I’ve installed several of the Apex kits and the last 2 have had less than desireable results.
The last one was a Dec manufacture M&P FS 9mm, started off with a OK 7 lbs pull with a clean break. After the kit (no springs) the pull came down to 4.75 lbs but had a horrible stacking issue. The trigger would go through 3 stages before breaking and would break as close the over travel stop as possible. I ended up go back to stock and just polishing everything and am at about a 6 lbs pull, but no stacking and cleaner than with the APEX.
I had a similar issue with a Shield, quite a bit of stacking and a break in the low 4’s.
Luckily I got the kits from Brownell’s so I returned them, but on these particular guns the outcome was not desireable. Not sure if these new guns have a revision that is affecting the Apex kits or if it was just these 2 samples.
My best triggers have been Apex kits, one in a FS .45 and the other a FS 9mm. I have 2 custom triggers from Burwell and AI also.
I have done over 100 Apex triggers and I have never seen the problems you have spoken of.
You should have just called out to Apex and asked them for a bit of help.
Mike
I installed a AEK trigger,hard sear and spring kit on my 2013 production gun and have had no problems at all. Call up Apex they are very nice people.
My Apex duty/carry kits have worked out much better compared to factory. Though as I stated, I’ve used the kits. I didnt not leave the factory springs but switched to what the Apex kit came with.
So one each fullsize and compact and two shields so far. All in 9mm.
I’ve put in 6 or 7 DCAEK’s and, if anything, the APEX kits smooth out the trigger in every case.
I’ve used the product successfully several times and am very familiar with the operation of the kit and the firearm.
The issue I am having is slack out the trigger till sear/firing pin wall. The loop on the trigger bar should be articulating the sear and releasing the firing pin. What I am seeing is once you start pulling the trigger after the wall the trigger will move 2 to 3 stages before the sear releases the firing pin. It’s probably 1 to 2 mm, but very noticeable. My first inclination is to add a few thousands to the trigger bar loop to get sear engagement sooner. I was going back and forth with the Apex sear and stock and got the stock sear to an acceptable level so I just went back to stock.
The Apex trigger spring is there to make the trigger pull heavier on the duty kit. The sear spring makes little difference in my experience. The USB spring is going to affect the pull before sear engagement, I do use that spring since it does reduce the force necessary on the firing pin block.
I’ve sent 2 emails and PM’d Apex and did not get a response. Not trying to slag on Apex, I own a ton of their products and Randy has always been a great help and spokesman.
My message was an inquiry to see if anyone is having issues with new production M&P’s. My last 2, a Shield and a FS 9 showed the same problem. Both were Dec and after production.
Why don’t you pick up a phone?
Thanks for the suggestion, however I have exchanged emails with Scott and we are on our way to a solution.
Agree.
C4
Most likely, you need to do the following:
- Polish the trigger bar (where it engages to the striker block).
- Open the trigger bar loop so that it engages the sear sooner.
- Remove the striker block and make sure there are NO burrs in the slide (where the striker block rides up and down).
- Check to make sure that the trigger safety isn’t overly long and is hitting the frame (over flashing of the plastic piece).
C4
Trigger bar has been polished on striker block engagement surface.
I have not opened the trigger bar loop, however this is my #1 suspicion. I wanted to get a new set of feeler gages so I knew my starting point and exactly how much I was moving it. Also the trigger is breaking almost right against the over travel stop which Scott said could be a contributing factor causing some flex and the loop adjustment would help address.
As part of my process I always polish the striker block top, sides, and bottom. I also inspect the hole in the slide for burrs and once the block is installed I function test it for smooth operation. No problems there.
Have not looked as the trigger safety, but that is a good idea. I’m getting some flex in the trigger and what I felt was the trigger bar, before the striker is released.
Another issue Scott and I discussed and why I made this inquiry was if S&W had any new revisions that may be contributing to the issue. Scott threw out the possibility that the striker may have been lengthened causing more drag on the sear. I will put a caliper on this new gun’s striker and compare to my old M&P’s.
I’ve left the “call them” comments alone for the most part, but the bottom line is the hours just aren’t convenient for me 9-4:30 (-1 hour lunch). I’ve had good results in the past with email or PM’s. I know they are busy group.
I knew that the M4C.net group was a savvy M&P group so I threw it out there to see if any others had the issue.
Thanks to those who contributed.
I had a problem installing DCAEK and AEK, on an early 2012 model.
I installed AEK following apex’s video on youtube, however when i pressed down on rear of slide, the striker woudln’t release.
Ended up having to open trigger bar loop to ~.037"
I even bought a non-S stamped trigger bar from SpeedShooterSpec. but the dimensions/geometry were the same as my original S stamped one. and didn’t change anything.
however… it shoots fine. no problems. just a lot more overtravel than in Randy’s gun in his install video. and differ’s from others who always tout about how their M&P’s with apex kits now have zero overtravel. if you care about that sort of thing.
Recently installed a DCAEK in my 9c and had the same problem. Sometimes, the trigger wouldn’t break at all. This is the fourth Apex kit I’ve installed, but the first time this issue arose. After opening up the sear loop slightly, it functions perfectly.
Thought I would update this. I pulled the sear housing block from this new gun with a test fire date of 1/18/13. Big differences in the sear blocks. Some obvious differences, the ejector is held in place by the sear pin on the new block. There is no hole for the ILS on the new block so installing the Apex RAM is not possible. The rails that silde into the frame are different. Notice the shape of the lobes on the sear are totally different (these are factory sears). The old sear block will not fit in the new gun.
I did open the trigger bar loop .006 ( from the factory was .011) and it helped a bit, but did not make a drastic difference in the break or stacking issue.
The new M&P’s have a universal frame and sear block. Non safety models have the sear block as you show it with a cutout for the thumb safety spring and detent which make a RAM impossible to install. The frames also have safety cutouts and plugs. I purchased a couple RAM’s for my late 2012 M&P’s before I noticed this issue. I also tried to revert to the older sear block and new frame appears to have inadequate support for the ejector in the old sear blocks.
That’s funny, I just installed 2 kits in VTAC m&ps (9/.40). The hard sears have either a casting or machining mark RIGHT ON THE SEAR FACE! WTF?! HORRIBLE sear engagement. I ended up using a fine stone and surfacing the sear face myself, now it’s a very nice trigger pull. I even sent APEX a picture Ann’s a video of it. I was pretty disappointed to be honest…
Ive installed only around 10-15 APEX DCAEK kits in mine and others M&P’s.
The only issue Ive had so far is a single instance of an APEX small sear plunger spring not able to fit over the tail of the small sear plunger. A quick email conversation with APEX CS had a replacement to me in a couple of days.
All of the parts with this single exception have been trouble free.
Id contact them if there are any issues with their kits.
I’ve read nothing but good about APEX and everyone defends them. The fact remains the 2 sears I have are horrid feel. The kits are sold as “drop in” sears. It’s no biggie but damn, a ledge right in the sear face? Come on. I was nice and respectful but I highly doubt APEX will respond to my email…
Comeon, its much easier to suffer in silence and post on the Internet… 
What “help”? What for them to send new sears that may or may not have the same issue? It was an easy fix but should not have to been fixed…