Sig Sauer MCX Patrol 5.56 NATO 16" Semi-Auto Rifle – Short-Stroke Piston, KeyMod, Folding Stock
This first-generation Sig Sauer MCX Patrol delivers the company’s modular, piston-driven design in a full-size 16-inch carbine. A quick-change, cold hammer forged barrel, full ambidextrous controls, and a buffer-tube-less recoil system that permits a side-folding stock set it apart for buyers who value adaptability and compact storage.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Light signs of wear and handling are present but remain strictly cosmetic.
What's Included
- SIG MCX owner's manual
- Magpul PMAG 30-round magazine
- Polymer angled foregrip (installed)
The MCX uses a short-stroke gas piston system that runs independently of a buffer tube, allowing the skeleton stock to fold flat for transport without affecting reliability.
Its 16" cold hammer forged carbon-steel barrel features a nitride treatment for corrosion resistance, a medium contour for balanced handling, and 1/2-28 threading for muzzle devices or suppressors. The 1:7 RH twist stabilizes the full range of 5.56 NATO projectiles.
A free-float KeyMod aluminum handguard keeps weight forward of the receiver low while giving plenty of mounting space for accessories. This model represents the early KeyMod version produced between 2015 and 2017 (serial prefix 63C).
Ambidextrous controls, an ambidextrous dual-latch charging handle, and a two-position collapsible stock make this rifle adaptable for left- or right-hand shooters and varying gear setups. The rifle’s quick-change barrel system, secured by a taper-lock nut, enables future caliber swaps within the MCX family.