SIG Sauer SIGM400

The SIGM400 is a family of firearms manufactured by SIG Sauer.^[1] The M400 is an air-cooled, direct impingement gas-operated, magazine-fed carbine that is based on the earlier AR-15 rifle.^[2] Depending on the variant, it can be chambered for 5.56×45mm NATO or .300 AAC Blackout cartridges, and may have a fixed or telescoping stock.^[3]

SIG Sauer SIGM400 series
Sig Sauer M400 series rifle
Type	Semi-automatic rifle Carbine
Place of origin	United States
Service history
In service	2011–Present
Used by	See Users
Wars	War in Iraq (2013–2017) Islamic State insurgency in Iraq (2017–present)
Production history
Designed	2000s
Manufacturer	SIG Sauer
Produced	2011–Present
Specifications
Mass	7.6 pounds (3.4 kg)
Barrel length	14.5–20 inches (37–51 cm) (5.56×45mm) 9–16 inches (23–41 cm) (.300 AAC)
Cartridge	5.56×45mm NATO .223 Remington .300 AAC Blackout
Action	Direct gas impingement system, rotating bolt
Feed system	STANAG magazines

Design details

Operating mechanism

The SIGM400 is a semi-automatic firearm in either rifle as the SIGM400 Classic, SRP, Tread, Elite, Predator or pistol as the Elite PSB, intended for law enforcement, military and civilian markets. It fires from a closed bolt and uses a direct impingement gas system.^[3]

Features

The SIGM400 Predator is a rifle while the SIGPM400 Elite PSB is a pistol. The rifles are chambered for either 5.56×45mm NATO with 14.5-inch (37 cm), 16-inch (41 cm), 18-inch (46 cm), or 20-inch (51 cm) barrels threaded 1/2x28, or chambered for .300 AAC Blackout with 9-inch (23 cm) or 16-inch (41 cm) barrels which are threaded 5/8x24 for muzzle devices such as sound suppressors. There are California compliant ("featureless") models for both.^[3] The .300 AAC Blackout model is tailored specifically for efficient use with suppressors. The Picatinny rail supports optical, electro optical, or iron sights. SIG Sauer also manufactures suitable suppressors.

The SIGPM400 Elite PSB pistol is chambered for 5.56×45mm NATO with an 11.5-inch (29 cm) barrel and is chambered for .300 AAC Blackout with a 9-inch (23 cm) barrel. Both use a Pistol Stabilizing Brace accessory.^[3]

A map with users of the SIGM400 in blue

Users

•  Brazil Civil Police of Rio de Janeiro State^[4]
•  Egypt: Egyptian Special Forces Sa'ka, Navy Sa'ka And paratroopers
•  Iraq: Iraqi Special Operations Forces use the SIG Sauer M400.^[5]
•  Oman: Oman Military use the SIG Sauer M400.^[6]
•  Philippines: Philippine Army used as a Designated Marksman Rifle.^[7][8]
•  United States: US Military, Philadelphia Police Department, Detroit Police Department SWAT, Franklin County, Ohio Police Department, California Highway Patrol, Indiana State Police, Vermont State Police, Virginia State Police use the SIG Sauer M400.^[9][10]

See also

• Heckler & Koch HK416
• SIG Sauer SIG516
• SIG MCX
• M4 carbine