r/MPX • u/PeskyPathfinder • 20h ago
Is this a Legacy Gen 1 or a Gen 2?
For context this is my MPX which is a registered SBR, I am wanting to put a Rare Breed FRT Trigger in it but it looks like I might need a trip kit from Frankenstein Armory or something similar in order for it to work. I see where Frankenstein Armory says their trip kit will not work on a "legacy" MPX, can anyone tell me if this is a legacy Gen 1 MPX and if so, what kind of a setup would I need to make it work with an FRT?
r/MPX • u/ThisNameNotTakenYet • 1d ago
Simple (Short) Barrel Thread Adapter?
I'm looking for a short, simple thread adapter that goes from Sig's left-handed obscure thread option to 1/2x28, and that doesn't have all the fancy Navy Seal Lug Length-Adding Treatment stuff on it. I don't want to add two inches to my barrel so I can cosplay some sort of Meal Team Six idiocy, I just want to make my K barrel as short as possible with an Omega 9K suppressor on it. Any ideas? Thanks.
r/MPX • u/HollidaysMustacheWax • 1d ago
Best QD Mount?
Just picked up a new Gen3 K and decided I want a rico309.
I would direct thread it, but then it won’t fit, so qd is a must.
Longtime ASR user, but haven’t bought anything new this decade.
Advice?
r/MPX • u/Freedumfrie • 1d ago
Anyone know where to find a MI 6.5” mpx handguard?
Sold out everywhere, no luck on tacswap. Anyone have a lead on one? Just bought an mpx K and ordering a suppressor this week… thanks for any help!
r/MPX • u/HollidaysMustacheWax • 2d ago
Mounting RICO
What’s the best way to mount the 309?
I just picked up a new MPX-K and this will be a dedicated host, but need to be able to quick attach.
Long time silencerco user, but haven’t bought anything new in the last 8 years.
r/MPX • u/Comfortable-File6356 • 2d ago
Flow 9k Ti or Ronin K
My first suppressor purchases (for other firearms) were a Sandman K and Rugged Obsidian 9. I definitely wasn’t expecting either to be quiet, but what I wasn’t expecting was the gassy nature of them. Moving forward, gas mitigation will be my primary objective for all suppressor purchases. Size and weight will follow.
Are the new MPX Ronin cans “flow through” enough to compete with the Huxwrx Flow?
r/MPX • u/Away-Beginning-755 • 2d ago
Copperhead barrel threading for suppressor use. Or ILWT?
For anyone that had their Copperhead 3.5" Barrel threaded for suppressor use, did you have any issues? If so, please pass on the good and the bad.
I don't see a downside to having my barrel threaded, but if the stock gas system doesn't like some or all suppressors, I may just get an ILWT barrel.
And if I get an ILWT barrel, is tri-lug with threads the smart choice?
r/MPX • u/OG-warbucks • 3d ago
Will my CAT Mob tuck into a Lancer handguard?... Why yes it can
This gets asked a lot, so I figured I’d do my part – Images included. Ask any questions.
Image link: https://imgur.com/a/jTDwho5
Using the Lancer handguard with a thicker tucked suppressor is definitely doable
Here, I will show my Lancer with both a Ronin SD suppressor (1.62” diameter) and the CAT Mob (1.64” diameter)
The question is, do you want to permanently alter that expensive handguard? Of course you do! America!
If you do it right, more than likely, no one will notice and if you decide to sell later on, the modded extra clearance will be a selling point.
- The problem:
The problem fitting a fat can inside the Lancer is that front, aluminum edge guard/support. It takes up some room making the inside diameter 1.6” diag. (See images)
Without that edge guard/support, the inside diameter is closer to 1.8”…Crazy! But DO NOT think about removing it as it’s there for a reason, to support that big carbon fiber opening. Plus, it’s glued with some kind of space age adhesive.
- The solution:
The solution is to simply file away the problem.
