Sig Proforce MPX AEG Review

picture of vfc sig mpx aeg airsoft gun box
Size and Weight 98%
Power 88%
Durability and Build Quality 94%
Value for Money 92%
✅ Extremely detailed, realistic❌ Not exactly the cheapest airsoft rifle
✅ Durable, full metal construction❌ Proprietary mag
✅ Compact PCC, great for CQB games❌ Front wired – not a ton of battery space
✅ Great ROF on auto
✅ True quick change spring
✅ Easily swappable stock
✅ Very upgradable

Introduced in 2015, the SIG MPX is a 9mm submachine gun designed by SIG Sauer whose compact design, light weight, reliability and performance, has made it popular with police and security forces worldwide.

The MPX’s aggressive looks and maneuverable handling has made it highly desirable in the airsoft world as well, particularly among fans of CQB games. 

Licensed by SIG Sauer and produced by VFC, the SIG Proforce MPX AEG is an official replica of the MPX and has generated a lot of interest since its release. 

To find out if it lives up to the reputation of its real steel inspiration, and to figure out if its worth your time and money, we decided to take a closer look for ourselves. 


ActionSemi, Auto
FPS~ 370 FPS @ 0.20g BBs 
Hop upAdjustable
Inner barrel 6.61 inch (168 mm) 
Total Length25 inches (635 mm)
Weight5.6 lbs (2.54 kg) empty
ConstructionMetal Receivers, plastic grip and butt

How Much Does The Airsoft SIG MPX AEG Resemble A Real Steel MPX?

picture of the vfc sig mpx aeg unboxed from the side
SIG Sauer Proforce MPX AEGSIG Sauer MPX PCC
Weight (empty)5.6 lbs (2.54kg)6.1 lbs  (2.76 KG)
Total Length25.3 in (635 mm)25.7 in (652 mm)
Ambidextrous safetyYesYes
Ambidextrous mag releaseYesYes
Mag typeStickStick 
Caliber 9mm9mm
ConstructionAluminum alloy with polymer grip and buttstockSteel with polymer grip and buttstock
Picatinny rail positionsFull length top, M-LOK with 3, 6 and 9Full length top, M-LOK with 3, 6, and 9 (2nd gen)

On the whole, the SIG Proforce MPX AEG is a realistic and accurately designed replica of a real steel MPX pistol caliber carbine, in our opinion.

In terms of its overall dimensions, VFC’s MPX is a pretty close match for its real steel inspiration, with the airsoft version being only fractionally smaller and lighter (by a few ounces) than the actual firearm. 

In addition to its size and heft, the VFC also replicates the external details and features of a real steel MPX, including its ambidextrous controls and charging handle, all metal frame, telescoping and folding stock, M-LOK handguard, QD sling mounts and more.

picture of external controls on sig mpx aeg showing realistic details

There is even a dual return spring, which is a nice touch and is accurate to the real steel design, although not necessarily the most functional for an airsoft gun. 

All this should perhaps come as no surprise as, being part of SIG Sauer’s Proforce line, the gun is designed to be used for training purposes as well as airsoft gameplay, being intended to replicate the feel and weight of a real steel MPX so that professionals can practice and sharpen their handling skills, manual of arms and muscle memory. 

Like its big brother, the Virtus SBR, the SIG MPX AEG also comes with a rear facing picatinny rail, which acts as an attachment point for the gun’s stock and allows the gun to readily accept any number of stocks, such as visor stocks, fixed stocks and more. 

Finally, being fully licensed by SIG Sauer, the MPX AEG comes with a wide variety of authentic SIG trades and roll marks, which is good news for milsimmers, firearms enthusiasts and airsoft collectors. 

These include high visibility SIG Sauer trademarks across the grips and the company’s highly distinctive logo and model information on the mag well, which admittedly is a bit more subtle and stealthy than the metal badge affixed to its Vitrus counterpart. 

picture of sig sauer logo on mpx aeg showing model name and brand markings

How Does The SIG Sauer MPX Perform As An Airsoft AEG?

picture of sig mpx aeg airsoft gun in box

Build-quality and construction

Intended for both practice and airsoft use, as might be imagined the SIG Sauer MPX is a pretty well-built and solid airsoft gun overall.

