Sig Sauer M400 SDI 5.56 NATO

The Sig Sauer M400 SDI is a semi-automatic modern sporting rifle built to deliver consistent performance for range use, training, and general-purpose shooting. Its design emphasizes ergonomic controls and a mid-length gas system for balanced recoil and reliable operation. The Moss Green Cerakote finish and M-LOK handguard provide a durable, user-friendly platform.

Constructed on an AR-style alloy receiver, the M400 SDI uses an optics-ready upper and a free-floating M-LOK handguard to support accessory mounting while maintaining a slim profile. Controls are fully ambidextrous and the rifle ships with a 6-position Magpul MOE-SL stock and a reduced-angle pistol grip for comfortable ergonomics. The threaded muzzle and included flash hider-compensator accommodate common muzzle accessories and tuning preferences.

Key Specifications

• The caliber is .223 REM/5.56 NATO.
• The barrel length is 16 inches.
• The twist rate is 1:7.
• The thread pattern is 1/2x28.
• The muzzle device is SIG Flash Hider-Compensator.
• The action type is Semi-Auto.
• The operating system is Mid-length direct impingement.
• The stock type is 6-position Magpul MOE-SL (black).
• The magazine included is one 30-round polymer magazine.
• The finish is Moss Green Cerakote.

For shooters seeking a capable AR-platform option, the Sig Sauer M400 SDI offers straightforward features and a durable finish that support range and training applications. Buy the Sig Sauer M400 SDI 5.56 NATO online today for a dependable, well-equipped modern sporting rifle option.