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MCX and aftermarket triggers

33K views 27 replies 18 participants last post by  pig4bill 
#1 ·
Did a search and the last thread about MCX and after market triggers was in the DEC/JAN time frame and the recall was still being worked out.

It's May now and I am looking to buy an aftermarket trigger for my MCX with the G2 carrier group.

Talked to Sig Customer Service rep and they if I got a Geissele they could send an additional part to make it work. Other triggers would require sending the gun in and they would make it work.

Asked Geissele about it and got back this:
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Thank you for contacting us. In regards to our stance on our triggers in the MPX / MCX, as the industry grows, there are more and more AR variants out there that accept AR15 fire control groups. Each one is different and though we would like to, we have not tested our AR15 triggers with any of them. What we know about our triggers in the MPX / MCX we have learned from feedback from our customers. From the beginning, our customer service representatives have explicitly told people that we have not had any experience with our trigger in the MPX/MCX. We have stated that forum users have claimed to have success but we cannot confirm their success. We have never strayed from this and have never confirmed our trigger work in those platforms, and have always maintained that our triggers were designed to function with a mil-spec M4 carbine. With that said, the MPX has a very fast action, which is why the MPX ships with the trigger bridge, to protect the fire control group from the action. The MPX was designed to be used with the trigger bridge, our triggers were designed to be used with AR15 rifles using mil-spec components. While the MPX and MCX combination will work for a while, it will eventually fail. We want to be clear with our customers on this, and also have them know that we are working on specific triggers for both variants.

Going forward, rebuild kits for our AR15 triggers installed in both platforms will be available. The SSA- MPX / MCX trigger groups are currently in development and will incorporate a trigger bridge to alleviate the current issues. It is slated for release in 2017. Unfortunately the SSA-MPX / MCX triggers are still in development and the price has yet to be determined.

Thank you,
Nick

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The Geissele note is discouraging.

I am hoping someone has some experience with an aftermarket trigger and a G2 carrier group.

THanks in advance.
 
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#3 ·
Just got my MCX back from SIG, I'm Very angry

Hi I'm new here so be patient. I had installed a CMC two stage flat trigger which broke at about 3lbs and it was sweet to use. I called Sig, spoke with a "specialist" and gave him the information about my trigger and he told me QUOTE: "the Geisele replacement is exactly like that" . I asked "FLAT TRIGGER? and two stage" Sig"specialist" , "YES". I shipped it in and got it back in about three weeks TODAY. Just opened the box dry fired and I AM VERY DISAPPOINTED!I can't tell whats in there but it isn't a two stage, it sure as hell isn't a flat shoe and it doesn't even come close to the CMC that I had in it. And just to make things PERFECT with the "UPGRADE" you can't remove the cam pin or the firing pin or bolt because there is a cross pin that holds the firing pin in and that pin has a very small roll pin that holds that cross pin in. So you can remove the firing pin, cam pin and bolt but its going to take a while to do it. NO FIELD CLEANING OF BOLT ASSM. Oh yes, I spoke to another "specialist" right before I wrote this and he didn't even know what a two stage trigger was. I told him that I am very upset and he just mumbled and stumbled out a bunch of BS. I said thanks for the wonderful products and hung up.
 
#5 ·
Hi I'm new here so be patient. I had installed a CMC two stage flat trigger which broke at about 3lbs and it was sweet to use. I called Sig, spoke with a "specialist" and gave him the information about my trigger and he told me QUOTE: "the Geisele replacement is exactly like that" . I asked "FLAT TRIGGER? and two stage" Sig"specialist" , "YES". I shipped it in and got it back in about three weeks TODAY. Just opened the box dry fired and I AM VERY DISAPPOINTED!I can't tell whats in there but it isn't a two stage, it sure as hell isn't a flat shoe and it doesn't even come close to the CMC that I had in it. And just to make things PERFECT with the "UPGRADE" you can't remove the cam pin or the firing pin or bolt because there is a cross pin that holds the firing pin in and that pin has a very small roll pin that holds that cross pin in. So you can remove the firing pin, cam pin and bolt but its going to take a while to do it. NO FIELD CLEANING OF BOLT ASSM. Oh yes, I spoke to another "specialist" right before I wrote this and he didn't even know what a two stage trigger was. I told him that I am very upset and he just mumbled and stumbled out a bunch of BS. I said thanks for the wonderful products and hung up.
Hopefully you got your CMC trigger back. I have no experience with that trigger but it appears to have a tall hammer and should work with the non-Geissele firing pin lock lever. I'd reinstall it and give that a try. If not, I'd ask Sig to supply the Geissele firing pin lock lever and a Geissele trigger for your troubles. Good luck!
 
