SIG Sauer MPX Copperhead

SIG Sauer · Personal Defense Weapon · In Production · 2018

Also known as: MPX Copperhead, SIG Copperhead

Overview

The SIG Sauer MPX Copperhead is an ultra-compact member of the MPX family, built around a 3.5-inch (89 mm) barrel and a monolithic upper receiver with an integrated muzzle brake and an integrated stock knuckle on the lower. Like the parent MPX, it uses a short-stroke gas-piston operating system firing from a closed rotating bolt - a deliberate departure from the simple blowback used by most pistol-caliber compacts - which keeps recoil unusually flat for so short a weapon. The commercial pistol configuration ships with SIG's Pivoting Contour Brace (PCB), a swivelling stabilizing brace that deploys quickly and conforms to the shooter's arm. Chambered in 9x19mm Parabellum and fed by proprietary translucent polymer magazines, the Copperhead is one of the most compact gas-operated 9mm weapons in production and is marketed for close-quarters and vehicle-borne personal defense.

Specifications

Weight (empty)2000 g (70.5 oz)
Overall Length368 mm (14.49")
Barrel Length89 mm (3.50")
Action TypeGas Operated Short Stroke
Firing MechanismHammer Fired
Trigger TypeSingle Stage
Magazine Capacity20 rounds
Magazine TypeDetachable Box
Muzzle Velocity380 m/s (1247 fps)
Muzzle Energy538 J (397 ft·lbf)
Effective Range50 m (55 yd)
Maximum Range150 m (164 yd)
Rate of Fire850 rpm
Barrel RiflingRight Hand
Rifling Twist254 mm (10.00")
Number of Grooves6
Frame MaterialAluminum
Barrel MaterialSteel
Stock MaterialPolymer
FinishCerakote

Calibers

Features

Base model

Sig-Sauer-Mpx

Service history

Operators

Production

Production years: 2018-present

In production as a commercial braced pistol; select-fire SMG offered to military and law enforcement

Origin

Country of origin: United States

Designer: SIG Sauer engineering team

Notes

The select-fire submachine-gun version of the Copperhead, intended for military and law-enforcement personal-defense roles, is among the shortest gas-operated select-fire weapons ever produced. The widely sold commercial model is semi-automatic only and is legally a pistol with a stabilizing brace. The integrated muzzle brake is permanently affixed to the short barrel and is part of the monolithic upper assembly. Rate-of-fire figure applies to the select-fire SMG variant.

Background

At roughly 14.5 inches long, the Copperhead packs the MPX's rifle-style gas system into a frame barely larger than a handgun - SIG essentially proved you could shrink an AR-pattern operating system to fit in a glovebox while still taming 9mm recoil enough to shoot it one-handed.