Above is a copy of the SIG service order I received with my MCX. Also included in the package was a new owners manual with an instruction card for break in of the new BCG, sample of Lucas Extreme Duty gun oil and the $50 SIG store gift voucher.

No change was made to the Geissele SSA trigger that I had installed. I did notice a "G" on the firing pin safety of the new BCG installed by SIG. I suspect, but cannot confirm, the firing pin safety is designed to work with the Geiselle trigger, hence the "G".

If a Forum member who received a new BCG, for use with the MCX stock trigger, would be kind enough to look at their firing pin safety for the "G" marking and post a reply, it would be greatly appreciated. The curiosity is killing me, never mind the cat.

The recoil springs may still be removed from the rods, same as previously. However, the new manual does not include this step as part of the disassembly instructions.

Performed a function check and everything was normal. I hope to get to the range this weekend and run it.

Got my MCX back yesterday. FedEx guy just dropped it on my porch and, I guess, forged my signature. Note says they swapped out BCG and function tested with the "SSA" trigger (I have an SSA-E, which is why they told me to ship it in the first place). Took it to the range today. All is working fine, EXCEPT that, if I manually engage the bolt catch (no mag) without pulling the bolt back all the way, the front edge of the bottom of the new carrier is “sharp” enough to lock on the bolt catch. Same happens if I partially withdraw the bolt on an empty mag. I understand the solution to this is to just be careful to pull the bolt all the way back, but, in a serious social situation, “feces occurs.” I don’t like the possibility of thinking I’ve locked the bolt all the way back, inserting a mag, releasing the bolt, and thinking I’ve chambered a round – but I haven’t, because the bolt didn’t pick up a round. I’ve had a few inexpensive ARs in the past that would lock back on the carrier edge, but I’m fairly certain the original MCX bolt didn’t.

Mine were both received by Sig yesterday. I have Larue MBT triggers in both, I'll post back with info on what firing pin they return with and what trigger.

I received my new BCG but now my stock trigger is much worse (dry firing only). Is there an upgrade available from anyone?

And, my bolt locks half way back if manually engaged too. I probably would never had noticed this if I didn't read the post above. Is it a problem in operation for anyone?

I have two MCXs and both were registered the same day.. One is 556 the other is 300 Blackout. Got a small box and sent it back to Sig 14 days ago with the 300 Blackout carriage assembly. But two days later got an emai from Sig saying I need to send back the whole MCX. At that time, I started to think the whole thing might not be well planned and got my worry grew.

Checked some feed backs on the webs and found some negative results after owners got their new carriages installed and tried. My worry grew further.

Thus I decided to hold shipping back the carriage assembly of the 556 until Sig sort them out. My 556 MCX runs perfectly.

I registered for the Carriage Assembly upgrade in mid January via phone in because I had Hiperfire ECL triggers installed in my MCX PSB and MCX Rifles. Sig sent boxes with instructions to send back all 3 firearms about a week after I called in. Sig received all MCX's on 31 Jan. I just got them back today (Happy Valentine's Day, Love Sig) with Sig installed Geissele Triggers and upgraded Carriage Assemblies. Sig returned my all Hiperfire ECLs to me. All the Geissele triggers measured an average of just under 5 lbs. on my Lyman gauge. I will have some time to go to the range later this week and provide an update on performance and function when I have something to report. No complaints so far as to how this upgrade program has worked out for me from a value perspective and turn-around times as I have Sig approved and installed Geissele triggers in my MCXs, I got my Hiperfire ECLs back to install in future AR builds, and I have $150 of Sig Store Bucks for my "troubles". So far, so good.

quote:

Originally posted by Redhookbklyn:

No change was made to the Geissele SSA trigger that I had installed. I did notice a "G" on the firing pin safety of the new BCG installed by SIG. I suspect, but cannot confirm, the firing pin safety is designed to work with the Geiselle trigger, hence the "G".

If a Forum member who received a new BCG, for use with the MCX stock trigger, would be kind enough to look at their firing pin safety for the "G" marking and post a reply, it would be greatly appreciated. The curiosity is killing me, never mind the cat.

It appears the G firing pin block would be for a Geissele Trigger.



https://www.youtube.com/watch?v=c-4wo2JZ8Ko

So what is the risk if down the road I decide to use an aftermarket trigger in my MCX with the new BCG? Will it even work?

quote:

Originally posted by }BuLL:
So what is the risk if down the road I decide to use an aftermarket trigger in my MCX with the new BCG? Will it even work?

