The SIG SAUER MCX RATTLER 5.56 BLK 5.5″ M-LOK is engineered for shooters who demand elite performance in the smallest possible package. Built on the proven MCX platform, the RATTLER delivers unmatched reliability, compact maneuverability, and mission-grade durability, making it one of the most sought-after personal defense and CQB firearms on the market.

Designed for military, law enforcement, and responsible civilian use, the MCX RATTLER combines a 5.5-inch cold-hammer-forged barrel, fully ambidextrous controls, and SIG’s legendary short-stroke gas piston system. This ensures the RATTLER runs clean, cool, and reliably—even during rapid strings of fire or suppressed operation.

Whether you need a compact defensive platform, a backpack/travel firearm, or a premium home-defense setup, the MCX RATTLER is built to perform in the tightest environments.

Key Features

• Caliber: 5.56 NATO

• Barrel Length: 5.5″ cold-hammer-forged

• Operating System: Short-stroke gas piston (clean, reliable, low maintenance)

• Handguard: Lightweight M-LOK for accessories, lights, and grips

• Finish: Black (BLK)

• Stock/Brace Compatibility: Designed for ultra-compact folding stock/brace options

• Controls: Fully ambidextrous (safety, charging handle, mag release)

• Threaded Barrel: Ready for suppressor use

• Built for CQB: Minimal signature, fast handling, and exceptional balance

Why the MCX RATTLER Stands Out

The RATTLER isn’t just another compact rifle—it’s purpose-built for real-world defensive conditions. SIG designed the RATTLER for special operations units needing a true rifle-caliber platform that could be concealed, transported easily, and deployed instantly.

Compact Power

Despite its extremely small footprint, the RATTLER maintains excellent performance with 5.56 NATO ammunition. The 5.5-inch barrel is engineered to maximize velocity and reliability in short-barrel configurations.

Battle-Proven MCX Reliability

The short-stroke piston system greatly reduces carbon buildup and heat transfer, significantly improving reliability over traditional direct-impingement rifles—especially when suppressed.

Total Modularity

The M-LOK handguard lets you attach lights, lasers, grips, and other accessories without adding weight or bulk. Combined with SIG’s modular MCX platform, the RATTLER can be configured for:

• Home defense

• Vehicle defense

• Executive protection

• Backpack carry

• Close-quarters tactical setups

Ambidextrous for Any Shooter

Left- or right-handed, you get full control—essential for defensive shooting under stress.

Perfect for Serious Shooters

The SIG MCX RATTLER 5.56 is ideal for:

• Home defense

• Vehicle carry

• Compact PDW builds

• Tactical professionals

• Shooters wanting a premium CQB rifle-caliber platform

With its unmatched combination of compact size, reliability, and modularity, the RATTLER remains one of the most capable defensive firearms SIG SAUER has ever produced.