Best Sig MCX Accessories And Upgrades (2022 Reviews)

| Last Updated:
October 21, 2023

Being one of the best, or probably the best modular rifles in existence. The Sig MCX was designed to offer an utterly customizable and compact yet powerful rifle for the special forces.

While the MCX is an impeccably reliable and ‘complete’ rifle right out of the box. The modular design does find plausible reasons for adding upgrades.

Here we’ll be discussing some very effective and often important upgrades to the Sig MCX to help you customize an effective, comfortable and suitable rifle. 

Comparison of the Best Sig MCX Accessories and Upgrades

IMAGEPRODUCT
  • 2 MOA red dot with 10 illumination settings with 2 night vision settings
  • Motion activated illumination enhances battery life and improves tactical operation
  • Integrated picatinny rail interface and waterproof plus fogproof performance
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  • Ambidextrous charging handle made using 7075-T6 aluminum for durability
  • Dual contoured lever and checkered textured grips for convenience
  • Heightened rear lip aids in mitigating gas blow back with SBR
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  • 300blk upper with 16.8 inch barrel and ejection port door
  • Full length top rail and M-lok compatible handguard for accessories
  • Includes a suppressor can for noise reduction
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Are All Sig MCX Accessories and Upgrades The Same

Absolutely not. Each Sig MCX accessory and upgrade reviewed on our list serve a different purpose. While a charging handle improves the ease of loading the weapon, a good red dot will help with quick target acquisition and low light accuracy. 

The Sig MCX is itself very complete for a generic user. However, it was designed as a modular rifle for a reason. You may want to switch between calibers using a different upper. Or you may need a telescopic stock instead of the OEM folding model. 

Additionally, the Sig Sauer MCX is available in a few different variants(Rattler, Virtus, SBR, Patrol, and different calibers). Where each of them has certain pros and cons to it. Plus, they may need to be upgraded for different applications. 

Sig MCX (Source)

How to Choose Sig MCX Accessories

Application

Make up your mind about all the possible scenarios where you’ll be using your Sig MCX. For example, a survivalist opinion would require a more compact rifle. Whereas a tactical application will need a rifle with good sights and a telescoping stock. Similarly, a competitive shooter will need a very crisp and reliable trigger.

Interchangeability

The Sig MCX is a popular weapon, but it stands nowhere near an AR-15. With that said, there are a few components between these rifles that can be used interchangeably. Additionally, try to vouch for accessories that are compatible with other weapons in your collection as well. For example, a good red dot or variable zoom scope will serve as an overall accessory for most of your weapons. 

Value For Money

Try to go after a product that delivers good value for money. For example, there’s no point spending money on a $1,500 upper if you don’t really need it. But, if you want the MCX to shoot farther and with more power, an interchangeable 300blk upper will be a good bet for you. 

Review of the Best Sig MCX Accessories and Upgrades

Since Sig Sauer designed the MCX for the military, most of its internal components and upgrades are still manufactured and sold solely by them. However, the accessories are not bound by any such norms and can be found with ease.

Although, choosing the best one in a heap of the aftermarket is quite hectic. That’s why we scoured that enormous sea of options and came up with these best Sig MCX accessories and upgrades.

Best Overall:
Sig Sauer Romeo5 Compact 2 MOA Red Sight

Pros

  • Elevated and easy to mount 
  • IPX-7 waterproof(1 meter) and fog-proof design
  • 2 MOA illuminated red dot with unlimited eye relief
  • Lightweight and compact design with 20mm objective
  • 450 hours battery life on the highest setting(out of 10 settings)
  • Motion sensing for automatic on/off action for long battery life

Cons

  • Only 1x magnification. Suitable for close range only

What Recent Buyers Report

This red dot sight has thousands of customer reviews on online marketplaces and almost 99% of them are positive. Users like the durable and clear construction and adjustable illumination. The most appreciated feature of this sight is the motion-sensing auto/off function followed by the decent and appropriate price.

Why it Stands Out to Us

The Sig Sauer Romeo 5 is a parallax-free red dot sight with 10 illumination settings for different light conditions. It features a 50,000+ hours battery life and the motion detection feature is just amazing. The sight delivers quick target acquisition and is extremely durable to withstand the most rugged usage. 

Who Will Use This Most

The sight is great for competitive shooters, tactical operations, CQB, and home defense. The red dot sight installs within seconds and provides a dependable and flawless optic solution for the MCX. The illumination setting will be useful for people with weak eyesight. Plus it improves acquisition both day and night so close-quarter hunters may also like it to some extent. 

