SIG Sauer M400 TREAD 5.56 NATO AR-15, 16-inch Stainless Barrel, Free-Float M-LOK Handguard, 1:8 Twist, 1/2x28 Threaded
The SIG Sauer M400 TREAD pairs a 16-inch stainless steel barrel and mid-length gas system with a free-floating aluminum M-LOK TREAD handguard, delivering a well-specified AR-15 configuration from the factory. Standout features include a forged flat-top upper with T-marked Picatinny rail, SIG three-prong flash hider, ambidextrous safety with pictogram markings, and a Magpul MOE SL-K adjustable carbine stock. Made in the USA, this example is in excellent condition and includes a 30-round Magpul PMAG magazine.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Specific Condition Notes: This rifle shows minimal prior handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
What’s Included
- SIG Sauer M400 TREAD rifle (5.56 NATO)
- 1x 30-round Magpul PMAG polymer magazine
The 16-inch stainless steel barrel features a 1:8 twist and a 1/2x28 threaded muzzle capped with a SIG three-prong flash hider. The mid-length gas system uses a pinned micro gas block for secure, consistent operation.
The forged flat-top upper includes a T-marked Picatinny rail, forward assist, and ejection-port dust cover. Receivers are forged aluminum with a hard-anodized finish for durability.
The free-floating aluminum M-LOK TREAD handguard uses a proprietary barrel nut secured by two clamping screws. It bears the TREAD logo and provides modern accessory mounting options while keeping weight forward-balanced.
Controls include an ambidextrous safety with clear pictogram selector markings. Furniture consists of a Magpul MOE SL-K carbine stock on a 6-position receiver extension, offering a length of pull adjustable from 10.25 to 13.5 inches. A SIG SAUER textured polymer pistol grip rounds out the setup.
This rifle is configured for 30+1 capacity in 5.56 NATO, ships with one 30-round PMAG, and is built in the USA. It comes without factory sights, allowing the user to tailor the sighting system to their needs.