San Tan Tactical's STT15 5.56x45mm AR-15 Rifle exemplifies precision and craftsmanship, designed for shooters who demand unmatched performance and reliability. Constructed with true matched, hand-finished pillar billet sets, this rifle offers superior strength and a refined fit. The STT15 lower is fully ambidextrous, providing versatility for all users and includes three QD attachment points for easy integration of accessories. The upper is crafted from a single block of 7075T6 Certified Aerospace Aluminum, ensuring exceptional durability and lightweight construction. Each critical component, including the bore, receiver extension face, barrel nut threads and barrel extension surfaces, is machined in one continuous operation, guaranteeing perfect concentricity and precise alignment with the barrel assembly. The receiver sets are hand-ground to ensure an optimal fit, flawless finish and long-term repeatable accuracy. Complementing the rifle is the San Tan 5.56x45mm barrel, machined from 41V50 vanadium steel with a 1:7 twist rate, threaded 1/2-28 and dimpled for precise gas block alignment and retention. This rifle is built to provide exceptional performance, shot after shot, making it the ultimate choice for any serious shooter. STT suppressor optimized enhanced bolt carrier group improves suppressor efficiency and longevity STT 5.56x45mm barrel for superior performance and accuracy Equipped with a CMC Triggers Flat 3.5lb single-stage drop-in trigger for crisp, consistent performance Magpul MOE grip and stock deliver ergonomic handling and stability for improved shooting performance M-LOK handguard ensures a secure and customizable attachment system for tactical enhancements Equipped with an ambidextrous charging handle for seamless operation from either side Mil-Spec 6-position buffer tube with H1 buffer provides recoil control and adjustability Precision CNC machined from Billet 7075-T6 certified aluminum for superior strength and durability Features extended feed ramps for reliable and consistent feeding Includes ambidextrous magazine and bolt release controls for improved functionality and ease of use The Type III, Class 2 deep black hardcoat anodized finish enhances both aesthetics and durability