Sig Sauer M400 Tread 5.56 NATO 16" - AR-15 Rifle

Built to work and priced to own, the Sig Sauer M400 Tread 5.56 NATO 16" brings dependable 5.56 NATO performance to the AR-15 platform without the premium cost of boutique manufacturers or the compromises of budget builds.

The Sig Sauer M400 Tread 5.56 NATO 16" is a semi-automatic AR-15 rifle chambered in 5.56 NATO, built around direct impingement operation for reliable cycling on the AR-15 platform.

Proven Gas System: Running a direct impingement system that has proven itself across millions of rounds in the field, this 5.56 NATO platform brings that reliability record to every range session and defensive use case.

Well-Balanced Profile: The 16" barrel and M-LOK free-float handguard combination keep this rifle handy without sacrificing the sight radius and velocity that make the 5.56 NATO cartridge effective.

AR-15 Ecosystem Access: Standard AR-15 compatibility means accessories, replacement parts, and upgrade components are universally available — this rifle will never be an orphan platform.

Low-Maintenance Reliability: A quality finish and properly spec'd components reduce maintenance requirements without cutting corners on durability — more time shooting, less time cleaning.

• Caliber: 5.56 NATO
• Barrel Length: 16"
• Gas System: Direct Impingement
• Handguard: M-Lok Free-Float
• Muzzle Threading: 1/2x28
• Magazine Capacity: 10 Round
• Finish: Type III Hardcoat Anodized
• Origin: Made in the USA

Accepts all STANAG-pattern 5.56 NATO magazines and pairs with any mil-spec AR-15 lower receiver. Compatible with standard carbine buffer systems and mil-spec lower parts kits.

Receivers are machined from 7075 aluminum and finished with Type III Hardcoat Anodized, providing lasting corrosion and wear resistance under regular use and varied environmental conditions.

A practical choice for 3-gun competition, recreational plinking, home defense, and general-purpose utility. Works equally well as a first AR-15 or as a quality addition to an existing collection.

SIG SAUER is trusted by the U.S. military and law enforcement agencies worldwide. Their AR-15 lineup delivers the same premium quality and engineering that earned SIG that trust. Made in the USA.