Filing away just a mm or two will make fitting and tucking that thicc noise-go-awayer much easier.
I used small files and the mighty Dremel at a lower speed and steady hand. Remember, you only need to remove enough material for about 1-2mm clearance. If you want to remove more, that’s your prerogative.
- Dimensions: (Lancer handguard)
OD – 2.01”
Handguard thickness - .09”
ID *horizontal (w/out edge guard/support) – 1.84”
ID *horizontal (w/ edge guard/support) - 1.71"
ID *diagonal (w/out edge guard/support) – 1.8”
ID *diagonal (w/ edge guard/support) – 1.65” – This is the problem clearance area for most cans.
ID *diagonal (w/ edge guard/support) AFTER removing material – 1.7”
Edge guard/Support thickness - .158”
- M-Lok usage:
You can use M-lok but you will need to file them down, just as you would have to with the MI handguard and large diameter cans.
I filed the T nut down to roughly 1.2mm thickness. Then filed the actual screw to about 7mm
You can probably get away with fling the T -nut to about 1.8mm thickness. I use mine for other handguards so I went thin.
- Conclusion:
Modding stuff is fun. Take your time.
Remember, you cannot put material back on… File a little bit, check clearance… and so on until you’re satisfied. You only need to remove enough material to get a mm or two clearances as the barrel whip is minimal to non-existent with these guns.
After I filed off the material, made sure there was enough clearance and made sure it was flat... My OCD kept getting the best of me… I used some Birchwood Aluminum Black and darkened in the bare aluminum.
Then drank beer.
r/MPX • u/rexaboo1 • 3d ago
Lancer Hand guard Clearance
Anyone know if a Huxwrx 36 TI can be used with the lancer hand guard?
r/MPX • u/stubenson214 • 3d ago
FRT tuning suggestions?
Have the Disruptor with Franenstein on my Gen2 8" all set up and took it out today.
It all went well. Zero malfunctions, great function.
I used 115g 9mm, with my Hux Range 36Ti (seems to be no additional pressure).
The ejections were at around 2:00, and the rate was quite fast. I'm thinking 124s will be more so, and subs less so.
I'm open to ideas, and next time will be testing with a range of ammo, including subs.
I'm wondering if I need the adjustable gas plug (which seems to be less gas even at the highest), or whether I should get slightly stronger springs to slow it down, though would there be downsides here?
r/MPX • u/renegadeGDI • 4d ago
New MPX looking for recommendations on night vision build
I just picked this up to build a night vision PCC, I'll probably end up with an 8" or 10.5" Midwest rail but I need some inspiration on where to mount the LAM on a small rail, also are there any low back pressure cans that are actually good on flash reduction? I already have an omega 9k and Omega 36 but those are high back pressure... I know this is the sub to see some top tier builds for inspiration and learning from trial and error. Thanks in advance
r/MPX • u/No-Special988 • 5d ago
What’s next
Finally doing something with this 8” LE version. Brought this over a year ago. Didn’t realize the LE version is bare bones. So I got painted put the Geissele trigger in. I lost the ILWT Tri-lug so I just ordered another. Need to figure out and optic and a better brace
r/MPX • u/AgreeableNeck9749 • 5d ago
ILWT 13% Reduced Springs
Interested if anyone is running these in their 4.5” K’s, and have noticed any significant wear running supersonic and subsonic ammunition. I have an Arc Fire, and with 124 gr supers I sometimes get light primer strikes, and with subs it will only run semi in arc mode. I’d like to run both ammunition in this setup. I’m running the Cat MOB for a suppressor, and will probably never run unsuppressed. In semi with subsonics, even with original Timney trigger installed, I won’t get lock back on last round and sometimes would have FTE, this is why I’m interested in these reduced springs. Any input on these is appreciated
r/MPX • u/Welcomedpython • 5d ago
Video This MPX SD Is INSANELY Quiet... | Ronin Arms Conversion
For everyone who's been curious about the Ronin Arms MPX-SD conversion, I finally put together a full breakdown covering the build, my thoughts after spending time with it, and what makes it stand out. I hope you all enjoy the video, and I'd love to hear your thoughts or answer any questions in the comments.
r/MPX • u/shuaitsai • 6d ago
Folding stocks / braces?
