The SIG Sauer M400 Tread Rifle (SIG part no. RM40016BTRDV2CON) is finished in a distinctive Concrete color and built around a 16-inch barrel with a 1:8 twist rate for reliable 5.56 NATO performance. It’s also safe to run .223 Remington through the same chamber, giving owners flexibility with ammunition choice. The rifle ships with a 30-round magazine and a stainless steel adjustable Magpul stock that lets you dial in length of pull for a range of shooters. Built without fixed sights, it’s ready for the optic of your choice right out of the box, making it a strong foundation for a home-defense rifle, range gun, or first AR-15 build.

Key Specifications

• Chambered in 5.56 NATO for reliable AR-15 performance.
• Also safely fires .223 Remington ammunition through the same chamber.
• Ships with a 30-round magazine.
• 16-inch barrel balances maneuverability with reliable 5.56 velocity.
• Rifling twist rate of 1:8 stabilizes a wide range of bullet weights.
• Equipped with a stainless steel adjustable Magpul stock for a custom length of pull.
• Ships without fixed iron sights, leaving the top rail open for the optic of your choice.
• Semi-automatic action cycles with each trigger pull for fast follow-up shots.
• Ships at approximately 8.7 pounds.
• Finished in a distinctive Concrete color.

Frequently Asked Questions

What caliber does this rifle chamber? 5.56 NATO, also safe for .223 Remington.

Does it come with sights? No fixed iron sights are included, so the top rail is open for mounting your own optic.

What kind of stock does it use? A stainless steel adjustable Magpul stock, letting you dial in your length of pull.

Buy the SIG Sauer M400 Tread Rifle

Want a SIG-built AR-15 with a finish that stands out? Order this SIG Sauer rifle from our AR rifles lineup and we’ll ship it fast and insured to your local FFL from our Lubbock, Texas shop.