Sig Sauer M400 5.56 NATO AR-15 Rifle, 16 in Barrel, Free-Float M-LOK Handguard Installed, 1:8 Twist, Threaded Muzzle, Black
This Sig Sauer M400 stands out for its excellent condition and thoughtful configuration. It features a non-SIG-brand free-float aluminum M-LOK handguard, a 16 in 5.56 NATO barrel with a 1:8 twist, and a threaded muzzle with a three-prong flash hider. The forged flat-top upper includes a T-marked Picatinny rail, and the rifle comes with a substantial magazine package from Mission First Tactical and Magpul.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: This rifle shows minimal markings from previous handling and use. The bore is bright and clean.
What's Included
- Sig Sauer M400 5.56mm NATO semi-automatic rifle
- Four 30-round magazines
- One 10-round magazine
- One Magpul PMAG Gen M3 AR/M4 magazine
The M400 is built on an AR-15 direct-impingement platform with a forged flat-top upper that carries a T-marked Picatinny rail. The upper includes a forward assist, case deflector, and ejection-port dust cover. Aluminum receivers wear a black hard-coat anodized finish and display factory rollmarks: upper marked "SIG SAUER SIGM400" and lower marked "SIG SAUER INC, NEWINGTON, NH, USA."
The 16 in barrel is chambered in 5.56 NATO and marked "5.56 NATO" and "1/8." It uses a 1:8 twist to stabilize a broad range of bullets and is threaded at the muzzle. A three-prong flash hider is installed.
A non-SIG-brand free-float aluminum M-LOK handguard is installed. This handguard provides M-LOK attachment slots while maintaining a free-floated barrel setup.
Furniture and controls include a 6-position adjustable polymer stock, SIG SAUER polymer pistol grip, and a single-stage curved trigger. The manual safety uses SAFE/FIRE pictograms and a non-ambidextrous selector. Length of pull is 14.0 in.
The rifle is configured with no sights and an optic-ready flat-top rail. Capacity is 30+1, and the magwell carries the round SIG logo.