SIG Sauer MCX Rattler Canebrake .300 BLK Pistol with Pivoting Contour Brace - Coyote Brown - 5.5"

Manufactured by Sig Sauer
Manufactured by Sig Sauer
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Handguns are regulated by the ATF have restrictions and requirements:
 •Your Entire Order will ship only to a Federal Firearm License holder
•Carriers and shipping methods are limited
•A copy of your order/invoice as well as the current FFL License for your local dealer must be emailed to ffl@primaryarms.



The Sig Sauer MCX Rattler Pistol is built from the ground up to be a compact .300 Blackout weapon system with AR-15 familiarity. The two main driving factors behind the development of this MCX are rapid deployment and personal defense. This model comes with the pivoting contour brace (PCB) that can be folded to the side for extremely compact storage in a backpack and can be fully extended in a matter of seconds when needed. It features a 5.5” barrel with a 1:5 twist rate and chambered in .300 Blackout to pack a punch at short defensive ranges. For reliable function, The MCX Rattler PCB has an adjustable gas piston system for either suppressed or unsuppressed use. The pistol version is the fastest way to get a usable gun in your hands for home defense while still giving you the option to file for a tax stamp and convert it to an SBR in the future.

  • 5.5” carbon steel barrel with 1:5 twist rate
  • Chambered in .300 BLK
  • Suppressor Ready
  • Adjustable gas piston system
  • AR-15 familiarity and mag/pistol grip compatibility
  • M-LOK handguard with QD sling swivel slots
  • PCB side folding pistol brace
  • Sig enhanced trigger with enlarged trigger guard
  • Full length picatinny top rail
  • Coyote Brown

The .300 Blackout Rattler Pistol will feel familiar in any AR-15 enthusiasts’ hands. The safety selector, magazine release, and bolt are roughly in the same positions and it even features the same style of latched rear charging handle. While these parts are proprietary, the pistol grip is compatible with AR-15 styles, so you can use your favorite. It also uses AR-15 style magazines whether it is an Aluminum Mil-Spec or Polymer PMAG. The handguard features M-LOK slots for attaching lights, lasers, or any other accessory you need (vertical foregrips cannot be attached to pistols). It also has quick detach sling swivel slots at the front and rear for carrying or added stability while shooting. The full length picatinny top rail is ready for whatever optics or iron sight combo you want, so you can head to the range and get sighted in.

Sig Sauer is a world-renowned firearms manufacturer with a rich history of innovation and design leadership. No other firearms manufacturer is so highly regarded and so universally respected for the quality, reliability, and safety of its products. Since 1864 they have expanded their product line to include suppressors, optics, ammo, and airguns to provide customers with a greater range of firearms and equipment.
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Barrel Length5.5
BrandSig Sauer
Caliber Gauge300 Blackout
Weight6.5 lbs

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