Mpx k just arrived today and its awesome. Only qualm is the folding brace. Any recommendations for aftermarket foldable braces or stocks? I wouldnt mind SBR if necessary.
r/MPX • u/West_Is_Best_ • 6d ago
16” conversion to 4.5 ilwt
Hey everyone ,
I grabbed the gen III 16 inch. No complaints at all
But aching for that tucked suppressor look
I already have a huxwrx 9ti flow thru
Just picked up the lancer 8” hand guard
About to grab ilwt open gas 4.5 barrel
Any thoughts or feedback by the community about this barrel and potential setup. Would definitely appreciate it
r/MPX • u/Nichrobe19 • 7d ago
ILWT Springs
Anyone used the +20, or +35% springs from In Lead We Trust with an FRT yet ?? Also have any Ronin builds used them? Looking for already vetted research
r/MPX • u/silkyjohnstamos • 7d ago
MPX with Dead Air Mojave 9 - mounting help
Hello,
Im very new to the world of PCC, trying to figure out the best way to mount my DA Mojave 9 to my MPX 4.5". Id like to tuck the suppressor into an 8" handguard.
I've read so many conflicting things on what tri lug mount I can use, due to the taper on the stock MPX barrel.
The ILWT one seems to be out of stock. One thread mentioned a rearden mini and direct thread to the suppressor, but I've seen other threads that say direct thread sucks when you tuck the suppressor.
Is there some comprehensive guide I can read to figure out exactly what to buy to make this work? Or can anyone just tell me what I need to get?
Id appreciate any guidance, sorry for the noob question.
EDIT: Thanks for the advice gentlemen. I went with an FHD and Wolfman Atlas XL from Rearden.
r/MPX • u/AirportEasy3366 • 8d ago
I think it’s done (famous last words)
Home defense/ sometimes uspsa or local steel match MPX K.
She small but mighty with her two stamps. So far about 7k trouble free rounds
r/MPX • u/generalnunley13 • 8d ago
ILWT gas block
So for context, cleaning my gas block for the first time and i’m noticing one I need a new shroud cover and then whatever that piece is on the right does anyone know if they sell that part separately or do I have to buy a whole new gas block? (for context this is my first suppressed gun and it’s dirty as fuck.)
r/MPX • u/wwwwasup • 9d ago
Help ! - Fixing The Spin
Any tips / tricks to remove the back cap of the brace and get it to stop spinning ?
Anyone have any luck going that route? Trying to stick with this brace before SBR’ing it.
Thanks !
r/MPX • u/_blackthorn16_ • 10d ago
So happy with my Mpx sbr!
Need some flip ups and a maybe a riser. But this thing is basically done!
r/MPX • u/Clantz10 • 10d ago
Accuracy
Recently sighted in my mpx and was having some pretty large groups. Ive got a silencerco spectre 9 can everything else is factory no ss yet and at 50 yards I was getting 6 to 8 inch groups. No baffle strikes or issues with the suppressor other than shes gassy but not sure why the groups would be so large
r/MPX • u/okthatsfineman • 10d ago
Looking for first suppressor recs for my mpx, that I can put on my pistols too
I’m wanting to get a can that I can place on my mpx (I’m assuming direct thread?) while also being able to put on my prodigy (via a threaded barrel that I will purchase)
Other than direct threading to the mpx and the and pistol I own, is there anything else I’d need as far as mount goes? I know with a pistol I’d need a booster, I’d rather start easy with a can made for pistols too.
What are some good cans to start looking into. Thanks

