tell me I couldn't put the drop safety levers back in a Colt Series 80 clone improperly. Wanna bet? I know I had to think about the RAM a bit. (I'm just above Bubba class. I can usually get the 1911 grips back on the correct sides. Usually....)

Anyway, don't be afraid to bend the trigger bar a bit if it feels like a good idea. I don't think S&W is scouring the streets press-ganging assemblers, but profit margins are profit margins and....

The RAM kit is supposed to force the trigger bar into proper engagement with the sear whether or not the trigger spring fails. (It does require you to manually re-cock the thing in that case.) Otherwise, the gun turns into an expensive club. Kinda Rube Goldberg to start - that spring is a long way from the sear - but I don't think it's too far off the wall. I can't see a properly adjusted trigger bar and a properly installed RAM causing any problems, but it's quite correct to presume that it could. Too many options ....

Regards,

 

[Willie300s]

Stu

I have seen the term "flutter" mentioned several times. For the life of me I can't imagine how the sear could flutter unless the sear spring was broken or totally removed. I replaces my sear spring last night with the Apex replacement and the original spring was in excellent condition. I can only conclude that it was not flutter that caused my two dead triggers last Sunday after I installed the RAM.

I believe my problem is the fit of the trigger bar which rides very close to the side of the sear during reset. I believe the RAM reduces this clearance even more during a cycle and creates enough drag to create an occasional dead trigger. Perhaps if I bend the trigger bar loop a little further away from the sear my problem will go away. Or I could just keep the RAM out. My trigger reset is fairly distinct so I probably don't need the RAM anyway.

 

[spirit4earth]

It's when the pistol cycles normally but the striker does not reset. So you have a fresh round in the chamber but the pistol is not cocked.

Would you then just rack the slide to get it operational?

 

[SMMAssociates]

spirit:

Yes.... But if the trigger spring breaks, you have a single-shot pistol, if you have the RAM. Otherwise, it's a club....

Willie:

The original spring is kind of light.... When the gun discharges, the sear is going to bounce around a bit - the trigger bar doesn't do anything, and the spring just isn't enough to hold the end of the sear "up" to grab the striker under certain conditions.

I'm not sure why the DCAEK kit makes this worse, but I can see where dirt and lubrication issues could. The sear is sort of free floating, other than the plunger and spring, and depends on those parts to hold it up if the trigger bar isn't forcing it down.

I suppose that you could bend the trigger bar a little to stop the problem with the RAM kit. I'm still not sure why it'd be a problem in the first place.

I'm hoping that somebody from Apex will chime in on this one....

Regards,

 

[Willie300s]

Would you then just rack the slide to get it operational?

You don't have to totally rack the slide. Just pull back enough to reset the striker.

 

[Willie300s]

spirit:

Yes.... But if the trigger spring breaks, you have a single-shot pistol, if you have the RAM. Otherwise, it's a club....

Willie:

The original spring is kind of light.... When the gun discharges, the sear is going to bounce around a bit - the trigger bar doesn't do anything, and the spring just isn't enough to hold the end of the sear "up" to grab the striker under certain conditions.

I'm not sure why the DCAEK kit makes this worse, but I can see where dirt and lubrication issues could. The sear is sort of free floating, other than the plunger and spring, and depends on those parts to hold it up if the trigger bar isn't forcing it down.

I suppose that you could bend the trigger bar a little to stop the problem with the RAM kit. I'm still not sure why it'd be a problem in the first place.

I'm hoping that somebody from Apex will chime in on this one....

Regards,

Stu

I'm sorry but I can't see the fluttering. Even the small sear spring is quite adequate to overcome any inertial force placed on the sear during firing. My Pro9 has about 2500 rounds through it and never failed to reset until I added the RAM.

I too wish Randy or someone else from Apex would comment on this.

 

[chuck s]

Because of the simplicity of the M&P design the same, small trigger return spring pulls the trigger forward and at the same time pulls the trigger bar (which also functions as the disconnector) to the left to allow it to slip under the sear.

Simple and effective. But just one spring doing both functions means a spring failure will totally disable the pistol. Pretty slim chance in a stock pistol, but it could happen.

Lightening the trigger weight by modifying this spring makes both trigger and sear reset less reliable.

-- Chuck

 

[Willie300s]

Stu

I'm sorry but I can't see the fluttering. Even the small sear spring is quite adequate to overcome any inertial force placed on the sear during firing. My Pro9 has about 2500 rounds through it and never failed to reset until I added the RAM.

I too wish Randy or someone else from Apex would comment on this.

Well I finally sent Randy a direct email yesterday morning regarding the problems I have been having with my M&P Pro9. I noted that at least with my pistol and the shape of my trigger bar, the RAM device is too long. The end of the RAM hits the side of the frame during a cycle preventing the trigger bar from resetting out from under the sear. I ground down the end of the RAM a bit and now it seems to function ok. Widening the slot a bit would have the same effect. I only mentioned this to Randy to get his opinion and perhaps provide additional insight into the dead trigger problem which is no doubt associated with the installation of the RAM device. I know they are busy and perhaps get several of these "helpfull" emails every day but so far, no response.

 

[SMMAssociates]

Willie:

No idea what's going on here.... Randy and Scott usually are very responsive, but they've got a lot of irons in the fire right now.

Wish I could be more help, but I'm thinking that the shape of the trigger bar end is wrong - the loops too broad, or something like that.

The RAM shouldn't hit the side of the frame.... Or at least I can't see how, but it's early today. I need to look at one of mine - maybe later tonight.

Regards,