Video: Going Small With The SIG Sauer MPX Copperhead


Shaved down to minuscule proportions, SIG Sauer’s MPX Copperhead cuts the AR pistol down to size.

How the MPX Copperhead shrinks the AR platform:

  • 3.5-inch barrel
  • 2.4-inch width and 14.5-inch overall length
  • 4.5 pounds in weight
  • Slim Rattler grip
  • Rapid deploy Pivoting Contour Brace

Since the introduction of the AR-15 pistol, the style of firearm has tended consistently in one direction – smaller. While gunmakers have made leaps in this direction in the past, shaving an inch here and an ounce there, their efforts seem to pale with what SIG Sauer cooked up for 2019. Making a sizable jump to the petite, the MPX Copperhead shrinks the AR-15 nearly down to the magnitude of, well, a regular old pistol.

copperhead 2

Where this is most notable is the 9mm’s barrel, which is a minuscule 3.5 inches long, the size found on many traditional pistols’ sub-compact models. In the MPX Copperhead’s case, it’s barely enough tube – even with the aid of a muzzle brake – to extend past its monolithic Elite Series upper receiver. And it’s short enough, most interested parties will mumble a word of thanks SIG had the foresight to incorporate an integral hand stop, especially since the pistol is sans a handguard. Anything less might have flirted with disaster.

SIG has seen the svelte dimensions through to all aspects of the MPX Copperhead, including a slim 2.4-inch width and 14.5-inch overall length. The gas-piston operated pistol is outfitted with SIG’s new Pivoting Contour Brace, an adaptive addition that not only swivels to match a shooter’s body position, but also rapidly deploys in a moment’s notice. If the PCB doesn’t fit the bill for you, SIG has engineered an element of flexibility into the Copperhead with a rear Picatinny rail that makes it compatible with all other MCX and MPX stocks and braces.

More AR Info:

Other notables on the MPX Copperhead include Rattler grip, ambidextrous controls, Rem DLC trigger, upper Picatinny rail for optics, Cerakote Coyote finish and 4.5-pound weight. In line with other MPX models, the Copperhead’s $1,835 MSRP comes in on the pricey side when measured against the rest of the AR pistol market.

MPX Copperhead Specs
Operating System: Gas Piston
Caliber: 9mm Luger
Overall Length: 14.5 inches
Overall Width: 2.4 inches
Height: 8 inches
Barrel Length: 3.5 inches
Weight: 4.5 pounds
Twist Rate: 1:10
Mag Type: MPX

For more information on the MPX Copperhead, please visit:


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