The Sig Sauer M400 Tread Pistol (Sig part no. SIG PM400-11B-TRD-V2) brings Sig’s popular Tread series to a 5.56 NATO AR pistol platform. An 11.5-inch chrome-lined barrel with a 1:7 twist rate delivers durability and consistent accuracy across a wide range of bullet weights, and the M-LOK handguard keeps accessory mounting clean and modular. Ambidextrous controls make the M400 Tread fast and intuitive to run from either shoulder, and the pistol ships with a Magpul BSL brace and one 30-round magazine ready to load. Finished in black by Sig Sauer, this M400 Tread is built for shooters who want proven Sig engineering at an approachable price point.

Key Specifications

• Chambered in 5.56 NATO/.223 Remington, one of the most versatile centerfire rifle cartridges available.
• Runs an 11.5-inch chrome-lined barrel for durability and consistent accuracy.
• Holds 30 rounds per magazine, and ships with 1 30-round magazine included.
• Uses a 1:7 twist rate to stabilize a wide range of 5.56 bullet weights.
• Wears an M-LOK handguard for a clean, modular accessory-mounting surface.
• Ships with the Magpul BSL brace installed for a stable shooting platform.
• Features ambidextrous controls for fast manipulation from either side.
• Ships optics-ready with no fixed sights, leaving the top rail open for a red dot.
• Finished in black for a tough, low-maintenance exterior.

Frequently Asked Questions

Does this pistol come with a brace? Yes, the Magpul BSL brace ships installed on the M400 Tread.

What handguard does it wear? An M-LOK handguard for clean, modular accessory mounting.

Is this pistol optics-ready? Yes, it ships with no fixed sights so you can mount a red dot directly to the top rail.

Buy the Sig Sauer M400 Tread Pistol, 5.56 NATO, 11.5-Inch, M-LOK, Black

The M400 Tread brings Sig’s approachable, no-frills engineering to an AR pistol platform, complete with a brace and magazine ready to go out of the box. Order it from our AR pistols lineup at our Lubbock, Texas gun shop for fast, insured shipping to your FFL.