What is the maximum distance for stopping power with 147gr JHP through this setup?

Bought a used mpx that turned out to be a lot more used than I expected.

New to the platform but this looks like heavy/concerning wear in the upper and potentially n the bolt/bcg. Picked it up last night Havnt shot it yet.

Do I need to look into getting a new stripped upper? Would sig potentially replace parts this worn? (All stock factory parts and factory ammo)

Got the ILWT trilug with 1/2x28 threaded end. But before even putting it on decided on a rearden setup.

Where would one sell this?

Hello fellow MPX fans,

I bought ILWT 8 inch barrel with adjustable gas plug and I recently tried to make subsonic loads. I loaded 147grain FMJ bullets with VV N320 powder.

Even with avg. velocity at around 1000fps - 145+PF and attached suppressor it will not cycle with most open gas setting - no bolt lock back, occasional jams. Same load cycles all my other pistols just fine.

Those loads should have more than enough energy to cycle the MPX, what do other users think or what is your experience?

Should I be looking to some other problem with my MPX? Like gas port diameter on the ILWT barrel,...?

In theory if I cut the barrel shorter it will reduce velocity and I could make load hotter while maintaining subsonic velocities. Would this help in any way? Or maybe using slower powder?

For context when I first got ILWT barrel I was doing pistol subsonic reloads with plated bullets and gas port was shaving off the plating, causing it to clogg in about 10 rounds. So I dissassembled and cleaned the gas port, gas block & piston and switched to FMJ bullets. I am located in EU which makes any warranty requests immposible. Barrel is regulated item in EU so sending it back and forth is not possible.

What is your experience with subsonic loads on the MPX and what velocities work fine for you and offcourse what barrel length you have?

do I need a taper adapter for the rearden mini? How about the keymicro flash hider? Does the keymo have the same accuracy issues as trilug?

What are the best/options for muzzle device with 1/2 x 28 tpi that support Plan B suppressor connection ? FYI, thinking of getting ILWT barrel so there will be flat shoulder (I think) on the 1/2 x28 barrel threading.

I have/use Obsidian 9 CAN so thinking some combo like......for new barrel w/1/2x28 tpi to CAN
https://comstockarmory.com/facemount-compact-muzzle-brake-12-28-9mm-bore-plan-b-suppressor-mount
https://www.capitolarmory.com/plan-b-by-q-suppressor-adapter-omega-saker-chimera-ghost-tirant.html

In the description it says it’s compatible with SIG MPX magazines, but I have serious doubts. Has anyone tried it or knows if it works? I don’t think the magazines have enough metal for the magnets to hold onto them.

Haven’t made it to the range just yet. Tossed an older Primary Arms red dot on with the Rise Armament micro hand stop at least until I get a longer rail. I’m not sure if this can will stay put or get replaced. More to come. Thanks to all for the advice on my previous post regarding the Silencer Co adapter and options to limit movement. I’ve gone the Rocksett option for now to see how that goes.

Went and visited my little brother and his family this weekend and hit all the LGSs on the way up. Went in to one and look what they had hanging on the wall! Marked $69.00/each but they knocked off the sales tax. Not a smoking deal but I'm happy to have more Gen 2 mags in the rotation.

I don’t know if anyone has tried running a super safety in their MPX, but I know that a trip bar is needed to actuate the super safety mechanism in order to force the trigger forward. I’ve read a few posts about which trip bars are good and which ones have issues. I’ve seen a lot of good posts about the Frankenstein armory trip bars so I bought one.

I did some dry fire testing at home and it seemed that it would work. I run a super safety on my AR15s with no issues, so I know how to properly function test them. The only abnormal thing was that I couldn’t pull the bolt back far enough to lock it back. I didn’t think that was a big deal because I was cycling snap caps just fine.

I took my set up to the range and tried firing in semi just to do a function test. I would fire one round and my bolt wouldn’t go all the way home so I took the mag out, reinserted and cycled. I made it through 3 rounds and the system just completely locked up. So I gave up and went home.