Bottom Line

The Romeo 5 is a reliable, feature-packed, and aptly priced red dot sight for a Sig Sauer MCX. It installs within seconds and offers a parallax-free view of the target with unlimited eye relief. Thus eliminating the POI vs POA issue. The scope has a very long battery life and the swing sensor on/off feature is amazing. 

Runner-up:
 Geissele MCX Super Charging Handle

Pros

  • Ambidextrous and oversized charging handle
  • Also suits short barrel and suppressed MCX rifles
  • Type 3 hardcoat anodized finish and textured surface
  • Durable 3D machined 7075 T6 aluminum construction 

Cons

  • Oversized handle may cause snagging

What Recent Buyers Report

Users seem very impressed with this charging handle. The durable design and oversized charging handle are what seems to please the users most. This handle helps eliminate charging problems that arise due to scope mounts or other precarious issues. 

Why it Stands Out to Us

The Geissele charging handle is the epitome of sophistication and performance for such a product. It has been meticulously designed with precise cuts and texture on all angles. The ambidextrous design is very helpful and the textured lever helps with obtaining the perfect grip. 

Who Will Use This Most

The handle has been specifically designed for people who face handling issues with the OEM MCX charging handle. It is oversized and good for people with large palms. The heightened rear lip has been designed to handle the recoil of short barrel and suppressed MCX rifles which makes it even more versatile. 

Bottom Line

The Geissele MCX charging handle is a useful addition to the rifle especially if you face charging issues or need a more reliable charging apparatus. The handle is very durable and ambidextrous. Plus it delivers exceptional grip for the user and will function flawlessly for years to come.

3. Sig Sauer MCX 300BLK Suppressed Complete Upper

Pros

  • Pinned and welded suppressor
  • Does not convert your rifle into an SBR
  • Chambered in the versatile .300 blackout caliber
  • Includes lower adapters and a two-stage trigger group
  • Complete upper with full-length top Picatinny rail and keymod points

Cons

  • Costs close to the rifle itself
  • Doesn’t work with the existing trigger

What Recent Buyers Report

The Sig MCX 300 blk upper is a complete solution for people looking to swap calibers instantly. The upper is very well built and functions flawlessly. The suppressor is properly welded and delivers a considerable reduction in noise. Installation does require disassembly but it’s not difficult. 

Why it Stands Out to Us

This upper receiver is a quick solution if you want to switch calibers. The upper comes with all necessary components and tools to make the switch. Plus the duo-trigger included in the package is way lighter than the OEM trigger. The suppressor also adds to the value of this upper.

Who Will Use This Most

This upper is suitable for people who want to use the .300 blk caliber on their existing 5.56 Sig Sauer MCX while avoiding gunsmith costs. The added suppressor makes it suitable for indoor range use and tactical applications. Plus the .300 blk is a good caliber for hunting and defense.  

Bottom Line

The Sig MCX 300BLK upper is a value for money product offering instant replacement of caliber. The upper comes complete and includes an adapter and a two-stage trigger which enhances accuracy and overall performance. While the upper costs close to an MCX itself. It is a worthwhile investment for tactical operators and competitive shooters. 

4. Sig Sauer MCX Curve Trigger

Pros

  • Works with all Sig MCX models
  • Crisp two-stage trigger for precision
  • Ideal for overall use with the Sig MCX
  • Curved shoe design for optimum control
  • Easy to install with minimal effort and tools
  • Light 4.5 lb total pull weight(2.5 lbs first stage and 2 lbs second stage)

Cons

  • A fair bit expensive

What Recent Buyers Report

The trigger was reported to be exceptional, precise, and easy-to-install with the Sig Sauer MCX. Users like the lightweight pull and crisp break with absolutely zero creep in the second stage. Some users mentioned the high price of this trigger but didn’t seem to mind it over its performance. 

Why it Stands Out to Us

The Geissele trigger is an all-purpose and amazing trigger replacement for the heavy 7 lbs factory trigger. This trigger has a very light and crisp trigger pull with a fast and positive reset for quick follow up shots. The curved trigger helps auto-locate the finger. Plus this complete assembly is easy and quick to swap 

Who Will Use This Most

The trigger is designed for both deliberate aimed fire and snap shooting. This is an all-around trigger suitable for hunting, competitions, tactical, law enforcement, and almost every application for the MCX you can think of. The crisp two-stage trigger improves accuracy and provides consistent follow-up shots. 

Bottom Line

The Sig Sauer MCX has only two aftermarket options for trigger replacement. Sig Sauer and Geissele. This is a ready-to-install trigger with precision machined components having a good resistant finish. This all-purpose trigger is perfect for all applications ranging from plinking to competitions. 

