Sig Sauer MCX PDW SBR
The Sig Sauer MCX is an innovative system built around a battle-proven core: Sig’s gas-operated, auto-regulating, short-stroke piston system. The MCX is an incredibly modular, mission-adaptable rifle that allows the user to change calibers, barrel lengths, and stocks in a matter of seconds without any special tools. Changing from .300 BLK to 5.56 NATO only requires a swap out of the barrel and op rod, while converting to 7.62×39 also requires a swap out of the bolt.
The MCX lower receiver is proprietary and cannot be used with a regular AR15 upper because of its inability to accomodate a buffer tube assembly. This is possible because the MCX uses an innovative recoil assembly with a pair of captive recoil springs directly attached to the bolt carrier and located completely within the upper receiver where the charging handle usually is on the standard AR platform. This causes a little bit more girth in the upper receiver with a slightly raised, relocated charging handle, but is more than balanced out with a skeletonized stock replacing almost the entire back half of the standard AR rifle. The stock is mounted onto a vertical Picatinny located on the rear of the lower receiver and is a left side-folding stock designed not to interfere with any operational controls or the ejection port. The upper is reverse compatible with any Mil-Spec AR15 lower, allowing you to upgrade your existing AR platform to the MCX.
The MCX comes with many additional features designed to adapt to any user and situation. An aluminum KeyMod handguard keeps the forend extremely light while providing the ability to mount accessories as required. A full length top rail extends out to the gas block to provide plenty of sturdy real estate for mounting optics and sight systems. QD mounting points are available on either side of the rear of the lower receiver and at the end of the stock as well. The bolt lock is extended and textured and the charging handle, magazine release, and fire controls are all ambidextrous and enlarged for more positive manipulation.
The Sig MCX is extraordinarily light for an AR, but, despite that, is an impressively durable and reliable system. Its gas regulator allows it to seamlessly fire subsonic and supersonic ammunition without issue. It can be easily accessed by removing the handguard, which is held in place by the front takedown pin and slides off effortlessly. Common wear points on the standard AR platform are made to be replaceable on the MCX. These include a cam path insert, feed ramp insert, replaceable deflector and replaceable charging handle catch point inserts. The MCX is engineered to be the complete package, combining extreme balance and modularity, ease of manipulation and control, and is as durable and reliable as it is accurate.