The San Tan Tactical STT15 5.56x45mm AR-15 Rifle is crafted with precision and durability in mind. Featuring true matched, hand-finished pillar billet sets, this rifle is built for exceptional performance. The STT15 lower receiver is fully ambidextrous, providing versatility for both left and right-handed shooters and includes three QD attachment points for easy customization. The upper receiver is precision-machined from a single block of 7075T6 Certified Aerospace Aluminum, ensuring exceptional strength and lightweight design. All critical components, including the bore, receiver extension face, barrel nut threads and barrel extension surfaces, are machined in a single operation, guaranteeing perfect concentricity and precision alignment with the barrel assembly. Our serial-number-matched receiver sets are hand-ground to ensure optimal fit, finish and long-term repeatable accuracy. The San Tan 5.56x45mm barrel is crafted from high-quality 41V50 vanadium steel, featuring a 1:7 twist, 1/2-28 threading and dimples for gas block alignment and retention. The STT15 rifle combines top-tier craftsmanship, reliability and performance, making it the ideal choice for any 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 A Type III, Class 2 hardcoat anodized olive drab green finish offers a rugged and tactical appearance