The Sig Sauer M400 Forge With Romeo-MSR Gen II Red Dot is a refined 16" 5.56 NATO AR-15 built for dependable performance and clean handling. Its cold hammer forged, threaded barrel is paired with a mid-length direct impingement gas system for smooth recoil and consistent accuracy. A 15" free-floating M-LOK handguard, TriggerTech 3.5-pound two-stage flat blade trigger, and Moss Green Cerakote finish create a modern rifle that feels precise and responsive right out of the box.

This M400 Forge configuration arrives ready for the range with a factory-mounted Romeo-MSR Gen II 2 MOA red dot, a 30-round magazine, and a 6-position Magpul SL-K stock for an adjustable fit. The ambidextrous safety and charging handle support comfortable operation for a wide range of shooters, making it well suited for training, home defense, and general range use. Sig Sauer’s attention to detail, from the forged alloy receivers to the tuned trigger, reflects the brand’s reputation for reliable, thoughtfully engineered rifles.

Key Features:

• Manufacturer: Sig Sauer
• Model: M400 Forge With Romeo-MSR Gen II
• Caliber: 5.56 NATO
• Action: Semi-Auto
• Barrel Length: 16" Cold Hammer Forged, Threaded 1/2x28
• Gas System: Mid-Length Direct Impingement
• Capacity: 30 Rounds
• Optic: Romeo-MSR Gen II 2 MOA Red Dot
• Handguard: 15" Free-Floating M-LOK
• Stock: Magpul SL-K 6-Position Adjustable
• Trigger: TriggerTech 3.5-Pound Two-Stage Flat Blade
• Overall Length: 32.25"–35.5"
• Weight: 6.8 Lb