Apex FSS Install Hiccup

[FilmMkr]

Hey there -

Using THIS Apex video as a guide, I've installed the Apex Forward Set Sear and Trigger kit on my M&P 9, and it seems I've hit a stumbling block.

In the installation video (at 16:23) there is a jump cut immediately after Randy installs the ejector. The vid cuts to him talking about "getting the surface of the RAM lined up" and he sort of fumbles around a bit before inserting the trigger bar. When he DOES install the bar, there is a positive lockup and an audible click. He then slides the sear block into the frame easy as pie.

On my setup, the trigger bar is not as positively engaged and the sear block is sort of loose on the bar. There is no notch on the sear pivot pin as there appears to be on the RAM Randy is using. Nonetheless, I line up the trigger bar in the open slot visible on the right side of the pistol, slide the sear block into place, install the safety and the roll pin and check operation.

The trigger bar moves, the sear is engaged and moves up and down via the trigger bar, everything looks hunky dory. The problem starts when I pin the trigger back (as shown at 18:07) and move the trigger bar over to disconnect it. When I release the trigger, the trigger bar does NOT snap back under the sear cam as it does in the video.

After putting the top end back on the gun, I try the trigger. It moves straight back. I can feel the tension on the spring, but the trigger does NOT click or release the striker.

Can anyone provide me with any clue as to what I might have done incorrectly?

Thanks.

 

[southchatham]

Did you put and empty magazine back into the gun to reset it. If not try this first.

Also try squeezing the trigger really hard after you think it wont go back any further and see if the extra pressure helps. I had this problem with their sear, I had to pull the trigger past where it should stop at the frame with one of my guns, the other worked fine.

 

[FilmMkr]

Did you put and empty magazine back into the gun to reset it. If not try this first.

Yes, I did. No joy.

 

[southchatham]

Yes, I did. No joy.

Try the extra trigger pressure, like I said I got a defective sear on one of my guns.

 

[FilmMkr]

Try the extra trigger pressure ...

Thanks for the reply, but I'm not sure what you mean by this. I've applied as much trigger finger pressure as possible. It pulls completely to the rear and won't go any further past the stop.

I'm thinking that the angled surface of the trigger bar might need to be reduced slightly and polished to slip back under the sear cam. That still does not seem like it would solve the issue of not releasing the striker, however.

 

[southchatham]

Thanks for the reply, but I'm not sure what you mean by this. I've applied as much trigger finger pressure as possible. It pulls completely to the rear and won't go any further past the stop.

I'm thinking that the angled surface of the trigger bar might need to be reduced slightly and polished to slip back under the sear cam. That still does not seem like it would solve the issue of not releasing the striker, however.

What you did is what I was suggesting. Mine did the same thing, but if I pulled just a hair further it would break, sometimes. So I figured the sear was angled wrong or something. I am positive mine was installed properly. I gave up and put my factory parts back in.

 

[FilmMkr]

Okay, I'm making some progress. I polished the contacting lobe on the trigger bar first. This helped a bit, but I could still see a tiny bit of binding where it contacted the side of the sear as it tried to return to its starting position under the sear.

I removed the sear block, then the sear proper, and polished the cam lobe on the sear. After reassembly the bar consistently returned to the starting position.

I reinstalled the slide and the striker would fire intermittently, say once every four or five attempts. I found that if I racked the slide and the striker did NOT fire, if I re-racked and then tapped the side of the slide, the striker WOULD fire.

So I'm getting closer . . . .

 

[FilmMkr]

I realize that this is not a very interesting thread, but apparently I'm the only person on the board who has encountered this issue. I'm going to update it for posterity so that if anyone has these same challenges in the future they can find the answers by searching the board and not fumble along using trial and error like I did.

I did manage to figure it out though, and in doing so I now understand exactly how this firearm operates and can now detail strip and reassemble my M+P with confidence.

As it turns out, I was on the right track. I spoke with John at Apex and he said that this is not an uncommon problem with the Forward Set Sear and Trigger kit. Since the M+Ps are basically mass-produced firearms, the tolerances vary pretty widely from pistol to pistol. Apex machines precision anodized parts, but ultimately the tolerances of your specific pistol will determine exactly how easy the install actually is.

(This variance in QC is probably why southchatham had difficulty with his sear, yet others have not.)

John recommended that I use a feeler gauge to determine a baseline measurement of the sear engagement loop (the "shepherd's loop) on the trigger bar. Then I'll use a pair of needle nose pliers (without the serrated jaws) to close the loop in .005 increments. This will help the loop slide under the sear and release after the slide is racked and allow the striker block to be released smoothly when the trigger is pressed.

