SIG Sauer M400 TREAD 5.56 NATO AR-15, 16 in Stainless Threaded Barrel, Mid-Length Gas, Free-Float M-LOK, 30+1
The SIG Sauer M400 TREAD is a USA-made AR-15 pattern rifle configured with a 16-inch stainless, threaded barrel and a mid-length gas system. It features SIG's free-float aluminum TREAD M-LOK handguard with U.S. flag and TREAD logo, a flat-top upper with T-numbered Picatinny rail, and an adjustable 6-position stock. This example includes two 30-round PMAGs and installed M-LOK accessories.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The exterior shows scattered scratches and blemishes from prior handling. The bore is clean and shiny.
What's Included
- Two Magpul PMAG GEN M2 MOE 30-round polymer magazines (sealed packaging visible in photos)
- M-LOK angled hand stop (installed)
- M-LOK QD sling swivel socket (installed)
The 16-inch stainless steel barrel is threaded 1/2x28 and paired with a 1:8 twist, aligning with a mid-length gas system and low-profile gas block. This setup is built around a semi-automatic, direct-impingement action with a 30+1 capacity.
The free-float TREAD handguard is aluminum with M-LOK slots and displays both the TREAD logo and a U.S. flag. It arrives with an installed M-LOK angled hand stop and a QD sling socket, and the rifle uses a hard-coat anodized finish over aluminum receivers.
A flat-top upper receiver provides a T-numbered Picatinny rail for mounting. The rifle ships without sights and includes SIG SAUER-marked polymer pistol grip furniture, a 6-position collapsible stock, and a manual safety.
Made in the USA, this M400 TREAD sits within SIG Sauer's M400 series and includes two 30-round Magpul PMAG GEN M2 MOE magazines as listed.