SIG Sauer MCX-R Regulator 7.62x39 Semi-Automatic Rifle — 16" Cold Hammer Forged Barrel, FDE Gen II NiR Cerakote, Fully Ambidextrous Controls
The MCX-R Regulator is the newest evolution of SIG Sauer’s MCX line, chambered in 7.62x39 and built entirely in Newington, New Hampshire. This example stands out for its 16-inch cold hammer forged, medium-contour barrel, Gen II NiR FDE Cerakote finish that reduces near-infra-red signature, and a shotgun-style fixed stock that is a first for the MCX family. A receiver-integrated ARCA rail, fully ambidextrous controls, and a two-stage match trigger make this rifle both versatile and shooter-focused.
Condition
Overall Condition: Excellent — showing only faint signs of prior use or handling.
Bore Condition: Excellent — clean, mirror finish, no signs of wear.
Bore Rifling: Excellent — sharp lands and grooves.
What’s Included
- Factory SIG Sauer cardboard rifle box
- Factory paperwork (user manual and documentation)
- 1× 10-round steel detachable box magazine stamped “MADE IN USA”
- Magpul SGA stock comb and length-of-pull spacer inserts
This MCX-R Regulator uses SIG’s short-stroke gas piston system, delivering cleaner operation and consistent cycling with a wide range of 7.62x39 loads. The 1:9.5-inch right-hand twist is optimized for modern 123–125 grain projectiles, giving buyers confidence in accuracy and terminal performance.
The rifle’s modular lower accepts any MCX upper, allowing straightforward caliber conversions without tools. A two-stage match trigger and enlarged, ambidextrous charging handle provide a precise and intuitive shooting experience, whether right- or left-handed.
SIG’s Gen II NiR FDE Cerakote finish reduces near-infra-red signature while protecting the 7075-T6 aluminum frame and receiver from harsh environments. The free-float aluminum handguard offers full-length M-LOK slots and a top Picatinny rail, while an integrated ARCA rail underneath the receiver interfaces directly with tripods or saddle scabbards.
The fixed polymer stock includes removable spacers and a textured rubber recoil pad, letting shooters fine-tune length of pull for comfort and control. Ambidextrous selector, magazine release, and bolt catch round out a fully ambidextrous control set built for modern demands.