r/MPX

Not sure what will come of this requirement in the future. But approved today. Took 33 days to a trust.

I have a Reptilia charging handle and arisaka indexer but any other upgrade recommendations?

I am looking at suppressor now, early front runners is wolf man, exigent Rico309, and who knows. I will want to tuck.

GEN2 MPX 8in with ArcFire 45-90 V2

I’m having an issue where I cannot get the gun to rack past 3/4ths of the way.

The FRT function tests fine inside of the lower, but it isn’t working properly with the upper because it’s not charging correctly.

The Bolt catch isn’t working as well as a result of how far back the bolt goes as well.

It slides but it’s stiff, I worked it a little until it was easier to move.

I tapped the pins in with a medium amount of pressure. It took a little force to set them, but once it was in, it went in pretty smoothly. I tapped it a little more until it was closer to being flush.

I cleaned the gun after picking it up, it has maybe 50 rounds through it since

Semi Automatic works, but FRT mode is running poorly. I can feel the trigger wanting to reset but since it’s not traveling far enough to reset it every time then it’s only functioning like semi.

I had a few 2 rd bursts in frt mode and one 5 rd burst but it was jamming fairly often between them

Any ideas on how to get this out and tune it properly? Thanks in advance.

Does anyone know if this upper receiver from Sig comes with the 2 holes on the bottom for the trip bar install? My MPX does not have the 2 holes and wanting to buy this if it does

First time trying this out. Definitely took a couple tries on a couple drills but overall felt pretty good and learned what I need to improve on. Highly recommend.

Drill details:
GBRS standards (all 7 yards)
1 shot A zone from low ready (1 sec)
1 shot A zone from high ready (1 sec)
Pistol bill drill from holster (3 seconds)
Rifle bill drill from any ready (2.5 seconds)
3 to body, 2 to head from any ready (2.5 seconds)
1 reload 1 - rifle (5 seconds)
1 transition 1 - rifle to pistol (3 seconds)
Check drill (12 seconds)

Pic for attention.

Long story short… finally got this thing sbr’d last month and now I’m shifting my attention to this platform after I got my new SP5k out of my system. I have the Sig Minimalist stock on it and I am honestly not loving it… the length of pull is so short (I’m not even a big or tall guy). The original brace that came with it is actually about .5”-1” longer because the brace part is so thick, that’s actually the perfect length, I just hate the fact how the factory brace swivels and doesn’t stay still. Not sure if the Sig Minimalist Plus Stock would make a difference in feel, maybe it just feels short because it’s smaller against my chest? Feels like only the very pointy end part of the stock is pressing against me? Can anyone chime in? I bought the minimalist stock from EuroOptics, the return policy seems like such a hassle and I’d lose more than I’d like with return shipping and restocking fees (if they’d even accept it) so I’m stuck with it.

My question: I do have the SB Tactical collapsible brace, I bought it very early on and have been shooting it with the SB collapsible brace for the 95% of the time I’ve owned this gun. Is the actual Sig collapsible stock much more different than the SB collapsible brace? Worth it? Any pros over the collapsible brace? What I’d like to avoid is to pay $250 only to have it be more or less the same as the sb tactical collapsible brace, only just to say “I have an MPX-K SBR”….

Attachments:
-Holosun AEMS Red Dot w/ low rise mount
-Sig Handstop MLOK (KIT-MLOK-3329)
-Sig Minimalist Stock (the non-plus one)
-Magpul KOE+ 2 grip
-ILWT TriLug Muzzle Adapter
-OCL Lithium 9 with Rugged RU3 TriLug Mount

Answers to potential questions:
-I’ve only shot it once with the ILWT TriLug muzzle to rezero, still semi accurate and didn’t notice a huge change in groupings at 25yards but I’d like to do more testing before I can give a definitive answer (I heard mix reviews but for $60ish I said what the the heck)
-Haven’t shot it suppressed with this set up, waiting to really see if the ILWT muzzle is worthy enough for me to keep it on before I go rocksetting it

Reached a stopping point, not much more I can do.

Just waiting to swap the surefire can out with the rugged obsidian once it arrives.

Not US-based. Can't find reliable suppressor suppliers out here in the PH.

Hey guys, quick question as I’m seeing conflicting reports online. I want to FRT my MPX of course, and I want to upgrade the trigger at the same time to a Timney trigger. Is all that I need to get is the AS DESIGNs MPX SLIP TRIP KIT REV 2, and the ARC FIRE TIGGER V2?
Is it just those two items in addition to a better trigger? I’ve heard people complain on the rare breed quality too.

https://activesafetydesigns.com/mcx-mpx/mpx-slip-trip-kit-rev-2/

https://activesafetydesigns.com/ar15/arc-fire-trigger-v2-non-ambi-kit-0-90-180/

Had struggled for a while with the factory barrel, running suppressed. Went ahead and bought the aftermarket barrel, and ran it with a fixed mount.

Absolutely wonderful. Great accuracy, and the adjustable gas plug works perfect. Gassed the system to where it just barely cycles reliably, and the felt recoil is better than anything I have ever ran.

Just came here to say that if you were on the fence about buying the barrel, to go for it and not look back. I should have done this a long time ago.

Discuss...

Saturday I picked up my MPX-K and I’m waiting for a few of the other parts to come in. I have an MRO and RMR HD but ordered a scalarworks leap for both. Then I got to thinking about the new Holosun promax coming out and thought that may be a solid optic for this build. So I decided to put AI to work. I also have a Midwest industries 8” hand guard coming as well as a Rico309. I was curious what all this would look like so I turned to AI to help me get a visual. My stock is the Kate Moss so that’s really the only thing (for the most part) AI got wrong, and the VFG.

But I’m really curious to see how many people decide to run the new Holosun promax on theirs since it’s a good bit bigger than the RMR HD.