U.S. Special Forces to purchase Sig Sauer MCX rifle carbine.

The US Special Forces is planning to buy a few number of Sig Sauer MCX rifle, a conversion kit for the M4A1 carbine. The U.S. Army, which is managing the contract on behalf of Special Operations Command (SOCOM), announced the plan on FedBizOpps, the U.S. government’s central contracting website, on Feb. 1, 2018.

SIG Sauer MCX Virtus Patrol 5.56 NATO and 300 BLK carbine (Picture source Sig Sauer)

On February 1, 2018 it was announced that, the U.S. Army Contracting Command-New Jersey, on behalf of PM Soldier Weapons, intends to solicit, negotiate, and award a sole source contract to Sig Sauer pursuant to the authority of 41 U.S.C. 1901 as implemented by FAR Subpart 13.106-1(b). This contemplated sole source contract is for is for the purchase and delivery of the commercially available Sig Sauer MCX Personal Defense Weapons (PDW) Kits to satisfy the Government's requirement for Special Operation Command (SOCOM).

The acquisition of production items from sources other than Sig Sauer will not meet schedule requirements. Sig Sauer was the only company identified through market research that could provide the necessary MCX PDW Parts and Kits which met the Government's requirements for a Commercial off the Shelf (COTS) conversion kit for the M4A1 to create a PDW that meets the specifications identified in the sources sought notice posted to Federal Business Opportunities (FBO).

The SIG MCX is a weapon series designed and manufactured by SIG Sauer that looks like a standard AR-15, but featuring a short-stroke gas piston system, carried over from the SIG MPX submachine gun. It is made in both semi-automatic and selective fire configurations. It is available in rifle, short-barreled rifle, and pistol configurations.

SIG Sauer MCX Virtus Patrol FDE, 16" variation of the revolutionary MCX carbine (Picture source Sig Sauer)

The SIG MCX series features a short-stroke gas piston system to reduce recoil and improve the reliability of the weapon; this was based on the design of the earlier SIG MPX. The MCX features a system that 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 and .300 AAC Blackout, and specially designed STANAG-compatible magazines for 7.62×39mm. The MCX is designed to deliver optimal performance with .300 AAC Blackout and an optional suppressor.

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-center on installation. The barrel can be changed in a matter of seconds to another length or a different caliber. Additionally the barrels are nitride coated for corrosion resistance. It features hardened steel wear points.

All MCX variants have a forend made of aluminum with a KeyMod system to add accessories. Controls are mostly ambidextrous including the charging handle but not the bolt release. Four types of stocks are available for the MCX carbine.

SIG designed the upper receiver to be compatible with standard AR-15 and M16 lower receivers with the help of an adapter.The overall layout of the two rifles is similar.