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Semi-Automatic Modular Assault Carbine


Semi-Automatic Modular Assault Carbine


The SIG MCX is a relatively new modular offering from Switzerland and has been adopted by a few notable forces to date.
National Flag Graphic
ORIGIN: Switzerland
YEAR: 2015
MANUFACTURER(S): SIG-Sauer - Switzerland
OPERATORS: Indonesia; Netherlands; Switzerland; United Kingdom; United States

Common measurements, and their respective conversions, are shown when possible. Calibers listed may be model/chambering dependent.
ACTION: Semi-Automatic; Short-Stroke Gas-Operated Piston; Rotating Bolt Mechanism
CALIBER(S): 5.56x45mm NATO; 7.62x39mm; 7.62x51mm NATO; .300 AAC Blackout (model dependent).
LENGTH (OVERALL): 908 millimeters (35.75 inches)
LENGTH (BARREL): 406 millimeters (15.98 inches)
WEIGHT (UNLOADED): 5.84 pounds (2.65 kilograms)
SIGHTS: Iron Front and Rear; Optional Optics.
MUZZLE VELOCITY: 3,000 feet-per-second (914 meters-per-second)
RATE-OF-FIRE: 800 rounds-per-minute
RANGE (EFFECTIVE): 1,650 feet (503 meters; 550 yards)

Series Model Variants
• MCX - Base Series Designation
• MCX Carbine - Base Carbine Model; 16" barrel length; civilian and police market trigger groups available.
• MCX SBR ("Short-Barreled Rifle") - 9" barrel length; variable trigger group options.
• MCX Pistol w/ SBX - Semi-automatic machine pistol form; 9" barrel length.
• MCX LVAW ("Low Visibility Assault Weapon") - Select-fire action with short-barrel assembly and suppression assembly; military and police market model.
• MCX-MR ("Mid Range") - Designated Marksman Rifle (DMR) form chambered for 7.62x51mm NATO; 16" fluted stainless steel barrel assembly; 8.9lb weight; M16-style cocking handle.
• MCX VIRTUS - 5.56mm NATO or 300 Blk chambering; 16" barrel length; semi-automatic action.
• MCX VIRTUS Patrol - 5.56mm NATO or 300 Blk chambering; 16" barrel length; semi-automatic action.
• MCX VIRTUS Pistol - Very compact carbine variant; SBX pistol stabilizing brace.
• MCX VIRTUS SBR - Short-barreled rifle form.


Detailing the development and operational history of the SIG MCX Semi-Automatic Modular Assault Carbine.  Entry last updated on 7/10/2017. Authored by Staff Writer. Content ©
The classic AR-15 series of automatic weapons retains a considerable footprint the world over. Many manufacturers have adopted the rifle series in varying guises but the internal workings of this sound weapon system remain. This is the case with the relatively new SIG-Sauer MCX series automatic weapons, carrying over the traditional short-stroke, gas-operated piston action (with rotating bolt). As with other modern SIG offerings, the MCX is billed as a highly modular weapons system, capable of being reconfigured in a variety of ways to suit customer requirements. The series was introduced in 2015.

This sort of broad tactical value means that the MCX can also be made to chamber several cartridge types based on the configuration. The typical chambering is 5.56x45mm NATO but other forms chamber the 7.62x39mm Soviet as well as the .300 ACC Blackout round (7.62x35mm). All forms fire from a 30-round detachable box (STANAG type) magazine inserted ahead of the trigger group. The action is available in both semi- and selective-fire, again, to suit operator requirements (and also market restrictions).

Outwardly, the MCX takes on the conventional AR-15 style shape. The shoulder stock is hinged to fold over the receiver and is made to telescope while also absorbing a good amount of recoil. Over the top of the receiver is a long-running section of Picatinny rail for installing iron sights or specialized optics and aimers. The forend is heavily perforated for effective air cooling of the barrel. All controls are seated near the trigger area for ease of reach (including an ambidextrous manual safety). The barrel protrudes a short distance ahead of the forend and sports a three-pronged flash hider as standard. The barrel is user-changeable to fit the cartridge in play.

Overall weight of the system is in the 2.6 to 2.7 kilogram range and length, with the stock completely extended, is 35.7 inches. The barrel measures 16" in the standard carbine form.

The MCX SBR is the "short-barreled rifle" model (hence its designation) and this variant uses a 9" barrel. The MCX Pistol w/ SBX is a semi-automatic pistol model with a 9" barrel - essentially a very-compact-carbine. The MCX Low Visibility Assault Weapon (LVAW) is a suppressed model with a short barrel - reserved for purchase by military and police service only.

The MCX-MR was a "mid-range" offering at one point in contention for the United States Army's Compact Semi-Automatic Sniper System program (won by Heckler and Koch). It was chambered for 7.62x51mm NATO. With its 16" barrel, it would have seen service in the Designated Marksman (DM) role.

The newer MCX VIRTUS line includes the "Patrol", "Pistol" and "SBR" forms.

Current (2017) operators of the MCX series includes Singapore (special police), the Netherlands (maritime special forces) and the United Kingdom (police special forces). The Dutch received their MCX rifles in November of 2016.