SIG M400 ROSE 5.56 NATO 16″ W/ – ROMEO 5 GENII (2)30RD BLACK

SIG’s M400 ROSE 5.56 AR-15 is built for dependable performance across range sessions, home defense, and everyday carry-style preparedness setups. This configuration pairs a 16-inch 5.56 NATO barrel with a ROMEO5 GEN II red dot for rapid target acquisition. It also ships with two 30-round magazines—useful for training, competition-style drills, and consistent range logistics.

SIG M400 ROSE 5.56 AR-15 16″ with Romeo5 Gen II

The SIG M400 platform is engineered around modern sporting rifle ergonomics and a straightforward AR-15 operating system, offering a solid foundation for optics-driven use. With a 1:7 twist rate, this barrel is well-suited to stabilize commonly used 5.56 NATO bullet weights while maintaining compatibility with standard AR-pattern accessories. The included red dot supports practical sighting for defensive-oriented disciplines and quick-paced shooting.

Key Specifications

• Manufacturer is Sig Sauer.
• Manufacturer part number is RM400-16B-ROSE-R5X2.
• Action is semi-auto.
• ATF type is modern sporting rifle.
• Barrel length is 16 inches.
• Caliber is .223 REM/5.56 NATO.
• Magazine capacity is 30 rounds.
• Overall length is 43.5 inches.
• Magazine included is 2 x 30-round Magpul magazines.
• Product model is M400.
• Barrel finish is black.
• Rate of twist is 1:7″.
• Safety is ambidextrous.
• Thread pattern is 1/2″ x 28.
• UPC is 798681716593.

What’s Included

This SIG M400 ROSE package includes the rifle with the ROMEO5 Gen II optic and two 30-round black magazines, supporting immediate use for sight setup and range training with an AR-pattern platform.

The combination of a 16-inch 5.56 NATO barrel, a proven 1:7 twist, and a ready-to-use red dot makes this SIG M400 ROSE an efficient choice for buyers who want a modern, optic-forward AR-15 setup. The ambidextrous safety and standard thread interface improve usability and accessory flexibility, while the included magazines reduce friction when preparing for training and practice.

Frequently Asked Questions (FAQs)

• Is the SIG M400 ROSE chambered for .223 Remington or 5.56 NATO? Yes, it is chambered for .223 REM/5.56 NATO.
• What is the barrel twist rate on this model? The rate of twist is 1:7″.
• Does it include magazines, and how many rounds are they? Yes, it includes two 30-round magazines.
• Is a scope or red dot optic included? Yes, the package includes a ROMEO5 Gen II red dot.
• What is the barrel length? The barrel length is 16 inches.
• What is the thread pattern for accessories? The thread pattern is 1/2″ x 28.
• Is it compatible with standard AR-15 accessories? As an AR-pattern rifle, it is designed for use with compatible AR accessories, including optic and general-purpose AR components (always verify fitment with the specific accessory).
• Where can this item ship? The listing notes it does not allow direct shipment to California, Rhode Island, or Washington, so state-specific compliance rules apply.