The San Tan Tactical STT-15 (brand part no. STT-15-PILLAR-CMB) is a matched lower and upper receiver set built around San Tan Tactical’s Pillar ambidextrous design, machined from American-made materials. Because the set includes both receivers, builders get a matched pair rather than fitting a lower to a separately sourced upper. San Tan Tactical builds these using the highest-quality machines paired with domestic materials, aiming for a rifle built to last. It’s a solid option for builders who want ambidextrous function from a matched receiver set rather than mixing components.

Key Specifications

• Includes a matched lower and upper receiver in a single set.
• Built on the Pillar ambidextrous design.
• Machined from American-made materials.
• Rated multi-caliber, compatible with common AR-15 chamberings.
• Runs a semi-automatic action, standard for AR-15-pattern builds.
• Machined from aerospace-grade 7075-T6 aluminum for a lightweight, high-strength receiver set.
• The lower includes three QD sling attachment points for flexible mounting.
• Components are hand-finished and matched as a set for a tight, consistent fit.
• Fully ambidextrous, with mirrored controls for right- or left-handed shooters.

Frequently Asked Questions

Does this include both a lower and upper receiver? Yes, it’s a matched lower/upper receiver set.

Is it limited to one caliber? No, it’s rated multi-caliber for common AR-15 chamberings.

Buy the San Tan Tactical STT-15 Pillar Receiver Set

Build on a matched, ambidextrous receiver set made with American materials, part of our AR15 lowers selection. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.