SIG Sauer MPX K
SIG Sauer · Personal Defense Weapon · In Production · 2015
Also known as: MPX K, MPX-K, MPX Kurz
Overview
The SIG Sauer MPX K is the compact 'Kurz' configuration of the MPX, built around a 4.5-inch cold-hammer-forged barrel with a short M-LOK handguard. It retains the MPX's short-stroke gas-piston operating system firing from a closed rotating bolt, AR-pattern lower-receiver ergonomics, and proprietary translucent polymer magazines (typically 35 rounds). With a 1:10 twist barrel and a free-floated, suppressor-ready muzzle, the MPX K is positioned as a controllable, suppressed-capable close-quarters 9mm carbine/PDW. Commercial versions are semi-automatic-only braced pistols or short-barreled rifles; the select-fire submachine-gun version is offered to military and law-enforcement users.
Specifications
| Weight (empty) | 2268 g (80.0 oz) |
| Overall Length | 565 mm (22.24") |
| Barrel Length | 114 mm (4.49") |
| Height | 203 mm (7.99") |
| Width | 61 mm (2.40") |
| Action Type | Gas Operated Short Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 35 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 390 m/s (1280 fps) |
| Muzzle Energy | 567 J (418 ft·lbf) |
| Effective Range | 100 m (109 yd) |
| Maximum Range | 200 m (219 yd) |
| Rate of Fire | 850 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 6 |
| Frame Material | Aluminum |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Nitride |
Calibers
- 9x19mm Parabellum · primary · 9mm NATO — also known as 9mm Luger, 9mm NATO, 9x19mm
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine, Proprietary Polymer Magazine
- Safety mechanisms: Ambidextrous Manual Safety, Firing Pin Safety, Trigger Safety
- Features: Short Stroke Gas Piston, Closed Bolt Firing, Ambidextrous Controls, M-Lok Handguard, Free Floating Barrel, Handstop, Ar15 Style Controls, Picatinny Rail, Translucent Polymer Magazine, Suppressor Ready
Base model
Service history
Operators
- US Law Enforcement (Various) · as MPX K
Production
Production years: 2015-present
In production in semi-automatic pistol and SBR configurations; select-fire SMG offered to military and law enforcement
Origin
Country of origin: United States
Designer: SIG Sauer engineering team
Notes
The MPX K was frequently positioned by reviewers as a modern competitor to the Heckler & Koch MP5K. Its gas-piston system and internal buffer give it markedly flatter recoil than blowback PDWs of similar size. Magazines are proprietary and not interchangeable with Glock, Colt SMG, or MP5 feed devices. Rate-of-fire figure applies to the select-fire SMG variant; commercial models are semi-automatic only.
Background
Reviewers nicknamed the MPX K the 'MP5 killer' - SIG's bet that a gas-piston 9mm could out-shoot the half-century-old roller-delayed icon at its own compact-PDW game, trading the MP5's legendary smoothness for AR-15 ergonomics and a quick-change barrel.