Finally have mine how I wanted it from the get-go:


I was intrigued by chaosrob's post about their ILWT replacement barrels and installation vise block. Instead of destroying (cut and rethread) the original 8" barrel, you remove the barrel from the gas block, and replace with theirs. When I ordered mine a couple of weeks ago, they were offering a 4.5" barrel, with tri lugs and also threaded (1/2-28). I see that between then and now they started selling a 4.5" without the lugs, as well as a threaded 6" barrel.

Installation was a mixed bag. The vise block made it easy to punch out the barrel pins and remove the flash-hider. I tried using a "9mm squib remover" brass rod to hammer the barrel out. On my gun, it wouldn't budge at all. Not sure why, I possibly may just not have had the right tools, or used insufficient force. Keep that in mind when watching the installation video that was posted. That said, it's certainly not a problem with the ILWT vise block. It's my tools, or how SIG has assembled the original barrel/gas block.

Instead of looking for larger-diameter brass rods or other tools to get the barrel out, I resorted to sending it back to ILWT and have them change it out for me. After same-day service, here's what came in the mail a couple of days later:


Reassembly was quick. Barrel/gas block assy held in upper by 2 bolts:


There's still lots of room under the handguard with the Octane45 installed:


All-in-all, very happy with the product, and the service I received. From the looks of it, I may be able to get the can a little farther under the handguard by using a tri-lug adapter (instead of the piston/fixed spacer that's on it now).

Now off to shoot it

Chaosrob is a good guy IMO....

Your new set up is awesome.

Yeah it was an 8" with folded brace. I had the barrel cut to 4.5. I'll try to see if it fits with the suppressor on it when I get home.

So I see a couple of online stores have MPX-K-9-T-KM-SBR in-stock. May be we will see 4.5" pistol soon.

Just called Sig. 4in barrel on order since August, no eta. They recommended that I call by in several more months.

quote:

Originally posted by nreno88:
Just called Sig. 4in barrel on order since August, no eta. They recommended that I call by in several more months.

I talked to SIG CS two weeks ago, and he said 4.5" barrel assemblies (barrel, gas block, flash hider) would be shipping by May 2017. They offered me a 10% discount to pre-order ($539).

quote:

Originally posted by d2randall:

quote:

Originally posted by nreno88:
Just called Sig. 4in barrel on order since August, no eta. They recommended that I call by in several more months.

I talked to SIG CS two weeks ago, and he said 4.5" barrel assemblies (barrel, gas block, flash hider) would be shipping by May 2017. They offered me a 10% discount to pre-order ($539).

I think I may be able to live with May. Hopefully I will not be too far down the list. I am not looking forward to taking off another one of those flash hiders.

You guys are better off buying one of the aftermarket options or having your barrel cut. Sig promised me a k barrel in December of 15, and they're still just a pipe dream.

I just saw that LuLa now has a MPX magazine loader available. Anyone feedback and what else is out there to assist loading these mags?

quote:

Originally posted by 10x Sniper:
I just saw that LuLa now has a MPX magazine loader available. Anyone feedback and what else is out there to assist loading these mags?

Just get the maglula, or make a push-loader out of wood. I made one out of some plywood that worked shoving 8rds in at a time using a bit driver as the pusher. But the maglula is the way to go now that it is available.

Well it has taken me almost a week to get through this complete thread. I started out wondering what triggers I could use. It looks like Geisslle is out for a while but I never heard of one thing. Has anyone used the original sig disconnector and bridge with their upgraded trigger? I installed a ALG Defense ACT trigger without the bridge today. I'll see how this works.

About 3 weeks ago the right side latch of my 2nd Gen MPX charging handle went flying down range, unrecoverable. I emailed Sig the picture and they say they sent me a new one but it shipped USPS without tracking.

2 weeks later and the replacement still hadn't arrived. The gun was still functioning so I took it shooting again this weekend.

This time the left side latch failed as well. The MPX would chamber a round and then just click, it wasn't going all the way forward into battery. Upon closer inspection the left side roll pin had worked it's way loose, was getting hung up on the receiver, and was bent. The pin then broke and the left side latch fell off. That ended the day with the MPX as every time you pulled the trigger the charging handle now flew out towards your nose.

This time Sig sent me a new one via FedEx, hopefully I'll be back up and running this week. So check your charging handle to see if the roll pins are walking out, as they will cause the MPX to malfunction if they walk out far enough to contact the receiver.

I have about 1000 rounds through my MPX. Still no problems with the standard Geissele SSA trigger that I had purchased/installed while Geiselle was still saying they would work fine in the MPX.

quote:

Originally posted by Brett B:
So check your charging handle to see if the roll pins are walking out, as they will cause the MPX to malfunction if they walk out far enough to contact the receiver.

My charging handle on a January 2017 gun appears to have staked roll pins.

I called them when the left side wouldn't work. Got my replacement I 3weeks. Great customer service.
Tommy

The replacement charging handle arrived and it looks identical to the one that failed. There are no signs of the pins being staked on either of them. Guess I will have to keep an eye on the replacement too. The first one already gouged up the receiver pretty severely.

Should be easy to accomplish with an automatic center punch or even a finishing nail and hammer but I was never one for fancy gunsmithing.

This message has been edited. Last edited by: jmbrowning,

quote:

It looks like Geisslle is out for a while

Why would Geisslle not work? Ive used CMC and now have a Franklin Binary trigger in it.

They used to say you could use their triggers in the MPX but changed and said they are coming out with a specific MPX trigger.

The problem is the hammer is hitting the disconnector which is why SIG has the bridge in place. Most disconnectors are a little too tall for the bridge to work. So some modify the bridge to use aftermarket triggers.

I just stuck a 3.5# JP hammer spring in mine. It's still a little gritty, but feels better.

quote:

Originally posted by Phelen_Kell:
They used to say you could use their triggers in the MPX but changed and said they are coming out with a specific MPX trigger.

The problem is the hammer is hitting the disconnector which is why SIG has the bridge in place. Most disconnectors are a little too tall for the bridge to work. So some modify the bridge to use aftermarket triggers.

I just stuck a 3.5# JP hammer spring in mine. It's still a little gritty, but feels better.

I bought a SSA trigger from the because they said they would warranty it. If it breaks...they will replace it. Hopefully they'll still replace it if anything happens. The SSA was a great improvement to the MPX trigger but it wasn't all that impressive to me. Now the webpage says their triggers are to be used from ARs only. MPX trigger coming out soon.

Thankfully with the popularity of the PCCs there will be a bit more in aftermarket support.