M400 Tread
SIG Sauer · Carbine · In Production · 2018
Also known as: SIG M400 Tread, M400 TREAD
Overview
The M400 Tread is a semi-automatic carbine chambered in 5.56x45mm NATO, produced by SIG Sauer since 2018. Featuring a 30-round magazine capacity, this carbine offers generous firepower for duty use and home defense.
Specifications
| Weight (empty) | 3175 g (112.0 oz) |
| Weight (loaded) | 3615 g (127.5 oz) |
| Overall Length | 782 mm (30.79") |
| Barrel Length | 406 mm (15.98") |
| Action Type | Gas Operated Direct Impingement |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Trigger Pull | 29 N (6.5 lbf) |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 905 m/s (2969 fps) |
| Muzzle Energy | 1640 J (1210 ft·lbf) |
| Effective Range | 500 m (547 yd) |
| Maximum Range | 3600 m (3937 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 203 mm (7.99") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Stainless Steel |
| Stock Material | Polymer |
| Finish | Hard Coat Anodized |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as 5.56mm NATO, 5.56x45mm, .223 Remington
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety Selector, Ambidextrous Safety
- Features: Free Float Handguard, M Lok Mounting, Ambidextrous Controls, Single Stage Trigger, Mid Length Gas System, Flat Top Receiver, Picatinny Rail, Magpul Stock, Low Profile Gas Block
Variants
- M400 Tread V2 — Modernized
- M400 Tread Pistol — Pistol
- M400 Tread Predator — Precision
Service history
Operators
- United States Law Enforcement
- Civilian Sport Shooters
Production
Production years: 2018-present
Exact production numbers not disclosed by SIG Sauer. The M400 Tread line has become a popular mid-range AR-15 option in the civilian market.
Origin
Country of origin: United States
Designer: Eugene Stoner
Notes
The M400 Tread is built on SIG Sauer's decade-plus experience with the M400 series, first introduced in 2010. The Tread variant distinguishes itself through its focus on modularity and value without compromising quality. The 1:8 twist rate barrel stabilizes a wider range of bullet weights (55-77 grains) compared to older 1:9 twist barrels, making it more versatile for modern ammunition. The mid-length gas system provides a longer dwell time compared to carbine-length systems, resulting in softer recoil and less wear on internal components. SIG Sauer manufactures the M400 Tread at their Newington, New Hampshire facility. The rifle's thread pattern (1/2-28 TPI) accepts standard muzzle devices. The Tread line has expanded to include pistol variants, predator hunting models, and enhanced V2 versions. Ambidextrous controls include charging handle and safety selector, enhancing usability for left-handed shooters.
Background
When SIG Sauer unveiled the M400 Tread in October 2018, they positioned it as 'The New Face of Freedom,' a direct nod to the Gadsden flag's revolutionary spirit. The timing was deliberate-launching in an era of increasing political tension around firearms, SIG made a statement that American-made quality and liberty could coexist with affordability, challenging the notion that premium performance required premium pricing.