#4 · (Edited)
Welcome to Sig Talk!! My rifle has run Geissele's fine trigger since Dec-'15, including couple hundred rds with SIG's new Carriage Assembly running both 5.56 & 300Blk - with no trigger issues. I understand their concern with MPX's hammer impacting their original trigger group's disconnector assembly on recoil/reset, but I'm not seeing any wear on my MCX. I guess a 'trigger bridge' type modification similar to SIG's MPX would give us some assurance though.

You may like to review this thread from last month. Looks like Geissele's sticking to the same message we've seen all year...

http://sigtalk.com/sig-sauer-rifles/164218-geissele-trigger-update.html

EDIT: Here are some pics of my Geissele trigger group. This 1st pic is looking straight down at the Geissele disconnector bar there in the center. As you can see, there's no wear or apparent impact marks on this bar's top.



And, here's the back of the hammer, again no wear or impact marks.



Guess I can understand Geissele's caution, given the known MPX issues that SIG addressed with their trigger bridge. But, I'm not worried at all about my MCX trigger - she's doing just fine...

Cheers
 

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#6 ·
I can't offer much advice, because my MCX is my first "AR", but not my first Sig and certainly not my first gun.

Having said that, when I called about 4 weeks ago (I needed a barrel taper cap dohicky to fit my Silencerco Omega) the customer service guy told me to send in my gun. The only problem was that then I couldn't use my Franklin Binary trigger. I declined.

Today, I ordered a 300 Blk out barrel for my MCX, and the guy, Chris (very cool dude and very knowledgeable and nice) tried to get me to do the recall gig as well. I declined again, because of my trigger.

If you talk to these guys, you'll learn that the only mishaps were when the guns were put in VERY strenuous or akward situations, such as loading only 1 round out of mag, etc, really only wierd or unlikely stuations. If you feel the need, do the recall, but for me, I love my Franklin Binary ate freedom to have any trigger on the market. I have no plans to use my MCX in a way that's wierd or would cause those 1% variations in issues. Just my 2 cents.

It's kind of like the EOTECH situation, Lotta military guys won't give them up, neither will I, but report of 1% having issues gets everybody all scared and **** goes a flyin..... if you haven't seen an issue, I wouldn't worry about it. Remington 700, same way. If you practice overally safety, bad things won't happen. Again, JMHO.
 
#8 ·
Boris, I couldn't find your posts, you post alot, haha. Any way you could put a link? I'm curious to read what has happened. I'm not looking to dispute you or debate you in any way, just want to know for future reference. Like I said, this is my first AR and only, so want to make sure I use it in a safe manner.

I've only read of AR'S going off when loading one round, the floating pin can strike the primer and cause a discharge? Hence I never do this. What else should I be wary of?
 
#9 · (Edited)
This is the data I went off of, which is as far as I know of from SIG,

SIG has found through extensive factory testing that in extremely rare instances, not reported in the field and extremely difficult to replicate, a condition may exist causing an unintended discharge. Failure to follow the loading procedures and basic rules of safe firearms handling outlined in the user?s manual has the potential to cause serious bodily harm or death.

So, from what I gather, it's hard to duplicate and not reported from the field, and follow instructions.

I also have a Winny 70 that I did a trigger job on..... if you flick the trigger with your pinky or slam it on the ground, literally, the saftey off, will fire, and a S&W TRR8, when cocked, the same situation.... so I just make sure to not point a loaded gun in an unsafe direction. Along with this I make sure to know all of my guns, as in, when I changed the trigger on my MCX, I actally did bang it around cocked (unloaded), just to see what it's boundaries are.

I'd be curious to see how these things happened when they tested. Notice how they say, "failure to follow basic loading procedures", this is what led me to think the slam fire of one round loaded. Again, just my thinking and could totally be off. I've never had an issue, but I've always used a magazine as intended loaded as intended, and only used about 6 different types of ammo in it. I pretty much stick with Prvi Partizan now. No issueS so far....
 
#10 ·
Thanks for the info guys. Looks like I will end up waiting on this until Geissele comes out with their trigger.

As far as the slam firing problem that started the recall check out this video.



The person in the video claims the problem only occurred with a particular type of ammo that was not SAIMI spec. This is only place I have seen/heard this and I can't verify it, but looking at this guy's videos he comes across as knowledgable, and genuine.
 
