SIG Sauer MCX Rattler Canebrake .300 AAC Blackout AR Pistol, 5.5 in Barrel, Coyote Tan, Custom Upgrades
This MCX Rattler Canebrake is a compact, piston-driven .300 AAC Blackout AR pistol set up in the Canebrake configuration with an extended SD-diameter M-LOK handguard and coyote-tan receivers. It features a 5.5-inch threaded barrel with a fast 1:5 twist and includes thoughtful upgrades such as a Radian Raptor-LT ambidextrous charging handle, a right-side extended bolt-release lever, a QD sling socket, and flip-up iron sights. The Rattler platform was noted in SOCOM's 2022 CPDW selection, underscoring its purpose-built design.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are markings from previous handling and signs of moderate prior use. Please refer to the pictures for additional details.
What's Included
- 1x 30-round Magpul PMAG (polymer) with external "300 BLACKOUT" identification band
- Flip-up front and rear iron sights (installed)
- Radian Raptor-LT ambidextrous charging handle (installed)
- Right-side extended bolt-release lever (installed)
- M-LOK QD sling socket with QD swivel (installed)
The Canebrake configuration pairs an extended SD-diameter free-float M-LOK handguard with a 5.5-inch threaded barrel in .300 AAC Blackout (7.62x35mm). The short-stroke gas piston system with a rotating bolt is engineered to run the cartridge efficiently in a very compact package. The fast 1:5 rifling twist is optimized for a wide range of .300 BLK projectiles.
The top of the receiver features a full-length 12 o'clock Picatinny rail, and the handguard provides a short forward Picatinny section; the two are non-continuous. The Canebrake layout includes a factory-style inert training device forward of the handguard, and the platform accepts detachable AR-15 pattern magazines. Capacity is 30+1 with the included PMAG.
Controls and handling are enhanced with an ambidextrous safety selector, a Radian Raptor-LT ambidextrous charging handle, and a right-side extended bolt-release lever. A telescoping two-rod brace with a rear QD sling loop supports compact carry and quick adjustment, while the installed M-LOK QD sling socket with captured swivel provides a secure sling interface.
The receivers are alloy with a coyote-tan finish, matched to black furniture and handguard for a purposeful two-tone look. Markings include "SIG MCX MULTI-CAL" and "SIG SAUER, INC., NEWINGTON, NH USA," with a "RATTLER" model plate on the upper. Country of origin is the USA.
Flip-up front and rear iron sights are installed for immediate use, and the top rail provides straightforward alignment. The MCX Rattler platform's selection in SOCOM's 2022 CPDW program highlights its compact, mission-focused design in this caliber and format.