SIG Sauer MPX K 9mm Pistol | 4.5" Threaded Barrel, Timney 4.5 lb Trigger, Ambidextrous Controls
The MPX K is SIG Sauer’s compact, piston-driven 9mm pistol that blends subgun controllability with familiar AR ergonomics. A short-stroke gas piston and closed rotating bolt keep the action clean and reliable while suppressor-ready features and fully ambidextrous controls make this second-generation MPX exceptionally versatile.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Good – Clean, well-maintained, minor wear marks.
Bore Rifling: Good Rifling – Intact, well-defined lands and grooves.
Specific Condition Notes: The exterior shows a few faint scratches and small cosmetic blemishes; the bore is bright and free of fouling.
What’s Included
- SIG Sauer factory 30-round translucent polymer magazine
- SIG Sauer MPX owner’s manual
The MPX K uses SIG’s proven short-stroke gas piston system, delivering cleaner operation than direct-blowback 9mm designs and maintaining rock-solid lock-up thanks to its closed rotating bolt.
A 4.5" cold-hammer-forged carbon-steel barrel is nitrided for durability and threaded M13.5x1 LH. The factory three-prong flash hider doubles as a suppressor alignment shoulder, while the free-float aluminum M-LOK handguard is trimmed to clear over-barrel suppressors.
Controls are fully ambidextrous, including the mag release, bolt catch, safety selector, and AR-style charging handle, giving both right- and left-handed shooters seamless operation.
The single-stage Timney co-designed trigger breaks at approximately 4.5 lb, offering a crisp, repeatable pull that aids rapid, accurate strings of fire.
A quick-change barrel system and 1913 Picatinny rear end-plate let owners easily configure the pistol with folding braces or stocks (where permitted), making the MPX K adaptable to a wide range of roles.