The gun is pretty much all-metal, with CNC aluminum alloy receivers, aluminum M-LOK   handguard, alloy buffer tube and even metal switches and controls. 

The only plastic really used on the gun is in its grip and buttstock, which are themselves made of a pretty tough reinforced polymer material.

As a result, although it is pretty compact, the Sig MPX AEG is a pretty durable little airsoft PCC and should stand up to typical handling and gameplay without any issue, in our opinion. 

Perhaps as importantly, the gun is also quite well put together. 

When we handled it, its receivers seemed pretty tightly fitted, the handguard had little to no wobble to it, the controls were all properly fitted and worked smoothly and the frame showed no real sign of bending, rattling or looseness. 

Even the railed telescoping/folding stock seemed pretty solid and slid back and forth smoothly and folded flat without much of an issue, which we always appreciate.

The SIG Proforce MPX AEG comes with a full length metal top rail that should fit just about any optics you might want to attach to it (real steel included, which is nice), as well as an aluminum M-LOK handguard.

close up picture of sig mpx aeg mlok handguard


This rather cool looking and skeletonized handguard gives the gun the ability to pretty freely accept accessories across the 3, 6, and 9 positions and is quite a bit smoother, less prone to snagging and generally easier to grab onto compared to a typical quad rail set up. 

The use of an M-LOK handguard also serves to keep the MPX’s front end pretty light, which makes it a lot easier to swing from target to target, something that can be very helpful in fast-paced CQB games. 

Players should keep in mind, however, that due to its rather compact size (about 4.5 inches), space on the the handguard is a bit more limited compared to typical airsoft carbines and rifles, so it is a bit harder to load it up with tons of tactical accessories without looking ridiculous or affecting its handling.

In addition to its space for accessories, the SIG MPX AEG also comes with a 14mm CCW threaded outer barrel under its flash hider, which means that attaching most suppressors or tracer units to it should be pretty simple. 

Inside, much like its big brother the MCX and other VFC rifles of note, the SIG MPX makes use of the 2nd generation Avalon ECS gearbox. 

This gearbox is found inside a reinforced metal frame and sports sintered steel gears in a higher speed 16:1 ratio, 8mm bearings, a half-steel rack piston with 2nd tooth delete and a ported aluminum piston head, a nozzle with a single O-ring and an integrated MOSFET. 

Happily, the gun does come with a true quick change spring system that allows users to quickly pop springs in and out of the gearbox from the rear of the gun, meaning there’s no need to remove the gearbox from the gun to swap springs.

Consequently, the gun can be up or down-powered in a matter of seconds, which can be helpful if taking the gun to a CQB field with stricter FPS limits. 

All of this is powered by a high-torque neodymium motor, an decent upgrade from the ferrite motors commonly found on most airsoft guns, while essential spin is provided by a pretty standard black VFC rotary-style hop up unit that is pretty capable when it comes to light and midweight (0.30 g, 0.32 g) BBs. 

close up picture of the mpx aeg hop up unit showing rotary action

BBs are then fired out of a 6.6 inch (168mm) long 6.05mm diameter tightbore brass inner barrel that seemed pretty decently smoothed and finished when we took a look at it. 

Finally, towards the rear, the gun’s stock is telescoping and folding and features a nice, thick plastic buttstock that’s pretty comfortable to shoulder.

The stock has the full 5 points of movement, which lets the gun better suit players with different arm lengths. 

This is done via a small trigger-style adjustment button that can feel a bit odd to use at first, especially for those used to more AR-style crane stocks, but does go a long way in preventing accidental collapses when in use.

close up picture of button on mpx aeg stock

 The stock also folds down pretty tightly and securely, which takes the gun down to a highly compact 16.7 inches and makes it very easy to carry in tight areas. 

