Sig Sauer M400 SDI-X Semi-Automatic Rifle 5.56NATO 16" Barrel (1)-30Rd Magazine 6 Position Magpul SL Stock Flat Dark Earth Cerakote Finish
The M400-SDI X was designed to meet the highest standards of performance and reliability. From the rifle's full suite of ambidextrous controls to its proven mid-length gas system. Features fully Ambi Controls- safety, charging handle, bolt Catch & mag release; 2-Stage Matchlite Duo trigger; free floating M-LOK; mid-length direct impingement operating system and 6 position Magpul SL stock.
Brand: Sig Sauer
Category: Tactical Rifles
Series: SDI-X
Model: M400
Caliber: 5.56 NATO
Barrel Length Range: 16" to 16.99"
Gun Platform: AR-Style
Operating System: Direct Impingement
Stock Finish Group: Black
Capacity: 30+1
Stock Material: Synthetic
Action: Semi-Auto
Oal: 33.25' - 36.50"
Hand: Ambidextrous
Sights: None
Barrel Finish: Black
Barrel Material: Chrome Moly Steel
Muzzle: Sig Flash Hider-Compensator
Twist: 1:7"
Receiver Description: Picatinny Rail
Magazine Type: AR-15
Grips: Reduced Angle
Handguards: M-LOK
Height: 7.10"
Receiver Material: Aluminum
Safety: Lever
Thread Pattern: 1 / 2"x28
Width: 2.75"
Stock Description: 6 Position Magpul SL
Barrel Description: Threaded
Barrel Length: 16"
Max Capacity: 30
Receiver Finish: Flat Dark Earth Cerakote
Trigger: Sig Two-Stage Matchlite Duo
Weight: 7 lbs
Stock Finish: Black
Handguard Finish: Flat Dark Earth
Caliber Dictionary
The Below Information Has Been Provided From Our Gun Caliber Dictionary And Is Meant For Informational Purposes Only. It Is Not Intended to Describe The Unique Specifications For This Ammunition.
The 5.56X45mm NATO cartridge was designed by James Sullivan, a member of Eugene Stoner's engineering team that developed both the M16 rifle and its original cartridge. The 5.56X45mm NATO was adopted by the U.S. military in 1964 and by NATO in 1980. With bullet diameter of .224-inch, the original M193 military cartridge used a 55-grain bullet at 3250 fps; the current M855A1 cartridge, developed by FN, uses a 62.5-grain bullet at 3020 fps, offering greater range and better penetration. The civilian version of the 5.56X45mm is 223 Remington; the cartridges are dimensionally identical but military chamber dimensions and specifications for military brass are different. It is considered safe to use 223 Remington ammo in a 5.56X45MM NATO chamber, but not a good idea to use 5.56X45mm ammo in a rifle specifically chambered for the 223 Remington. Although the stopping power of .22-caliber bullets remains controversial the 5.56X45mm has served well in now multiple generations of M16 rifles. — Craig Boddington