I'll wrap this up after I finish the operation this evening.

 

[southchatham]

Thanks for the update.

At least I have an idea of why my apex sear worked great in my 9c, but not in my full size 9.

 

[Randy Lee]

Hi,

It sounds like there may not be enough trigger pre travel. In essence the pre travel limit tab on the front of the trigger is not allowing the trigger bar to return far enough forward to let the trigger loop move forward of the sear cam.

This seems to be more common in the older version trigger bars made before march of 2011. There could also be some plastic flashing on the front of the frame cutout for the trigger that is interfering. An easy fix is to use an emory board for fingernails or a small file to remove the offending plastic until you can do the function test and see the trigger loop move forward of the sear.

Hope this helps,

Randy

 

[FilmMkr]

Thanks for the reply, Randy - I really appreciate it! I will try that this evening.

 

[Randy Lee]

Please let me know if you run into any problems.

Randy

 

[stainless1911]

Watching this thread...

 

[FilmMkr]

SUCCESS!!

The problem was the sear engagement loop ("shepherd's loop") that makes contact with and moves the sear cam lobe. Using John's suggestion, I took a baseline measurement using a 22 blade feeler gauge. The opening was about eighteen thousandths. Using non-serrated angled needle-nosed pliers, I reduced he loop by four thousandths to start, reinstalled the sear block and safety, put the 1/8" roll pin back in lace and tried it. Fired three times, then quit.

Took the pin out, disassembled everything again, reduced the opening another five thousandths, reassembled, and viola! Now it drops every time, so I am stoked! The trigger breaks very much like my wife's Springer 9mm 1911. Not as crisp as my custom guns, but a LOT better than the fifteen-foot long pull of the original trigger.

So what did I learn from this?

Well, first of all, I learned how to tear this gun completely apart and put it back together again. I've done it enough now that I can detail strip it and feel uber-confident in my 'smithing abilities re: the M+P platform.

Inside of a week, I learned this pistol inside and out. I have a thorough understanding of the M+P platform and how this particular striker-fired pistol works. I now know how to troubleshoot this pistol and can tear it down and rebuild it on the range if necessary.

I was able to puzzle this problem out on my own, and with a simple phone call to Apex on Monday, learned an inside trick about how to fine-tune a technique using simple tools.

And last, but certainly not least, I learned that Randy and John and the guys at Apex are really great guys, are top-shelf precision parts manufacturers and - more importantly - are outstanding at customer service.

I am really looking forward to the RAM kit for safety models and will most certainly invest in more Apex parts kits and systems in the future!

I'm headed to our club in the morning to try it out on the plate rack and then some bullseye trials to see how much better it shoots.

 

[stainless1911]

Thanks, and congrats, I love customer feedback when I'm about to spend a lot of money. You have boosted my confidence as well in doing this project myself.

 

[stainless1911]

Dont forget to let us know how it went.

Hey Randy, can I put the spring from the competition spring kit, in place of the trigger spring on the FSS kit to achieve a ~3 pound pull? Also, which sear spring would I use, the competition one, or the one in the FSS kit?

 

[Rainman61]

I spend $30 having a S&W Certified Armorer install my Apex DCAEK kit. Apparently money well spent.

 

[Randy Lee]

Dont forget to let us know how it went.

Hey Randy, can I put the spring from the competition spring kit, in place of the trigger spring on the FSS kit to achieve a ~3 pound pull? Also, which sear spring would I use, the competition one, or the one in the FSS kit?

Hi,

You can use the factory trigger return spring and sear spring. They should give you about a 3 lb pull. The sear has a different weight distribution, so running our competition sear spring might lead to sear bounce. The competition trigger return spring might be too light and not add enough forward resistance to let your finger deactivate the trigger safety before the trigger starts to move. In this case it might lead to the safety ledge bumping into the frame and result in a snag in the trigger pull...

-Randy

 

[FilmMkr]

I spend $30 having a S&W Certified Armorer install my Apex DCAEK kit. Apparently money well spent.

Yees, but what did you learn about detail stripping, troubleshooting, and working on your pistol? Wouldn't that be worth thirty bucks?

 

[stainless1911]

Thanks Randy. I really can't wait to get this stuff in the gun. With your videos, I know that I can do it. I'm mechanical, but not much gunsmithing experience. I reload, so I know what difference a thousandth makes.

I'll be putting the RAM in at the same time. Does the RAM replace a part in the gun, or is it and additional piece?