As we’ve mentioned, the stock is attached to a picatinny rail segment, which means (in addition to accepting a ton of different replacements) it can be detached pretty easily, letting the AEG be freely used in its ultra-compact form should users wish. 

On the downside, the use of this kind of stock set up does mean that the MPX is, by necessity, front wired.

Because of its compact dimensions there isn’t a ton of space in its handguard for batteries, which means that users will be a bit more limited in terms of the types of batteries it can comfortably fit (think small 11.1V stick LiPos). 

Further, because of the skeletonized nature of the M-LOK, fans of outdoor games should be careful that too much debris, dirt and mud doesn’t jam up the battery compartment too badly. 

Performance and accuracy

Much like its real steel counterpart, the SIG Proforce MPX AEG is a capable little performer.

Fitted with an 11.1V LiPo and using 0.20g BBs we saw the gun get around 370-375 FPS, which gives it enough power for nearly any game and should let it easily keep up with most opponents’ carbines. 

This can, of course, make it a little too powerful for some CQB or indoor ranges out of the box.

Happily, the gun’s gearbox does have a quick change spring system that will let users swap in some M100s or M90s to bring its power down to sub 350 FPS without much fuss. 

When it comes to rate of fire, the gun is quite quick, as well. 

With 11.1V batteries, we saw the gun fire around 19-20 RPS on full auto, which should outperform most typical stock airsoft carbines and assault rifles on the field and puts the gun solidly on par with other solid CQB performers, such as the Honey Badger PDW15 and others. 

Trigger response is also quite good with the MCX.

Thanks largely to its high torque motor and higher performance gears, the gun has an even and crisp trigger break and quick reset and generally avoids the heavy, mushier feeling that plagues some of its rivals. 

Finally, when it comes to accuracy, the SIG is, in our opinion, really at home in close to medium range engagements. 

At under 70 feet (21 m) the gun delivers pretty tight groupings for an airsoft gun, and it is capable of reliably hitting torso-sized targets to around 120 feet (36 m) out of the box. 

While perhaps lacking some of the long range precision of longer barreled airsoft carbines and rifles, keep in mind that this is a more CQB-optimized airsoft gun and 120 feet is probably more than enough for most of the games it will be brought to. 


The SIG Proforce MPX AEG is actually pretty comfortable and easy to handle. 

At just over 5.5 lbs, the gun feels very solid in-hand without its weight becoming overwhelming, being just little heavier than the ultra-lightweight G&G SSG-1 and just about the same as the G&G Honey Badger or the ARP9

This heft, combined with the gun’s all metal design, helps the MPX AEG feel a lot more like a real-steel firearm – good news for fans of realism in airsoft, as well as those looking for a solid practice tool.  

Although it’s not extremely lightweight, the SIG Proforce MPX AEG is also not particularly hard to carry for long periods of time thanks to its well-balanced weight distribution. 

With a skeletonized front end and a PPC-style stock, most of the gun’s weight is located at the center, allowing it to sit nicely over a user’s wrist and preventing it from overworking their arm/shoulder muscles as they run and gun. 

The MPX AEG is also very compact and easy to maneuver around with in tight spaces. 

Being able to go from 16.7 inches long (folded) to a maximum of just over 25 inches (stock unfolded, extended), it is ideally built for CQB games and can more easily be swung/fired around walls and obstacles compared to longer rifles and carbines. 

In terms of its grip, the gun comes with a thick SIG-style grip with a gently rounded rear section, making it very ergonomic for most hand sizes.  

This grip is nicely stippled, with front and rear additional texturing, and does provide users with a nice firm hold on the gun in pretty much all weather conditions. 

Finally, like its real steel inspiration, the SIG MPX AEG is pretty ambidextrous, sporting dual side controls, dual mag releases and, of course, a center charging handle and QD stock sling point.

close up picture showing ambidextrous controls on sig mpx aeg airsoft gun

All of this makes the gun equally easy for left and right-handed users to operate.


Although slightly different in looks and design than a typical M4 airsoft gun, takedown of a SIG proforce MPX AEG should be easy to those familiar with the AR-design. 

