The SIG MCX is engineered for .300 BLK and built from the ground up to be silenced, light, and short. The MCX is an innovative weapon system built around a battle-proven core: SIG's gas-operated, short-stroke piston system. Even while in the field, you can configure the SIG MCX as needs or conditions change. The combination of the 13" monolithic upper receiver and handguard create a 17-3/4" continuous top rail. The MCX can also be converted to 5.56 NATO or 7.62x39mm with just a few component changes. The upper is backwards compatible with any mil-spec AR lower, allowing you to upgrade your existing AR platform to the SIG MCX.
The continuous-to-rail upper receiver on the MCX features an integral M1913 rail at 12 o'clock and a free-float barrel system. Additional features include: a beveled and flared magwell, a metal cam path wear insert, a KeyMod aluminum alloy handguard, and multiple integral QD sling points. The controls are ambidextrous for added adaptability. The SIG MCX Carbine has a folding stock for easy transport. 1 in 7" twist.