Sig Sauer MPX K 9mm 4.5" Folding Brace Coyote 35RD

Sig Sauer MPX K 9mm 4.5" Folding Brace Coyote 35RD

The Sig Sauer MPX K is a compact 9mm pistol built around SIG's proven short-stroke gas piston operating system. Combining a 4.5-inch threaded barrel, folding SIG PCB brace, M-LOK handguard, and 35-round magazine, this Coyote-finished MPX K delivers a compact and highly configurable platform.

Unlike traditional direct-blowback pistol-caliber platforms, the MPX uses a closed-bolt, short-stroke gas piston system. The design provides smooth, reliable cycling while the compact 4.5-inch barrel keeps the overall package highly maneuverable.

4.5" Threaded Barrel

The MPX K features a 4.5-inch carbon steel barrel with a 1:10 twist rate. The muzzle is threaded M13.5x1 LH, allowing installation of compatible muzzle devices and suppressor mounting solutions.

Folding SIG PCB Brace

A factory-installed SIG Pivot Contour Brace (PCB) folds to the side to significantly reduce the pistol's overall footprint for storage and transportation. The MPX operating system does not require a traditional AR-style receiver extension behind the receiver.

Timney Flat Trigger

The MPX K comes equipped with a single-stage flat trigger co-developed by SIG Sauer and Timney. The trigger provides a crisp break and fast reset suited to the quick-handling characteristics of the MPX platform.

M-LOK Handguard & Picatinny Rail

A lightweight alloy M-LOK handguard provides mounting space for compatible accessories, while the continuous upper Picatinny rail provides ample room for a red dot or other compatible optic.

Coyote Finish

This MPX K configuration features a distinctive Coyote Tan hard-coat anodized finish, providing a durable exterior while setting it apart from standard black MPX configurations.

Key Features

• Compact MPX K 9mm pistol platform
• 4.5" carbon steel barrel
• M13.5x1 LH threaded muzzle
• 1:10 barrel twist rate
• Closed-bolt short-stroke gas piston operating system
• SIG PCB side-folding brace
• Timney co-developed single-stage flat trigger
• Alloy M-LOK handguard
• Top Picatinny optic rail
• Coyote Tan hard-coat anodized finish
• 35-round magazine capacity
• One 35-round polymer magazine included

Specifications

Why Choose the Sig Sauer MPX K?

The Sig Sauer MPX K combines a compact 4.5-inch barrel with the MPX platform's short-stroke piston operating system, premium flat trigger, folding brace, and modular handguard. Its small footprint and 35-round capacity make it a highly configurable 9mm platform, while the threaded barrel provides additional flexibility for compatible muzzle devices.

FFL Item: This firearm must be transferred in accordance with all applicable federal, state, and local laws.