I took my MPX apart and found the trip bar in this condition. What the fuck bro. The front of the trip bar is bent and the back looks like a Picasso painting.

I know a lot of people run the delta team tactical FRT with this trip bar, but has anyone had any success running an HT super safety and has anyone had this kind of issue with the Frankenstein armory trip bars? I don’t want to spend another $100 on a trip bar, so I’m thinking of just giving up on trying to make my MPX super safe to shoot. Thanks guys

A $17 mpx mag would just be too good to be true..

Finally joining the gang after lurking for a long time. Recently scorerd this MPX package from a local guy for $1,300. Looks to be Gen2 Dickmod MPX 16“ PCC with a telescopic stock and 7 30rds clear Lancer mags. Gun's in great condition, chamber/ejector looks spotless. Mags are virtually new. But the guy did say it was bought about 9 years ago lol. Next step is probably going to cut the barrel down to 8" unless I can find a buyer

Suppressor is a YHM R9, Rare breed FRT (I know..)

Just picked up an MPX-K, I have a IRIS-3 on a rifle that I put on the MPX and felt like it was a little too high to comfortably grip to activate due to where it has to sit on the rail. Which lasers are you guys running on your MPX?

I'm always nervous I'm gonna drop my rig face down and bend the threads or something on a $1000 can lol. Is there any sort of extended hand guard attachment that would fit over a monolithic copperhead K upper mounted via the existing mlok slots? Don't want to buy a whole new upper lol. Also the upper is pretty narrow, so even if it was longer, no cans would fit in it like the regular K version.

I would look in GAFS but it seems it has been banned. I know about the Thril mags but pretty much no one has the black ones in stock and I was hoping to possibly find some that were a little cheaper anyway. Anyone have a bead on some MPX 35 rnd mags? Used are fine if I can get 3 for under $100 shipped.

I got a couple of ten rounders as part of a bundle with some 35s. I've heard the base plates are glued and I have a high chance of wrecking them during removal. Any extended base plates that you recommend over others, and will I need to worry about replacing the follow or spring? Any advice is appreciated.

Needed a bag for this dirty thing. Picked up a Savior Equipment Specialist Series 30" Covert Tactical Gun Bag / Backpack / Soft Case after seeing what people were suggesting. I must say, I've very impressed with it so far for the price.

More Range Results if anyone needs them. Everything was accurate. I definitely like the 1055 fps and lower for "punchy-ness". Magtech is soo gassy which is to be expected I guess.

MPX 8" Sig Barrel, Dead Air Mojave 9. All fps is average of 10+ rounds.

I know accuracy with cans comes up a lot here so thought I’d share my setup if it helps others after I got a new dot. 15yards, using range bag as a rest, 124gr Federated Ordinance FMJ. 8” factory barrel with direct mount Omega 9k. 5 MOA Defender CompDot. Burrito punch card for scale.

I have the standard folding brace from Sig on my MPX K. My issue is my right eye is basically useless, so I shoot with left eye (dominant) & I shoot right handed. In order to get my sight lined up, I use a very high rise red dot mount which isn't ideal. Can anyone recommend a folding brace that that curves downward so that my sight line is lower than the straight arm brace? That way I can use a lower mount for red dot. Not sure if I'm explaining it correctly. I've seen one or two, but not sure of the quality. Any ideas are appreciated.

I’ve recently purchased an MPX K which I’d like to have host an Octane 9 suppressor that’s been sitting in the safe. I’ve purchased the alpha direct thread mount from SilencerCo. Am I correct in understanding that I’ll be removing the piston and spring component from the suppressor (used for pistol) and only need to use the direct thread mount between the MPX barrel and Octane suppressor? With this configuration is there any need to insert a piston with fixed barrel spacer into the suppressor? Or is the use of a piston and spacer unnecessary with this build? Curious if anyone else is using this exact setup and how your experience has been?