Sig Sauer M400 SDI X Pistol | 5.56 NATO | 11.5″

The Sig Sauer M400 SDI X Pistol is a compact, instructor‑informed 5.56 NATO pistol designed for controllability and ambidextrous operation. It features an 11.5″ cold hammer‑forged chrome moly steel barrel, a free‑floating M-LOK handguard and a Magpul BSL telescoping pistol brace. Controls are fully ambidextrous and the two‑stage flat blade match trigger delivers a crisp pull for precise follow-up shots. For a practical optic solution under $1,000, a low‑profile red dot such as the Vortex Sparc AR pairs well with this platform for rapid target acquisition.

Recommended uses include range training and carbine-style competition where a compact, controllable 5.56 NATO pistol is beneficial.

Product Specifications

• The manufacturer is Sig Sauer.
• The manufacturer part number is PM400-SDI-11B-BLK.
• The model/series is M400 SDI X Pistol.
• The caliber is .223 Rem / 5.56 NATO.
• The barrel measures 11.5 inches.
• The barrel material and finish are chrome moly steel with Black FNC finish.
• The rate of twist is 1:7″.
• The action is semi-automatic.
• The overall length is 30.1 inches.
• The weight is 5.8 lb.
• The magazine capacity is 30 rounds and it includes one 30-round magazine.
• The handguard is a free-floating M-LOK handguard.
• The pistol uses a Magpul BSL telescoping pistol brace.
• The trigger is a 2-stage flat blade match (4.5–6.5 lb).
• The UPC is 798681698967.

The M400 SDI X Pistol brings instructor-driven design elements and ambidextrous controls into a compact 11.5″ package. The combination of a rigid free-floating M-LOK handguard, match-grade trigger, and a cold hammer-forged barrel make this a pragmatic choice for shooters who want a controllable, accessory-forward platform for range work and competition. Its compact footprint and included 30-round magazine provide extended shooting between reloads while staying suitable for short-barrel carbine configurations.

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