#12 ·
Thanks boris!! The first thread wouldn't load for me, but second did. That's crazy that happened! If I understandem correctly, just 300 Blk outs were the problem? Maybe because of ammo choice? I don't know anu thing about 300 Blk out, as I just ordered the barrel last Thursday.

Do they sell military 300 blk? Maybe more regular in specs? Honestly don't know
 
#13 ·
I have a SSA-E on mine. Only a couple hundred rounds so far, but no issues. I'm not losing any sleep over its durability.
 
#15 ·
You know, I go to a particular range every now and again, as it's not on my normal way home usually. Last time I was there I saw a huge sign on the door that said "No Freedom Munitions Allowed", notice it didn't say no reloads or anything. I wondered about it, but since I don't buy from them forgot all about it.

They have an MCX in 300 blk out they rent, wonder if that was why? Next time I'm in, I'm gonna ask just for curiosity sake.
 
#16 ·
I have to share my SIG MCX saga to date. Let me summarize by stating that I sure do wish I had ignored the BCG recall and kept the original which was giving me no problems whatsoever.

When I called SIG about the recall, I told them I had an SSA-E trigger in my rifle and they asked me to send the entire rifle in, which I saw as unnecessary. Ultimately, if they could have better explained what was needed to make a Geissele trigger work, sending it would have been unnecessary.

RDA426 mentions in the original post in this thread "Talked to Sig Customer Service rep and they if I got a Geissele they could send an additional part to make it work." This is correct. SIG actually sent me the part with my replacement BCG, but sent no explanation as to what it was or why they sent it. The replacement BCG was set up to run the factory SIG trigger. The part (I'm not sure of the actual name) kind of looks like it would belong with the trigger group when in fact it belongs in the BCG - in interfaces with the hammer. Not knowing what it was, I set it aside, reinstalled my SSA-E and tried to use it. The rifle would appear to be functioning properly during dry fire, but would result in "click no bang" on the range, though you could see a clear impression on the ejected round made by the firing pin. I thought I had somehow reinstalled the trigger incorrectly.

It wasn't until I found a YouTube video of a guy who explained what the part was and how to swap the part out on the replacement BCG. Apparently you CAN order your replacement BCG with this part already installed - I wasn't given that option. Anyway, I plan to go to the range this weekend for yet another test to see if it works.
 
#17 ·
Can you post a link to that video? I just had a Geronimo trigger installed in my gen 2 mcx and it only fires occasionally. When it doesn't fire the ejected round barely has a dent in primer but when it does fire the ejected shell has a normal strike from the firing pin. Trigger operates perfectly when dry firing. ***!?
 
#19 ·
I believe the piece in question is the "firing pin lock" which is shown in the schematic of the new BCG. The schematic does not show the firing pin lock in detail though. Sig makes a G stamped and a S stamped firing pin lock. The G stamped firing pin lock sounds like the extra piece that was supplied in the thread above for a Geissele SSA-E trigger.

The S stamped firing pin lock works with Sig's stock trigger, the Sig match trigger and Giessele's new MCX specific SSA trigger. I have an S stamped firing pin lock and am currently running the MCX specific SSA trigger with no issues.

As alluded to previously in the thread, Y tube has videos on breaking down and reassembling the post recall/ new BCG which will explain how to take out and reinstall the firing pin lock (which presumably would be the same for both the S and G stamped versions)
 
#20 ·
Well, I must say, I'm glad I read this entire thread. I have a Geissele trigger which I had bought earlier this year at the Great American Sportsman show directly from Geiselle. The original plan was to put it in a 716 that I had at the time. To make a long story short, 716 is gone so I planned on putting the SSA-E in my MCX. Guess I'll be getting a new MCX specific trigger during the BF sales that are going on. Thanks for all the info!
 
#22 ·
SIG still thinks their new Virtus does not need a bridge over the disconnector, but the stock MPX does have the bridge.

The MPX fires 9mm and is intended to be run both with and without a suppressor. Unlike the MCX, the MPX does not have a user adjustable gas system.

Some Geissele SSA and SSA-E triggers broke down in the MCX prior to the new design. Poor maintenance, reloaded ammo and/or incorrect gas settings may have been the cause of the breakdowns that caused Geissele to add the bridge. Geissele is trying to avoid legal liability for mishaps and warranty replacements with the new design.

Bill
 
#25 ·
I got the Geissele for my Virtus, and I'm not terribly impressed with it, especially vs the stock trigger. I'm thinking about a Franklin Binary but I can't figure out if it will work with the Virtus. I've heard from Franklin that there are fewer issues with the mcx vs the mpx, but I just don't know.


Does anyone have any information on this?
 
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