Sig Sauer M400 TREAD 5.56 NATO AR-15, 16-inch Stainless Barrel, Mid-Length Gas, Free-Float M-LOK, Optics-Ready, U.S. Flag Engraving
This Sig Sauer M400 TREAD stands out with a 16-inch stainless steel barrel, a mid-length gas system, and an approximately 15-inch free-float aluminum M-LOK handguard. It is optics-ready and features a distinctive engraved U.S. flag panel on the handguard. The rifle is in excellent condition with a clean, mirror bore and comes with two 30-round PMAG GEN M3 magazines and an installed Magpul M-LOK MVG vertical foregrip.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The rifle shows minimal evidence of prior handling or use. The bore presents a bright, reflective interior.
What’s Included
- Sig Sauer M400 TREAD 5.56mm NATO semi-automatic rifle
- 2x 30-round Magpul PMAG GEN M3 polymer magazines
- Magpul M-LOK MVG vertical foregrip (installed)
The M400 TREAD uses an aluminum receiver set paired with an approximately 15-inch free-float aluminum M-LOK handguard, providing extensive mounting space. A T-marked Picatinny rail runs along the upper receiver, and the rifle ships optics-ready with no sights installed.
The 16-inch stainless steel barrel features a 1:8 twist and is threaded at the muzzle, fitted with a three-prong flash hider. The mid-length gas system supports smooth operation with 5.56mm NATO ammunition.
Furniture includes a Magpul MOE SL-K 6-position adjustable stock and a SIG SAUER polymer pistol grip. A manual safety is present, and the rifle offers a 30+1 capacity. The installed Magpul M-LOK MVG vertical foregrip adds ready-to-use control on the handguard.
Markings include SIG SAUER INC NEWINGTON NH, USA; SIG SAUER SIGM400; and a SIG circular logo above the magazine well. An engraved U.S. flag panel on the left side of the handguard provides a distinctive visual detail.