Skip to content


The pistol variant of this game-changing system features the revolutionary side-folding Pistol Stabilizing Brace.


The First True Mission-Adaptable Weapon System

Engineered from the ground up to be short, light, and silenced, the SIG MCX features an innovative auto-regulating or two position, short-stroke gas piston operating system. And users can change barrels, calibers, stocks, and handguards in the field.

Side-Folding Pistol Stabilizing Brace

This revolutionary brace offers maximum flexibility and improved single-handed shooting performance.

User-Changeable Barrel with 3-Prong Flash Hider

Choose from 16-inch 5.56 NATO, 300BLK and 7.62x39 barrels offering in-field adaptability. Reducing your signature, a 3-prong flash hider comes standard.


Gas Piston
5.56 NATO / 300 Blk


Click Here for the MCX Mandatory Carriage Assembly Replacement Program

Unlike every other firearm on the market, the SIG MCX was built for optimum performance with the 300BLK cartridge and a suppressor. The outcome is a firearm with superior suppression capability and enhanced reliability with both supersonic and subsonic loads A two-position gas block makes the transition from subsonic to supersonic as fast as flipping the lever. Changing between 300BLK and 5.56 NATO is as simple as swapping barrels and magazines in a matter of minutes. Converting to 7.62x39mm simply requires barrel, magazine, as well as an additional bolt change. Each SIG MCX features an aluminum KeyMod handguard, AR-style lower controls and utilizes standard STANAG magazines. A revolutionary recoil system does not require a buffer tube, allowing the side-folding Pistol Stabilizing Brace. A picatinny top rail allows for the mounting of lights or optics. The aluminum forend allows for rail sections to be added where they are needed, permitting the attachment of accessories. The lower receiver offers familiar AR-style controls. Completely ambidextrous controls include the safety, magazine release and charging handle.

Please Enter Your Zipcode

Some states have legal restrictions for the purchase of items so we need to ask for your location.

Get Updates