Sig Sauer M400 Tread AR-15 Semi Auto Rifle 5.56 NATO MLOK Handguard

The Sig Sauer M400 Tread AR-15 Rifle is an exemplary choice for both new firearm owners and seasoned enthusiasts seeking a reliable, customizable, and high-performance modern sporting rifle.

Engineered by Sig Sauer, a brand synonymous with quality and innovation in the firearms industry, the M400 Tread is designed to offer an exceptional shooting experience right out of the box, while also serving as a perfect platform for future upgrades and personalization.

Whether you're looking for a dependable rifle for home defense, a versatile platform for competitive shooting, or an accurate tool for target practice and varmint control, the M400 Tread delivers. Its robust construction, thoughtful ergonomics, and precision-engineered components make it a standout option in the crowded AR-15 market. What makes this rifle truly special for a wide range of users? It's the meticulous balance of user-friendly features, durable materials, and performance-driven design, all available through reputable dealers like DEGuns.

Unpacking the Core: What Makes the M400 Tread Stand Out?

The Sig Sauer M400 Tread is not just another AR-15; it's a testament to Sig Sauer's commitment to excellence. This rifle is built around a direct gas impingement system, known for its simplicity and accuracy potential, and chambered in the widely popular 5.56 NATO caliber, which also readily accepts .223 Remington ammunition. This dual compatibility provides shooters with flexibility in ammunition choice, making it ideal for various applications from training to hunting.

At its heart, the M400 Tread boasts a 16-inch stainless steel barrel, meticulously crafted with a matte bead blasted finish. This barrel length is considered a sweet spot for AR-15s, offering a balance of maneuverability and ballistic performance. The 1:8-inch twist rate is particularly versatile, stabilizing a wide range of bullet weights commonly used in 5.56 NATO and .223 Remington, ensuring consistent accuracy across different ammunition types. The barrel is also threaded 1/2"x28, a standard AR-15 thread pattern, allowing for easy attachment of muzzle devices. The included 3-chamber compensator is a significant feature, actively reducing felt recoil and muzzle rise, which translates to faster follow-up shots and improved accuracy, especially during rapid firing sequences.

Built for Durability: Receiver and Gas System Excellence

The foundation of the M400 Tread's robustness lies in its forged aluminum upper and lower receivers. Forging is a manufacturing process that aligns the grain structure of the metal, resulting in components that are inherently stronger and more durable than those made through casting or machining alone. This ensures the rifle can withstand rigorous use and provide long-term reliability.

The upper receiver features an integral MIL-STD 1913 accessory rail, often referred to as a Picatinny rail. This standardized rail provides a stable and secure mounting platform for a vast array of optics, including red dot sights, holographic sights, traditional scopes, and backup iron sights. This "optics ready" design means users can immediately equip their preferred sighting system without needing additional adapters.

The direct gas impingement (DI) system utilized by the M400 Tread is a classic AR-15 design. How does it work? Gas is tapped from the barrel after the bullet passes a port, routed through a gas tube, and directed back into the bolt carrier group. This gas directly pushes the bolt carrier rearward, cycling the action. This system is praised for its elegant simplicity, lighter weight compared to piston systems, and its contribution to the rifle's inherent accuracy by keeping barrel harmonics undisturbed by moving parts external to the barrel itself. The mid-length gas system further refines this by offering a smoother recoil impulse compared to carbine-length systems, contributing to a more comfortable shooting experience.

Ergonomics and Customization: Designed for the Shooter

Understanding that an AR-15 should adapt to the shooter, not the other way around, Sig Sauer equipped the M400 Tread with several user-centric features. The free-float M-LOK compatible handguard is a prime example. Unlike traditional handguards that can put pressure on the barrel and negatively impact accuracy, a free-float design ensures the barrel is only connected to the receiver, allowing it to "free float" and resonate consistently, enhancing precision. The M-LOK system itself is a modern, modular attachment interface that allows users to easily and securely mount accessories like lights, lasers, foregrips, and bipods directly to the handguard. This system is lighter and more streamlined than quad rails, offering a comfortable grip and vast customization potential without unnecessary bulk.

The rifle also features a single-stage polished hard coat trigger. A good trigger is crucial for accuracy and shot control. This particular trigger is designed to offer a crisp, clean break, minimizing creep and overtravel, which allows shooters to maintain their sight picture and execute precise shots more effectively. The "polished hard coat" indicates a durable finish that contributes to a smoother pull and consistent feel over time.

Ambidextrous controls are a significant advantage, catering to both right-handed and left-handed shooters, as well as enabling faster manipulation during dynamic shooting scenarios. The M400 Tread includes an ambidextrous fire control selector and magazine catch, ensuring seamless operation regardless of the shooter's dominant hand or shooting position. The ambidextrous charging handle further enhances this, allowing for quick and easy cycling of the action from either side of the rifle.

