Firearms

SIG Sauer M400 SDI 5.56x45mm 16-inch

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Specifications

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Notable Variants

Aftermarket Ecosystem

Historically Significant Examples

Serial Number Data

Production data from factory records and collector research. Year ranges are approximate for pre-1968 firearms.

Years	Serial Range	Count	Factory	Country	Confidence

Special Duty Instrument configuration M400 with enhanced mil-spec components, extended handguard, and SIG Romeo red dot package.

Type: Rifle

Action: Semi-automatic

Caliber: 5.56x45mm

Capacity: 30

Year introduced: 2021, Germany/USA

Weight: 110 oz

Overall length: 32.5"

Status: Active

Intended use: Patrol