San Tan Tactical STT-15 Upper Receiver 223 Rem/5.56 NATO – Flat Top, Black (STT-PILLAR-1)

• Upper receiver designed for 223 Remington and 556 NATO rifle platform assemblies
• Constructed from 7075 T651 aerospace grade aluminum billet for strength and durability
• Features M4 feed ramps supporting reliable cartridge feeding during firearm operation
• Type III Class II hard coat anodized finish enhances wear resistance and corrosion protection
• Flat top configuration allows mounting of optics and accessory rail systems
• Designed for long gun builds requiring precision machined upper receiver components

The San Tan Tactical STT-15 Upper Receiver is an upper receiver designed for housing and aligning components in AR-style rifle platforms.

The San Tan Tactical STT-15 Upper Receiver is machined from 7075-T651 billet aluminum and features M4 feed ramps with a Type III Class II hard coat anodized black finish. This upper receiver is used for supporting barrel, bolt carrier group, and handguard alignment in .223 Remington and 5.56 NATO configurations. It is categorized under upper receivers and includes a flat top design for mounting optics or sights. In standard configurations, the component interfaces with compatible lower receivers and AR-pattern parts. The product type upper receiver provides a structural platform for rifle assembly, and the San Tan Tactical STT-15 Upper Receiver is intended for firearm builds or replacement where a billet upper receiver is specified.