Sig Sauer M400 Forge 5.56 NATO Rifle – Concrete Gray Cerakote | 16″ CHF Barrel, ROMEO-MSR Gen II, TriggerTech 2-Stage, Magpul SL-K Stock

The Sig Sauer M400 Forge in Concrete Gray is a purpose-built, feature-rich AR-15 platform rifle chambered in 5.56 NATO that delivers exceptional performance straight out of the box. Designed for serious shooters who demand premium components without compromise, the M400 Forge combines a factory TriggerTech trigger, an included red dot optic, and a refined Cerakote finish into one hard-to-find package — now available to order online at VanTon Arms.

Premium Features Built for Performance

At the heart of the M400 Forge is a 16″ cold hammer forged (CHF) steel barrel with a mid-length direct impingement gas system, offering a smoother shooting cycle and improved durability over standard button-rifled barrels. The 1:7 twist rate stabilizes a wide range of 5.56 NATO and .223 Remington projectiles, while the 1/2×28 threaded muzzle with a 90-degree shoulder and included A2 birdcage flash hider keep you suppressor- and muzzle-device-ready.

TriggerTech 2-Stage Flat Blade Trigger

Sig selected the renowned TriggerTech 3.5-pound two-stage flat blade duty trigger for the M400 Forge — a factory upgrade that most AR-15 owners add separately at significant cost. The flat-faced design and frictionless release technology provide a crisp, consistent break that enhances accuracy for both defensive use and precision shooting.

ROMEO-MSR Gen II Red Dot Included

The M400 Forge ships with Sig Sauer’s own ROMEO-MSR Gen II 2 MOA red dot sight already included, offering an immediate, co-witnessed optics solution. The ROMEO-MSR Gen II is a rugged, shake-awake-equipped optic purpose-built for AR-platform rifles — saving you the added cost and hassle of sourcing a compatible optic separately.

Ergonomics & Furniture

• Magpul SL-K 6-Position Adjustable Stock – Low-profile, mil-spec compatible stock with a slim profile and solid lockup in all six positions
• Reduced-Angle Pistol Grip – Promotes a more natural wrist angle for improved trigger control
• Ambidextrous Charging Handle & Manual Safety – Fully ambi controls for left- and right-handed shooters
• Full-Length Free-Floating M-LOK Handguard – Maximizes barrel harmonics by eliminating contact with the barrel, while providing full-length Picatinny top rail and M-LOK attachment points for lights, lasers, grips, and accessories

Concrete Gray Cerakote Finish

The entire rifle — receiver, handguard, and furniture — wears a uniform Concrete Gray Cerakote finish, providing outstanding corrosion resistance, hardness, and a distinctive tactical aesthetic that stands apart from standard black AR builds.

Specifications

• Caliber: 5.56 NATO
• Action: Semi-Automatic, Mid-Length Direct Impingement
• Barrel Length: 16 in (406.4 mm)
• Barrel Material: Cold Hammer Forged Steel
• Twist Rate: 1:7
• Muzzle Threads: 1/2×28, 90° Shouldered
• Muzzle Device: A2 Birdcage Flash Hider
• Overall Length: 35.5 in (901.7 mm) | Collapsed: 32.25 in
• Width: 2.7 in (68.58 mm)
• Height: 9.4 in
• Weight: 6.8 lb
• Trigger: TriggerTech 3.5 lb Two-Stage Flat Blade
• Stock: Magpul SL-K 6-Position
• Handguard: M-LOK, Full-Length Free-Float
• Rail: Full-Length Picatinny Top / M-LOK Sides
• Safety: Ambidextrous
• Magazine: (1) 30-Round AR-15 Polymer Magazine Included
• Optic Included: ROMEO-MSR Gen II 2 MOA Red Dot
• Finish: Concrete Gray Cerakote
• SKU: LIP|SIRM40055616FCN

The Sig Sauer M400 Forge Concrete Gray is a hard-to-find, fully-equipped AR-15 at a competitive price point. Don’t miss your chance to add this premium rifle to your collection — order online today at VanTon Arms and enjoy fast nationwide shipping to your preferred FFL dealer.