STT15 5.56 AR15 Rifle

San Tan Tactical’s STT15 5.56 AR15 Rifle is built with our true matched, hand-finished pillar billet sets. The STT15 lower is fully ambidextrous and has three QD attachment points.

The upper is cut from a single solid 7075-T6 Certified Aerospace Aluminum block. Propriety special burnished bore that gives a compacted internal surface, resulting in a much smoother surface finish. The bore, receiver extension face, barrel nut threads, and barrel extension surfaces are all machined in one operation ensuring that they are perfectly concentric and perpendicular to the barrel assembly. Our receiver serial number matched sets are hand ground for optimal fit, finish, and long-term repeatable accuracy.

Adding to that the San Tan 5.56 barrel, machined from 41V50 vanadium steel with a 1:7 twist, ½-28 threaded end, and dimpled for gas block alignment and retention.

Built with the CMC AR15 3.5lb Single Stage Flat Bow Trigger. CMC Triggers is the original manufacturer of the Drop-in Trigger Group for the AR-15/10 rifle since 2003. CMC’s critical sear engagement surfaces have a proprietary machining process that renders superior surface finish and dimensional control. As compared to their competition, the techniques used to establish a 1-2 RMS surface finish as opposed to EDMing which leaves a pitty 32 RMS, compared to a mirror which is 0 RMS.

STT Enhanced Bolt Carrier Group – AR15 5.56 BCG rounds out the internals. Our BCG is 9310 case hardened steel, MPI, and HPT tested to 70,000 psi. It features three gas ports to bleed of excess gas encountered with suppressors and full auto tail is enlarged and chamfered to allow for faster center up in the buffer tube and to prevent carrier tilt. Finished in Desert Multicam Cerakote with a staked gas key.

Midwest Industries® combat rail gives the STT15 a full-length picatinny rail with M-LOK attachments all around for any attachment needs and two more QD sling points.