SIG Sauer MPX K 9mm Pistol – 4.5" Threaded Barrel, Side-Fold Brace, Ambidextrous Controls
The SIG Sauer MPX K brings the proven MPX lineage into an ultra-compact, brace-equipped package. A 4.5-inch carbon-steel barrel, suppressor-ready threads, and a short-stroke gas-piston system deliver reliable cycling with or without a can. Fully ambidextrous AR-style controls, a crisp 4.5-lb single-stage trigger, and a side-folding Pivoting Contour Brace give this pistol fast handling and true modular flexibility.
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: Displays mild evidence of previous handling but no functional or cosmetic concerns.
What’s Included
- Olight Odin GL-Mini weapon light with remote pressure switch
- Maglula LULA 9 mm loader & unloader for SIG MPX
- Four SIG Sauer proprietary 30-round MPX polymer magazines
The MPX K’s MCX-derived short-stroke piston system keeps fouling out of the action and is tuned for smooth, reliable function when suppressed. A nitride-treated, free-float barrel with an M13.5×1 LH threaded muzzle and three-prong flash hider makes adding a suppressor straightforward.
Controls are truly ambidextrous: mag release, safety selector, charging handle, and bolt catch mirror on both sides for seamless operation by any shooter. The flat-face, single-stage trigger—co-developed with Timney—breaks cleanly at approximately 4.5 lb, helping make fast, accurate follow-up shots second nature.
The 7075-T6 aluminum receiver set wears a durable hard-coat anodized finish and mates to a short free-float M-LOK handguard with a full-length Picatinny top rail for optic and accessory placement. The side-folding Pivoting Contour Brace locks solidly yet can be fired while folded, reducing overall footprint without sacrificing control.
Modularity is at the core of the MPX platform: barrels, handguards, and other components swap easily to adapt caliber, length, or mission. Proprietary dual-feed MPX magazines provide reliable 30-round capacity and lock the bolt open after the last shot.