SIG SAUER M400 Forge 5.56 NATO 10 Round Rifle – 16 Inch, Black

Description

SIG SAUER M400-FORGE 5.56 NATO Rifle with ROMEO-MSR Gen II

The SIG SAUER M400-FORGE combines a duty-oriented direct-impingement operating system with a factory-installed optic and a carefully selected control package. This black 10-round configuration, manufacturer part number RM400-556N-16B-FORGE-10, is chambered in 5.56 NATO and built around a 16-inch cold-hammer-forged steel barrel. It ships with a ROMEO-MSR Gen II red-dot sight and one 10-round polymer magazine, making it a complete, ready-to-configure modern sporting rifle for range use, training, and general-purpose applications.

Cold-Hammer-Forged Barrel and Mid-Length Gas System

The 16-inch barrel uses cold-hammer-forged steel construction for a durable foundation and has a 1:7-inch twist rate suited to a broad selection of common 5.56 NATO and .223 Remington projectile weights. Its muzzle is threaded 1/2×28 with a 90-degree shoulder and fitted with an A2 birdcage flash hider. SIG SAUER pairs the barrel with a mid-length direct-impingement system, a configuration chosen to provide familiar AR-pattern operation with a practical balance of reliability, recoil impulse, and component service life.

A free-floating black anodized alloy handguard surrounds the barrel. M-LOK attachment slots provide flexible placement for compatible lights, sling hardware, hand stops, and other accessories without adding unnecessary bulk. A full-length Picatinny top rail maintains continuous mounting space along the upper receiver and handguard for the included optic or other compatible aiming and observation equipment.

Factory-Installed ROMEO-MSR Gen II

This model includes SIG SAUER’s ROMEO-MSR Gen II with a 2 MOA red dot. The compact, unmagnified sight supports fast target acquisition and an unrestricted, both-eyes-open shooting position. Installing the optic at the factory gives the rifle a useful sighting solution out of the box while preserving the option to rearrange the top rail or install a different compatible optic later. As with any firearm-mounted sight, the user should confirm mounting security and establish a proper zero before relying on the rifle.

Trigger and Ambidextrous Controls

A TriggerTech 3.5-pound two-stage flat-blade trigger is a defining feature of the M400-FORGE package. The two-stage design gives the shooter a distinct initial take-up followed by a defined break, supporting deliberate trigger control from common field and bench positions. The flat trigger face offers a consistent contact surface across a range of finger placements.

SIG SAUER equips the rifle with an ambidextrous safety and ambidextrous charging handle. These controls make administrative handling and manipulation more accessible from either shoulder, whether the shooter is left-handed or practicing positional transitions. The familiar AR-15 layout also makes the platform approachable for users already trained on standard AR-pattern rifles.

Adjustable Furniture and Practical Handling

The six-position Magpul SL-K stock lets the user tune length of pull for body size, clothing, armor, or shooting position. A reduced-angle black grip supports a more natural wrist position, particularly when the stock is run at shorter settings. The rifle measures approximately 35.5 inches with the stock extended and 32.25 inches collapsed, with a listed weight of about 6.8 pounds before accessories and ammunition. Those dimensions keep the system maneuverable without giving up a full-length 16-inch barrel.

Key Features

• 5.56 NATO semi-automatic AR-pattern rifle
• 16-inch cold-hammer-forged steel barrel
• 1:7-inch twist rate and 1/2×28 muzzle threads
• A2 birdcage flash hider
• Mid-length direct-impingement operating system
• ROMEO-MSR Gen II optic with 2 MOA red dot
• TriggerTech 3.5-pound two-stage flat trigger
• Ambidextrous safety and charging handle
• Free-floating black anodized M-LOK handguard
• Full-length Picatinny top rail
• Six-position Magpul SL-K stock and reduced-angle grip
• One 10-round polymer magazine included

Exact Configuration

This listing is for the black anodized, 10-round M400-FORGE identified by UPC 798681744121. It is distinct from 30-round, fixed-stock, and alternate-color M400-FORGE variants. Firearm transfer, magazine-capacity, and feature restrictions vary by jurisdiction; confirm that this exact configuration is legal where you live before ordering.