SIG Sauer MCX Rattler .300 AAC Blackout AR Pistol, 8.5-Inch Barrel, Short-Stroke Piston, Telescoping Brace, M-LOK Handguard
This MCX Rattler is a micro-size .300 AAC Blackout AR pistol built around SIG's short-stroke gas piston system with an adjustable regulator. The upper is factory marked "RATTLER" and pairs an ultra-compact barrel and handguard with a continuous Picatinny top rail. It features the MCX internal recoil system with a dual guide-rod telescoping brace and comes with a blast-diverter muzzle device installed and an additional flash hider included.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are minimal markings from previous handling and use. Please refer to the photos for a detailed look at surfaces and small marks.
What's Included
- 1x 30-round Magpul PMAG polymer magazine
- Blast diverter muzzle device (installed)
- Flash hider (loose, unattached)
- M-LOK angled foregrip/hand stop (installed)
- QD push-button sling swivel not included
The MCX short-stroke gas piston system with an adjustable regulator (clearly marked with +/− icons) drives reliable operation in .300 AAC Blackout. An exposed gas system window and AR-pattern controls, including an ejection-port cover, keep the manual of arms familiar while leveraging the MCX architecture.
The upper is marked "RATTLER" and uses the ultra-compact Rattler-pattern barrel and handguard for a tight, maneuverable package. A continuous Picatinny top rail runs across the receiver and handguard, and the free-float aluminum M-LOK handguard provides modern accessory mounting.
The MCX internal recoil system supports a dual guide-rod telescoping brace made of polymer/rubber. The brace assembly integrates a fixed sling loop between the dual guide rods, and QD sling sockets are located on the lower receiver for flexible carry options. An ambidextrous safety selector is standard.
This pistol has a threaded barrel with a blast-diverter style muzzle device installed. A separate flash hider is included loose. It feeds from STANAG-pattern magazines and ships with one 30-round Magpul PMAG. No iron sights are installed from the factory on this example.