Users simply pop the front body pins to detach the upper receiver, which then allows the gun to be inspected for damage and cleaned. 

In terms of repairs and upgrades, the gun’s Avalon gearbox is pretty popular and widely used on VFC guns and there are tons of OEM replacements out there on the market. 

Further, being completely V2 compatible, it can easily accept many third party upgrades, such as improved gears, programmable ETU, tighter bore barrel, upgraded hop up and so on. 

Magazine Type and Capacity

The Sig MPX AEG comes with a plastic 9mm stick-sype mid cap magazine that holds about 100 BBs. 

The magazine is translucent and textured, which allows users to get a firm grip on it when conditions get a little wet, and even comes with mock 9mm bullets that add a really cool, realistic touch to the gun.

The mag feeds quite well, although due to the relative strength and size of the mag release spring, it can take a bit of force to get it to seated into the gun.

Unfortunately, the MPX AEG uses proprietary magazines. 

While spares are pretty easy to find and not particularly too expensive, being unable to pick up cheap spares or higher capacity options can be a bit annoying.


Note: All prices current as of writing. All prices in USD. 

Typically sold for around $450, the SIG Proforce MPX AEG isn’t exactly cheap. 

At around the same price as a Krytac Kriss Vector or Scorpion Evo 3, it is certainly on the premium end of the AEG market.

That said, for the price you do get a full metal, officially licensed MPX replica with high build quality, ergonomic handling, a solid, reliable and upgradable gearbox, good ROF and extremely well-balanced and customizable power.


SIG Sauer MPX Airsoft AEG Pros and Cons


Very realistic design

With its metal build, attention to detail, authentic SIG Sauer trades and markings and near 1:1 dimensions, the MPX AEG is a highly realistic airsoft replica of the SIG PCC and avoids feeling too plasticky or like a toy, a common problem with airsoft guns of this size. 

Durable full-metal construction 

The Sig MPX is a pretty durable airsoft gun that should stand up to pretty much anything a typical airsoft game can throw at it, with its receivers made of durable CNC metal, its controls made of metal and its furniture made of a tough polymer material. 

Compact PCC 

At 23.5 inches long with its stock collapsed, the SIG MPX AEG is considerable smaller and maneuverable than most airsoft carbines out there. 

For those who really need something small, its stock can also be popped off quickly, taking the gun down to just under 17 inches in length.

Solid ROF

Fitted with an 11.1V LiPo, the SIG MPX AEG can get around 19-20 RPS, making it pretty rapid fire when set to automatic.

True Quick Change Spring System

Unlike many of its competitors, VFC has fitted their MPX AEG with a quick change spring system that opens through the rear of the gun, meaning users don’t have to get to the gearbox to up or down power it.

Swappable Stock

As the MPX AEG’ stock is attached via picatinny rail, it can be popped off quickly and replaced with any number of other options, from fixed folders to visor stocks.

Easy to upgrade

The SIG Proforce MPX AEG  is powered by VFC’s second-gen Avalon ECS gearbox, which is V2 compatible and very easy to upgrade using a host of readily available third party components. 



Often selling for around $450, the SIG MPX AEG isn’t the most affordable airsoft gun around and can take a decent bite out of an airsoft budget. 

Not a ton of battery space

Being compact and front wired, users are a bit more limited in the kind of batteries that will comfortably fit in the handguard of the MPX. 

Proprietary Magazine

Although it is super cool and works quite well, the 9mm-style stick magazine that the Proforce MPX AEG uses is proprietary and so users can’t simply pick up and use whatever spare high cap or box mag they might have lying around. 

Bottom Line

With its realistic design, solid build quality, ergonomic design and capable performance, if you’re looking to add an MPX to your airsoft collection, this VFC might be the right choice for you.

Will Martin – Will has been into airsoft and paintball for well over 10 years, and has done it all – from upgrading and fixing gearboxes as a tech to building custom airsoft loadouts for his friends to supporting off those friends as a DM.