For comfort and adaptability, the Magpul SL-K 6-position telescoping stock is a lightweight and ergonomic choice. This stock allows users to quickly adjust the length of pull to fit their individual body size, shooting stance, or even accommodate varying layers of clothing or body armor. Its compact design is ideal for storage and maneuverability. Complementing this is the SIG Sauer Pistol Grip, designed for a comfortable and secure hold, promoting better weapon control and reducing fatigue during extended shooting sessions.

Performance in Practice: Where the M400 Tread Shines

Target Shooting and Precision:
For enthusiasts who spend their weekends at the range, the M400 Tread offers consistent performance. The stainless steel barrel with its optimal twist rate, combined with the free-float handguard and refined trigger, contributes to excellent inherent accuracy. Shooters can expect tight groupings and predictable shot placement, making it a joy for plinking or honing marksmanship skills.

Home Defense and Reliability:
When it comes to personal and home defense, reliability is paramount. The M400 Tread’s direct gas impingement system, forged receivers, and quality components ensure dependable cycling, even in stressful situations. The rifle's manageable recoil due to the compensator, coupled with the adjustable stock and ambidextrous controls, makes it an accessible and effective tool for self-protection. Its standard AR-15 magazine compatibility means a wide array of readily available 30-round polymer magazines can be used, ensuring ample capacity.

Sporting and Hunting Applications:
The M400 Tread’s versatility extends to sporting applications and small game/varmint hunting. The 5.56 NATO/.223 Remington cartridge is well-suited for ethical harvesting of varmints like coyotes and groundhogs. Its relatively lightweight design at 7 lbs, coupled with an overall length of 30.8 inches (collapsed stock), makes it easy to maneuver in the field.

Essential Accessories and Upgrades

One of the greatest appeals of the AR-15 platform, and specifically the Sig Sauer M400 Tread, is its modularity. The rifle comes "optics ready," meaning you'll want to add a sighting system. Popular choices include:

• Red Dot Sights: Ideal for fast target acquisition at closer ranges, perfect for home defense and sport shooting.
• LPVOs (Low Power Variable Optics): Offer versatility with a wide magnification range (e.g., 1-6x or 1-8x), suitable for both close-quarters and medium-range engagements.
• Traditional Scopes: For maximum precision at longer distances.

Beyond optics, the M-LOK handguard opens up a world of accessories:

• Tactical Lights: Essential for low-light situations, especially for home defense.
• Lasers: For rapid aiming or passive aiming with night vision.
• Vertical or Angled Foregrips: To enhance ergonomics and control.
• Bipods: For stable shooting from a prone position or bench rest.

Additionally, owners might consider upgrading the sling (the rifle offers various attachment points), a different muzzle device (flash hider or suppressor), or even further fine-tuning the trigger with aftermarket options, though the stock trigger is already excellent. All necessary magazines and compatible accessories can be found at DEGuns.

Understanding Firearm Sights

The Sig Sauer M400 Tread AR-15 rifle features integrated MIL-STD 1913 rails on the upper receiver. These rails are designed to accommodate a variety of sighting systems, both optical and fixed. While many users will opt for an optical device, understanding traditional iron sights, if you choose to add them, is crucial.

Should you decide to add fixed iron sights, they are designed to provide a simple, durable sighting solution if your primary optical device fails or for close-range engagements. Adjustable rear sights often have different apertures for varying ranges:

• Short Range Aperture: This larger aperture is typically used for targets within 0-200 meters. It's designed for rapid target acquisition in close quarters. On some systems, this larger aperture is used when the rear sight is fully depressed or "zeroed" for the closest distance.
• Normal Range Aperture: This smaller, unmarked aperture is used for most firing situations and provides more precision. It is used in conjunction with an elevation knob to adjust for targets at distances like 300, 400, 500, or 600 meters, allowing for more precise bullet drop compensation.

Caring for Your Sig Sauer M400 Tread

Proper maintenance is key to the longevity and reliability of any firearm. The M400 Tread, like all AR-15s, benefits from regular cleaning, especially after each shooting session. This includes cleaning the bore, bolt carrier group, and lubricating key friction points. Following the guidelines in the owner's manual (available via the link below) will ensure your rifle remains in peak operating condition, providing years of reliable service.

In conclusion, the Sig Sauer M400 Tread AR-15 rifle (UPC 798681597765) represents a fantastic value proposition. It combines Sig Sauer's renowned quality and innovative design with the enduring versatility of the AR-15 platform. Its "optics ready" nature, ambidextrous controls, free-float M-LOK handguard, and excellent trigger make it an adaptable and high-performing rifle for a wide array of shooting disciplines. For anyone seeking a robust, reliable, and highly customizable AR-15, the M400 Tread is an outstanding choice, readily available from trusted retailers like DEGuns.

Sig Sauer M400 Tread AR-15 Specifications and Features

Owner's Manual

For detailed instructions on operation, maintenance, and safety, please refer to the official owner's manual:
M400 TREAD Manual