Sig Sauer PMPX3BCH MPX Copperhead 9mm Luger Caliber with 3.50" Barrel, 20+1 Capacity, Coyote Elite Cerakote Metal Finish, Folding Pivoting Contour Brace Stock & Black Polymer Grip Ambidextrous Hand

The Sig Sauer MPX Copperhead 9mm is a compact, modern tactical pistol built on proven submachine gun architecture—ideal for shooters who want rifle-like controls and ergonomics in a short-barreled platform. With its 3.5" barrel, integrated muzzle brake, and 20+1 capacity, the Copperhead delivers the handling familiarity of an AR platform in a genuinely portable package. It's equally at home on the range, in training scenarios, or as a specialized duty pistol for those who value ambidextrous controls and genuine reliability over trends.

The Copperhead's standout feature is its new SIG Pivoting Contour Brace (PCB), which uses a patented swivel mechanism to naturally conform to your arm during firing and deploy rapidly when repositioned. Unlike rigid braces, the PCB actually adapts to shooter movement, reducing fatigue during extended sessions and improving consistency. The monolithic upper receiver sports SIG's Elite Series Coyote Cerakote finish—durable, corrosion-resistant, and optimized for both looks and function.

Operating via short-stroke gas piston, the MPX cycles all standard 9mm ammunition without adjustment, so you're not tied to a single load or brand. The fully-rotating bolt locks completely in battery, delivering the kind of reliability SIG built its reputation on. Every control is truly ambidextrous: dual-sided safety, magazine release, charging handle, and bolt release. Lefties get the same natural, fast manipulation as righties—no compromise.

At 4.5 pounds and 14.5 inches overall with the brace folded, the Copperhead is genuinely compact without feeling like a toy. The carbon-steel barrel, alloy forend, and polymer grip keep weight reasonable while maintaining durability. M1913 Picatinny rail on the upper makes optics mounting straightforward. One 20-round polymer magazine comes in the box.

Key Features

• Short-stroke gas piston system runs all 9mm loads without adjustment
• Fully-rotating locked bolt for enhanced reliability and safety
• SIG Pivoting Contour Brace adapts naturally to arm movement with rapid deployment
• Completely ambidextrous controls: safety, mag release, charging handle, bolt release
• Monolithic upper receiver with integrated stock knuckle lower
• 3.5" carbon-steel barrel with integrated muzzle brake
• Elite Series Coyote Cerakote finish resists corrosion
• Polished, hard-coat single-stage trigger
• M1913 Picatinny rail for optics and accessories
• Genuine AR-platform ergonomics and controls in a compact frame

Specifications

Frequently Asked Questions

Is the MPX Copperhead truly ambidextrous?

Yes. The safety, magazine release, charging handle, and bolt release are all dual-sided, making it equally suitable for left- and right-handed shooters without modifications or workarounds.

What ammunition does the MPX Copperhead run?

The short-stroke gas piston system cycles all standard 9mm Luger ammunition—different weights and brands—without requiring gas valve adjustments or tuning.

How does the Pivoting Contour Brace work?

The PCB uses a patented swivel mechanism that allows the brace to move naturally with your arm during firing, adapting to your personal grip and stance. It can be rapidly repositioned or deployed as needed, unlike fixed braces.

What optics rail does the Copperhead have?

The monolithic upper receiver features an M1913 Picatinny rail for mounting red dots, magnified optics, or other accessories.

What comes in the box?

One 20-round MPX polymer magazine is included with the pistol.