SIG MCX

The SIG MCX is a family of firearms designed and manufactured by SIG Sauer. It features a short-stroke gas piston system which is inherited from the earlier SIG MPX submachine gun, and is available in rifle, carbine, short-barreled rifle, and pistol configurations (the latter configuration generally conforming to the definition of a compact carbine but for taking a pistol brace rather than a buttstock). The SIG MCX was first introduced at SHOT Show 2015. The rifle was originally designed by SIG USA, the subsidiary of SIG Sauer based in New Hampshire. Designed to be modular and reconfigurable to the individual user's needs, the MCX allows for conversion between 5.56×45mm NATO, .300 AAC Blackout, and 7.62×39mm ammunition, using standard 5.56 mm STANAG magazines for 5.56×45mm NATO/.300 Blackout and specially designed STANAG-compatible magazines for 7.62×39mm. The barrel's profile is tapered at the crown to allow the installation of muzzle devices and direct-thread sound suppressors without the use of washers that degrade performance and allows the devices to self-centered on installation. The barrel can be changed in a matter of seconds to another length or a different caliber.