San Tan Tactical's STT15 5.56x45mm AR-15 Rifle combines precision engineering and unmatched craftsmanship, designed to deliver exceptional performance for any shooter. The rifle is constructed using true matched, hand-finished pillar billet sets that ensure maximum strength and durability. The STT15 lower is fully ambidextrous, featuring three QD attachment points for versatile customization and ease of use. The upper receiver is machined from a solid piece of 7075T6 Certified Aerospace Aluminum, offering both superior strength and a lightweight design. Each critical component, including the bore, receiver extension face, barrel nut threads and barrel extension surfaces, is meticulously machined in a single operation to guarantee perfect concentricity and precise alignment with the barrel assembly. The receiver sets are serial number matched and hand-ground, providing an optimal fit and finish for long-lasting accuracy and reliability. Completing this high-performance package is the San Tan 5.56x45mm barrel, crafted from 41V50 vanadium steel with a 1:7 twist, threaded 1/2-28 and dimpled for secure gas block alignment and retention. The STT15 rifle is a powerful combination of precision, reliability and performance, ideal for both professional and recreational shooters. 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 A Type III, Class 2 hardcoat anodized black finish provides superior durability Desert multicam CeraKote finish enhances durability while providing a rugged, tactical look