Sig Sauer MPX-9 Gen 2

[Buckaroobonsai]

Picked it up yesterday and took it out today. Ran some 300 rounds through it. Here’s my two cents.

Design:

Overall great design. Looks like it means business. Love the way the handguard and barrel easily swap out. Same with the stock. I’m new to keymod and totally dig it. Magazines. Translucent so you can see if there’s any ammo left I’m guessing but not so useful for the last handful of rounds which disappear into the magazine well anyways. Otherwise they look kinda funky. Hopefully Magpul gets onboard with that and other parts soon. The flared mag well kicks ass though. Pistol grip. Feels too big for the gun and sits at a weird angle. The standard folding pistol brace gets the job done but looks fugly.

Function:

Capable of nice tight groups at 25 yards. Torso sized targets at 100 yards is do able as well. Charging handle is Ambi but you really need to pull both sides at the same time for smoother operation. LRBHO. Awesome. Works well and a nice tactical advantage over the MP5. Trigger. A little gritty, typical heavy milspec pull but reset is nice and short. Feels like I’ve been doing trigger finger push ups after that many rounds and I could notice it affecting my accuracy as the day went on.

Reliability:

Ran Ranger duty ammo and white box Winchester flawlessly. Don’t know if was because it was getting dirty, but I had a couple double feed failures using LAX Ammo reloads. Maybe a combination of two...

Serviceability:

Easy to break down and clean. The bolt is like a mini AR BCG with (2) guide springs. Mostly proprietary parts of course, but everything looks user friendly for replacement.

Upgrades:

Ordered the Sig collapsible pistol brace to replace the folding one. Looks and functions like the SBR stock but with a brace at the end. Better functionality and hella better looking. Might stamp it later in life and throw a regular collapsible stock on it. A can is tempting too. The factory trigger had to go. Installed a Geissele G2 in less than (5) minutes. Same with the pistol grip, Magpul MOE to the rescue and it feels so much better now. Heard you could swap charging handles but that’s not the case. The stock one is shorter and slightly different at the end. No Gunfighter love for now. Topped it off with an EoTech XPS2 for quicker target acquisition.

Conclusion:

I wanted something that used the same ammo as my Glock 17. Due to the price I looked into an AR-9 first, especially one that could use Glock mags. Ultimately I went with the MPX for the reliability with different types of ammo and it’s purpose specific design. It’s pricey yes, especially with the upgrades, but you know what they say, “cry once”.




The collapsible Sig pistol brace:

[To Bear Arms]

I have swapped out the same parts you did. I am running a Franklin trigger for now and love it. I also did not like the charging handle and just swapped it out for a Radian Raptor charging handle. The Radian takes care of the slop that the factory handle has.

[drew890]

I’ve enjoyed mine.
It now wears an Aimpoint T2 as well.

[Buckaroobonsai]

Nice! You guys have any issues running aftermarket triggers in them? I’ve heard they may be prone to getting damaged? Any other manufacturers making accessory parts for them? Where’d you get the MP5 style sights drew?

[drew890]

My aftermarket trigger only has about 1,000 rounds through it, but it is not showing any signs of abnormal wear.
The HK sights are a Centurian set that I had on another less used upper.

[Buckaroobonsai]

Did you need to re-install the wierd “bridge” part that was attached to the factory trigger?

[drew890]

Did you need to re-install the wierd “bridge” part that was attached to the factory trigger?

I did not bother to.

[Delfuego]

Who is this member "Buckaroobonsai"? He seems very familiar...

[Buckaroobonsai]

Who is this member "Buckaroobonsai"? He seems very familiar...

Never heard of the bum...

[Buckaroobonsai]

Added the Sig (3) position brace and a Magpul Rail Light with Streamlight PolyTac.