SIG Sauer MCX Patrol Gen 1 5.56 NATO Semi-Auto Rifle with 16" Cold-Hammer-Forged Nitrided Barrel & Side-Folding Stock
The first-generation SIG Sauer MCX Patrol pairs a short-stroke gas-piston system with a quick-change barrel architecture, giving shooters caliber-conversion flexibility without the need for a buffer tube. Built in 2015–2016, this USA-made variant features a 16-inch nitrided carbon-steel barrel, a skeletonized aluminum side-folding stock, and full ambidextrous controls. Its internal recoil system, KeyMod free-float handguard, and adjustable two-position gas block make it a practical choice for collectors who value early-run MCX features such as the absence of a forward assist and the 63C serial prefix.
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.
Rifling: Excellent – Sharp lands and grooves.
Specific Condition Notes: Minor scratches and small blemishes are present on the exterior surfaces, but they do not affect function or overall appearance.
What’s Included
- SIG Sauer MCX Patrol Gen 1 rifle
- Three 30-round Magpul PMAG 30 Gen M3 polymer magazines
- CAA polymer vertical foregrip (installed)
- Flip-up polymer backup iron sights, front and rear (installed)
The MCX platform was engineered around a proprietary internal recoil spring assembly, eliminating the need for a traditional AR-style buffer tube. This allows the included aluminum stock to fold flat, reducing overall length for transport without compromising function.
Its 16-inch cold-hammer-forged, nitrided barrel is threaded 1/2-28 and capped with a SIG three-prong flash hider. The nitriding treatment hardens the bore surface, enhancing corrosion resistance and extending barrel life.
A 13-inch free-float KeyMod handguard surrounds the barrel, offering ample real estate for accessories while keeping weight centered. The rifle ships with a CAA vertical foregrip already mounted, and built-in top rail space runs continuous from receiver to handguard for optics or lasers.
Fully ambidextrous controls include the safety selector, magazine release, and bolt catch, making the rifle friendly to right- and left-handed shooters alike. The two-position adjustable gas block lets you fine-tune function when running a suppressor or different ammunition.