5. Sig Sauer MCX Caliber X-Change Kit

Pros

  • Easy and quick to switch
  • Converts the MCX into a pistol
  • Very good quality and durable construction
  • End of the barrel is tapered for  more surface area
  • Includes required parts, bolt and instruction manual

Cons

  • Requires switching the bolt
  • Will attract legal formalities related to SBR/Pistol

What Recent Buyers Report

Users appreciate the quality, fit, and finish of this caliber exchange kit. The barrel is perfectly machined and coated to prevent damage. The package includes all necessary parts and an extra bolt to eliminate any compatibility issues. The installation is very easy, but switching bolts was a matter frowned upon by some users.

Why it Stands Out to Us

The caliber x-change kit is an instant, easy, and inexpensive solution to switch between the calibers of a Sig MCX. Rather than spending a whole lot of money on a new rifle or receiver. The kit comes with all required parts and necessary instructions for installation. Plus, the durable finish and precise design is also a factor worth considering. 

Who Will Use This Most

The kit is ideal for people who are looking for a viable solution to switch calibers. People who like to switch calibers for hunting, competitions, or any tactical applications will also find this kit quite helpful. The barrel is muzzle threaded and will accept suppressors or brakes to enhance the operation of the rifle. 

Bottom Line

The Sig Sauer MCX caliber exchange kit is an amazing option to switch calibers without the need for buying any extra parts. This kit comes complete with all the parts and a bolt to suit the MCX. However, make sure to check with your local authorities regarding the legal implications associated with this short barrel. 

6. MPX/MCX Folding Telescoping Stock

Pros

  • Compatible with MCX and MPX rifles
  • QD and carabiner sling mounting points
  • Capable for folding as well as telescoping
  • Instant 1913 Picatinny mounting interface
  • Offers compact storage and adjustable LOP in one package

Cons

  • Only one extension point. -0=
  • May be illegal in some states/jurisdictions

What Recent Buyers Report

Buyers report this stock to be of high quality and a flawless and reliable addition to the MCX. The folding and telescoping capability is the most impressive factor for every buyer. The easy to install/remove design and tactical functionality also grabs the attention of users. However, users with a beard reported some hair snagging issues. 

Why it Stands Out to Us

The stock makes the Sig MCX evenly capable of handling almost every situation. The folding and LOP adjustable capability helps with compact storage as well as stance adjustments. The stock doesn’t require the user to perform a full disassembly which is a plus. 

Who Will Use This Most

While the application of this stock is more inclined towards tactical use and compact storage. Every MCX owner interested in getting a unique and universally capable stock should consider buying this. The stock is great for people who want to save on storage space while carrying the weapon. While not compromising with LOP when shooting. 

Bottom Line

The MCX stock is a fair priced upgrade for your rifle which kills two birds with one stone. Where the OEM stock can only fold, this stock can also telescope to offer better cheek weld under different shooting stances. However, the LOP adjustability is quite limited but suitable for the size of an MCX.

Advantages of Investing in Quality Sig MCX Accessories and Upgrades

Let's cover the most grounded reasons for upgrading your MCX:

Improved Performance

The upgrades and accessories reviewed above will improve the overall performance of your Sig Sauer MCX. For example, adding a good red dot sight will enhance your capabilities to quickly acquire a target in both normal and low light conditions. Similarly, adding the folding/telescoping stock will assist with performance, handling, and storage. 

Versatility

As already mentioned, the Sig MCX is a modular weapon. It was designed for the special forces, which eventually means that it has to be a ‘jack of all trades’. Upgrading your MCX with appropriate accessories will make it useful for different situations.

For example, adding the Geissele two-stage trigger will make the rifle prepared for hunting as well as competitions. 

Value For Money

A Sig Sauer MCX rifle costs about twice or thrice more than an average popular AR-15 model. Which means you already make a big investment when buying an MCX.

To make your investment worthwhile, it is imperative that you upgrade and accessorize your rifle to get the most out of it. 

Social Factor

As a Sig Sauer MCX owner, you’ll often find yourself shooting besides AR-15 owners on the range. Many people love boasting about their weapons and making comparisons. So you’d better have your MCX upgraded and accessorized to counter some brash queries. Especially when you’ve already spent upwards of $2,000 on your weapon. 

Conclusion

The Sig Sauer MCX is a modular weapon. Which means it was designed to be customized and complemented with accessories. Adding a few good aftermarket upgrades will improve the overall performance of the weapon while bringing it closer to your personal taste.

Michael Lutes

Michael Lutes is the managing editor and owner at Gun Mann. He is a veteran, gun enthusiast, 3 gun competitor, and 2a advocate. Mike has a passion for innovation and education across the industry to create great content, training, and insights from the best and brightest.

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