Best Sig MCX Stocks of 2022 – Complete Review

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The Sig MCX is a formidable-looking weapon purposely designed for special forces. This rifle was developed by Sig Sauer to combine the capabilities of a suppressed, lightweight and hard-hitting weapon into a lightweight package.

While the MCX is already a complete weapon, there’s still a considerable modification that can be made to improve its effectiveness - the Stock.

Here we’ll delve deeper into this topic and review the best Sig MCX stocks on the market. 

Comparison of the Best Sig MCX Stocks

  • Durable M-4 style folding stock with easy to install mechanism
  • Allows installation of standard AR-15 type buttstocks on your MCX/MPX
  • Adjustable length of pull, ambidextrous design and swivel knuckle for convenience
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  • Side folding stock with a thin and lightweight frame
  • Good cheek weld, less rattle and faster to deploy
  • Locks up tight in both positions and fits easily in compact spaces
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  • Factory replacement collapsible stock with minimalist design
  • Attaches to the rifle using a standard 1913 adapter interface
  • Accepts swivel studs for compatibility with slings
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What is the Sig MCX Stock Used For? 


Like any other rifle, the purpose of the Sig MCX stock is to provide stability to the shooter. The item allows the shooter to rest the weapon on his/her shoulder and create a stable platform to control the recoil of the weapon. 

Compact Storage

The Sig MCX may come installed with a folding stock. This allows the user to downsize the rifle for easy storage and handling. This item also helps the user to use the rifle in situations where having a stock may hinder the shooting stance.

MPX/MCX M4 Style Folding Stock

Mounting Sling

This might sound important, but a Sig MCX stock does allow you to mount a sling on the rifle. A sling can be of great help when you have to carry a rifle over long distances or rough terrain. Especially when you go hunting or training. 


A good item can be of phenomenal importance in upgrading the accuracy of the rifle. Products are adjustable for LOP or cheek weld can prove very effective in long-range shooting and while taking evasive maneuvers in a desperate situation.

Review of the Best Sig MCX Stocks

Best Overall:
MPX/MCX M4 Style Folding Stock


  • Detachable magazine holder in the bottom 
  • Swivel knuckle and torque adjustable picatinny adapter
  • Adjustable LOP and folding design for convenient usage
  • Ambidextrous stock with a slim design for minimal weight addition
  • Buffer tube and adapter can be removed to use the adapter on other stocks


  • Restricted for use in some states
  • May feel too technical for some users

What Recent Buyers Report

Users of the M4 style MCX stock seem baffled with the performance of this item. The most impressive feature is the easy installation/removal of this stock on the MCX. This product has a solid construction and the extra magazine holder is a boon for competitive shooters. 

Why it Stands Out to Us

The M4 style item is a complete tactical solution for your Sig MCX. It allows you to adjust the LOP, torque and allows you to fold it to minimize storage space. The item also features a magazine holder that offers a quick change of magazines, especially when using two different types of ammunition.

Who Will Use This Most

This item is ideal for MCX owners who need a tactical product for their rifles. Additionally, people favoring the M4 style AR stocks will also find themselves comfortable when using this. This stock is perfect for tactical uses, training, range use and self-defense both indoors and outdoors.

Bottom Line

The Sig Sauer MCX M4 style stock is the best aftermarket stock for the MCX rifle. It allows the user to make appropriate adjustments and allows mounting other style stocks within an instant. It is a must-have aftermarket stock for people who like to train for SHTF or any other tactical purposes. 

Sig Sauer MCX/MPX Thin Side-Folding Stock


  • Solid and stable feel when mounted on the rifle
  • Great for survival, camping and carrying in a car
  • Comfortable cheek weld and very compact when folded
  • Mounts quickly and easily on the 1913 picatinny interface
  • High-quality construction with a skeletonized frame for less weight


  • Prone to snagging if not handled carefully
  • Limited functions for more versatile usage

What Recent Buyers Report

Users of this lightweight item appreciate the easy installation and quick deployment. The product does not rattle in open or closed positions and also doesn’t touch the rifle when folded. The cheek weld has been found to be very comfortable and the item makes the MCX easy to carry. 

Why it Stands Out to Us

The sleek and lightweight design of this item is very impressive. It serves the basic purpose of stability and sits firmly on the receiver in both positions. The product is very easy to install and becomes compact enough to be carried conveniently. Additionally, the item also matches the color and finish of the MCX.

Who Will Use This Most

The item is great for people who mostly carry their Sig MCX in a backpack during camping or hunting trips. The product allows the user to shed a lot of weight from the rifle which in turn helps reduce fatigue. Additionally, people who like minimalistic accessories will definitely like this item.

Bottom Line

The Sig Sauer MCX thin side folding product is a sturdy and stable stock for the rifle in both open and closed positions. The item is easy to install and offers a lightweight and compact solution to the user without compromising with accuracy. 

Best Sig MCX Telescoping Stock:
MPX/MCX Collapsible Stock 1913 Interface


  • Ideal for turning the MCX into an SBR
  • Includes loop and QD point for adding sling
  • Easy to install and offers three different LOP
  • Factory replacement collapsible product manufactured by Sig Sauer


  • Priced high compared to other items on the list
  • Requires you to get a tax stamp(for converting to an SBR)

What Recent Buyers Report

Almost every user of this collapsible product is pleased with it. The item is exceptionally easy to install and looks super-cool on the MCX. Other appreciated factors were the fit, finish, durability, low weight and compact design of the stock to favor storage and handling. 

Why it Stands Out to Us

The product offers three length-of-pull adjustments and is extremely easy to install. The item has an attractive look while keeping its design very simple. The adjustable mechanism of the stock runs very smoothly and the buttpad is quite comfortable to use. The quality of the stock is impeccable, and being an OEM part it fits perfectly well with the MCX. 