Some hammers may not disengage the firing pin lock.

My Question to Geissele

I understand that you are marketing a special trigger for the SIG MCX riffle.

I have had the Bolt Carrier upgrade done from SIG and now want to purchase the trigger assembly shortly.

Thanks
Roy

Their Answer!

Good Afternoon Mr. _________,



Thank you for your interest in our products and for contacting us. We do have a Sig trigger in R&D and it will be released in 2017. At this time we do not have an anticipated launch date or price point. The best way to be notified of new product launches is to sign up for our newsletter. At the bottom of the page I will link below, just above the grey bar at the bottom, you will see “stay connected” on the left hand side. To the right it says “email address,” enter your email address in the text box and click the arrow. You will be notified of new product launches.

https://geissele.com/customer/account/login/

Please feel free to contact us with any further questions.

Thank you,

Dan

Thank you ontmark.

quote:

Originally posted by Redhookbklyn:
If a Forum member who received a new BCG, for use with the MCX stock trigger, would be kind enough to look at their firing pin safety for the "G" marking and post a reply, it would be greatly appreciated. The curiosity is killing me, never mind the cat.

Mine does not have the "G" stamp.

quote:

Originally posted by }BuLL:
Thank you ontmark.

quote:

Originally posted by Redhookbklyn:
If a Forum member who received a new BCG, for use with the MCX stock trigger, would be kind enough to look at their firing pin safety for the "G" marking and post a reply, it would be greatly appreciated. The curiosity is killing me, never mind the cat.

Mine does not have the "G" stamp.

Thank you Bull and Ontmark.

Both of mine (11.5" SBR and rifle) showed up today with Geissele triggers. My Larue MBT triggers were packed in baggies. The charging handles they were shipped with remained. Overall I'm happy. 2 week turn around, two free triggers I can use in other builds and $100 to spend.

Got my upgraded BC back today from Sig. It has the G on the firing pin lock, and the part description on the bag that the assembly came in included "GEI" at the end, which I assume stands for Geissele. I never had to send my entire gun in, but when I called for the recall, I told them I had a SSA installed, so they knew I had one. I assume you only get the G version if they know you already have one, or if they put one in if you sent the entire gun.

Kind of pissed that people who had a non-Geissele aftermarket trigger, got a free one, and also got their old one back for use in something else. In other words, got a free trigger, while those who already had one got nothing. Thanks Sig!

Also noticed that the rear recoil spring clip is still polymer, and the springs aren't captured (you can still remove them from the clip like on the original). The difference is that you now lift the entire recoil spring assembly off at once so there is no longer a need to disconnect the clip.

BTW, anyone else able to remove the recoil springs without pushing out that tiny firing pin lock pin as shown in the video? That pin is already in place during reassembly, so I figured if it goes back together with the pin in, it should also come apart with the pin still in. Tried it by lifting the firing pin lock, and sliding the op rod assembly out sideways (i.e. reverse the assembly instructions), and it worked fine. Don't see a need to ever mess with that pin.

I received my MCX-P with a Geissele trigger back with the upgrade yesterday. There is a "G" on the new firing pin lock. It was a 2 week turnaround. The upgrade passed my initial function check with Lancer and Pmags and a variety of ammunition. Field stripping is a bit different now as shown in the video above. And yes, I can pull it apart without removing that little pin for the firing pin lock. I am happy.

It seems there is now a change in SIG's process for doing this recall/upgrade. Yesterday I received the new BCG for my MCX carbine. I have a Geissele trigger in that MCX as well but in this case the CR offered to have me return the original BCG and they would send the new one set up for my trigger. I installed the new BCG, with the G on the firing pin lock, and all seems well. Only 10 days total turn around.

I am in the middle of the parts exchange right now and may have missed something in all the posts above.

Does it require a certain trigger lock bar to be able to work with a certain "Guys-Lee" trigger? Will I need to be sure to buy the correct trigger and then get the "G" locking bar from SIG?

I do think I'll be replacing the factory trigger. It is not all that great. Once you fire the SSA you don't go back!

OBTW, the nice lady at SIG Customer Service mentioned that they would be shipping a new hammer also. Can it be that the new safety bar doesn't work so well with the pre-recall hammer?

Bart Noir