San Tan Tactical STT-15-6ARC 6mm ARC AR-15 with 18 in Carbon-Fiber-Wrapped Barrel, Ambidextrous Billet Receiver, 26+1
This San Tan Tactical STT-15-6ARC stands out as an early factory rifle chambered in 6mm ARC, built on an ambidextrous billet receiver and paired with an 18 in carbon-fiber-wrapped, threaded barrel topped by a multi-port brake/flash hider. It features a Rifle+ gas system tailored for this 18 in 6mm ARC configuration, a slick-side upper, and a free-float M-LOK handguard with a T-marked full-length Picatinny top rail. Made in the USA and marked Fort Worth, Texas, it comes with flip-up sights installed and two steel magazines.
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.
Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are minor scratches and small blemishes on exterior surfaces. The bore is clean and shiny.
What’s Included
- San Tan Tactical factory cardboard box with model/serial label (STT-15-6ARC)
- Factory fired test casing
- Flip-up iron sights (installed)
- 1x 26-round steel magazine marked 6.5 Grendel/6ARC
- 1x 20-round steel magazine marked 6.5 Grendel
The ambidextrous billet receiver integrates an ambi magazine release and ambi bolt catch/release, matched with an ambidextrous safety and an ambidextrous charging handle with an extended latch. An upper-to-lower tensioning screw and a trigger-creep adjustment screw are built in. The slick-side upper deletes the forward assist for a clean profile.
The 18 in carbon-fiber-wrapped barrel is threaded and fitted with a multi-port brake/flash hider. A Rifle+ gas system is configured specifically for the 18 in 6mm ARC setup, and the action is direct impingement for a traditional AR-15 operating system.
A free-float aluminum M-LOK handguard spans to a T-marked, full-length Picatinny top rail across the receiver and handguard. Flip-up front and rear iron sights are installed.
Controls and ergonomics include a flat-faced, single-stage trigger, a 6-position telescoping stock, and a Magpul MOE pistol grip. Receivers are machined from 7075-T651 aluminum and finished in Type III hardcoat anodizing with San Tan Tactical logos and a U.S. flag motif. Capacity is 26+1, and two steel magazines are included: one 26-round marked 6.5 Grendel/6ARC and one 20-round marked 6.5 Grendel.