Sig Sauer MCX Rattler LT SBR .300 AAC Blackout

The Sig Sauer MCX Rattler LT SBR is a compact, modular short-barreled rifle chambered for .300 AAC Blackout. It combines a folding stock, ambidextrous controls, and an M-LOK aluminum handguard to provide a maneuverable platform for short-range and confined-space applications. The package includes one 30‑round polymer magazine and is built on the MCX LT modular architecture.

Key Specifications

• Chambered in .300 AAC Blackout.
• Action type is Semi-Auto.
• Barrel construction is Cold hammer forged.
• Includes one 30‑round polymer magazine as shipped.
• Declared capacity is 30 rounds.
• Weight is listed as 5.8 lbs.
• Handguard style is M-LOK aluminum.
• Controls are fully ambidextrous.
• Muzzle device is a suppressor-ready flash hider.
• Rate of twist is 1-in-5.

The MCX Rattler LT SBR delivers a compact, adaptable platform for shooters who prioritize maneuverability and modularity. Its ambidextrous controls, M-LOK interface, and compatibility with MCX LT components make it straightforward to configure for a range of short-range roles and accessories while maintaining a concise, easy-to-handle footprint.