Who Will Use This Most

This is the item you need if you are planning to convert your MCX into an SBR. Additionally, the LOP adjustability of the product makes it perfect for tactical uses like CQB and self/home defense. Plus the stock makes the gun look very cool, which is great for people interested in the ‘bragging-game’.

Bottom Line

This Sig collapsible stock is the best choice to convert your MCX into a tactical SBR. The product operates smoothly and allows the shooter to adjust their stance regardless of the situation. This item is very easy to install and will definitely add to the aesthetics of your rifle. 

4. Sig Sauer MCX/MPX/1913HING Folding Brace


  • Nylon strap enables use as a pistol brace
  • ATF compliant design comes ready to install 
  • Can be used with rifle and pistol configuration
  • Fits other rifles with mil-std 1913 picatinny adapter
  • Left folding stock with ultra-strong smooth hinge mechanism


  • A bit overpriced for its design
  • Limited function and the design may feel flimsy

What Recent Buyers Report

While most users appreciate the lightweight and muti-rifle compatibility of this brace. Others complain about the polymer and rubber components in it. Which doesn’t justify the price. However, users seem satisfied with the positive lockup, flat-folding profile 

Why it Stands Out to Us

This brace works both as an item and a brace due to the extra nylon strap. This can come in handy when using different configurations of rifles. Additionally, the brace is very compact and gives the option to lock when folded. Plus it also works with other firearms with compatible adapters. 

Who Will Use This Most

The brace is useful for people who have to tackle legal issues in their state. Plus the brace is also a viable option for people who own both rifle and pistol versions of the MCX. The compact and slim profile of the brace also helps with carrying the rifle on hunting trips. 

Bottom Line

The SB Tactical stabilizing brace provides a lightweight and stable platform for your rifle or pistol configuration MCX. The brace is easy to attach/detach and locks into place when folded or extended. However, the price does seem unjustified. It is still an amazing stock for your MCX. 

Best Sig MCX Folding Stock:
MPX/MCX Folding Telescoping Stock


  • Delivers amazing value for money
  • Offers a good cheek rest for using optics
  • This product folds as well as extend/collapses
  • Well made item attaches easily to the 1913 adapter


  • Takes some time to break-in perfectly
  • The button to adjust LOP has an uncommon design

What Recent Buyers Report

Users appreciate the ingenious design of this item, along with the ease of installation and deployment. The product features high-quality design and offers a comfortable cheek weld. However, some users reported that the folding mechanism takes some time to break-in. 

Why it Stands Out to Us

The product folds and telescopes, which is it’s most important feature. This allows the user to get the benefits of a regular tactical rifle stock and a folding stock in one package. The item installs easily and has a very solid lockup. Plus the release safety button prevents accidental releases. 

Who Will Use This Most

This item is perfect for SBR owners in general. However, it is a desirable item for every MCX owner. Since the stock can both fold and telescope. The product is good for hunting, self-defense, tactical uses, and target practice. The telescopic ability allows the shooter to adjust the LOP which can be crucial in tactical situations. 

Bottom Line

This item from Sig Sauer offers amazing value for money. It delivers folding and telescopic capabilities in a single package and stays secured in place in both positions. Perhaps the item is ideal for every application with an MCX. It sits a cut above others for tactical applications. 

Cautious Considerations to Keep in Mind 

Adding an aftermarket stock to your MCX will enhance its function. However, you must consider certain factors before adding new stock.

Durability and Finish

Make sure that the item you are buying is durable and can withstand pressure. Most MCX stocks(including the ones in our list) have a metal base covered by a polymer casing and rubber buttpads. The finish of the stock must be rugged and resistant to damage. 

Installation and Performance (Stability)

The product must be easy to install and remove when needed. Plus it should be stable and not wiggle in any position. Since this can impede accuracy and handling. Additionally, folding stocks should maintain some gap with the rifle when folded. 

Intended Application and Price

Make sure to evaluate your intended application of the MCX before changing the item. If your purpose is just to make carrying easier, use a folding stock.

If you need more tactical capabilities, use a telescopic stock. If you need to reduce the overall weight, use a skeleton stock. Additionally, consider your budget. 

Sig Sauer MCX/MPX Thin Side-Folding Stock

Legal Implications

Using a folding or telescopic stock may convert your rifle into an SBR. So it’s better to confirm with your local state laws and get the appropriate paperwork done before buying one. 

How to Install a Sig MCX Stock

Replacing the stock on a Sig MCX is pretty easy. Let’s outline it as a step by step procedure for easy comprehension:

Tools you’ll need: 5/64 Allen Key, Torx 27 Screwdriver

  1. Remove the magazine and make sure the weapon is clear.

  2. Loosen the screw on the existing stock using a Torx wrench. 

  3. Remove the buffer inside the rear end of the receiver by removing the set screw using an Allen key.

  4. Take the stock’s locking block and place it in the speck of the spot. Make sure the speck fits flush and tighten it with the Allen key. Now slide the stock onto the back of the picatinny rail behind the receiver. Use the Allen key to tighten the speck screw. 

  5. Add the buffer back and tighten it using the Allen key.

  6. Reinstall the upper receiver and set the takedown pins back into place.

Please note that some stocks won’t require you to disassemble the receiver for replacement. For more tips and detailed insights into the installation process, refer to this video below. 


The Sig MCX is an effective tactical weapon designed for special forces. The standard stock that comes installed with the MCX can be replaced with a different version depending upon the intended applications of the user. Checking the quality, fit, finish and stability of a stock is a good practice before buying one. Additionally, you must also keep an eye out for finish, performance, price and legal implications associated with a product. 

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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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