Lower Receivers

Complete AR-15 lower receiver built on the Shield Arms SA-4 7075-T6 billet lower receiver. Equipped with Match Nickel PTFE Trigger, Radian Weapons Talon Ambidextrous Safety Selector, B5 Systems BRAVO Stock, and B5 Systems Type 23 Pistol Grip. Features upper tension screw, threaded bolt catch pin, and beveled mag well. CNC machined in Bigfork, Montana. Lifetime warranty.

Complete AR-15 lower receiver with patented built-in folding mechanism for compact storage. Features 7075-T6 billet construction, B5 Bravo stock, Enhanced Nickel Teflon Trigger, and saves .5+ lbs compared to adapter-based folding systems.

Built-in folding AR-15 lower receiver with SBA3 brace. Precision machined 7075-T6 aluminum, saves 0.5+ lbs vs adapters. Made in USA with lifetime warranty.

Patented SA-15 Stripped Folding Lower Receiver. No adapter required - revolutionary folding mechanism built into the receiver. 7075-T6 billet aluminum construction. Build your custom folding AR-15 rifle or pistol. Made in USA with lifetime warranty.

The SA-4 Non-Folding Stripped Billet Lower Receiver is CNC-machined from 7075-T6 aircraft-grade aluminum billet to mil-spec dimensions and finished to Mil 8625 Type 3 Class 2 hard-coat anodizing. Builder-friendly features include a threaded bolt catch pin and built-in upper tension screw—hardware included. Marked MULTI. Compatible with standard mil-spec AR-15 lower parts kits and the majority of aftermarket components. Made in Bigfork, Montana. Lifetime warranty.

Build your own custom folding AR-15 with Shield Arms SA-15 Builders Kit. Features patented Folding Lower Receiver with integrated folding mechanism - no adapter required. Includes 7075-T6 billet upper and lower receivers, 15" M-LOK handguard, carbine buffer tube, proprietary H2 buffer, and thread locker. Lighter, stronger, and more compact than traditional folding adapter systems. Custom in-house Cerakote in Black, Fallout, Montana Mud, or Pineland. Made in USA with lifetime warranty.

AR-15 builder combo including Shield Arms SA-4 Forged Mil-Spec Lower Receiver, Mil-Spec Forged Upper Receiver, Radian Weapons Raptor-LT Ambidextrous Charging Handle, Radian Weapons Talon Ambidextrous Safety Selector, and Radian Weapons Ultralight AR-15 QD End Plate. Lifetime warranty on SA-4 lower.

The SA-9 Gen2 is Shield Arms' patented folding lower receiver machined from 7075-T6 billet aluminum, designed to accept Glock double-stack 9mm magazines with integrated last-round bolt hold open and enhanced parts compatibility.

Complete AR-15 lower receiver built on the Shield Arms SA-4 7075-T6 billet lower receiver. Upgraded with Nickel PTFE Trigger, B5 Systems BRAVO Stock, and B5 Systems Type 23 Pistol Grip. Features upper tension screw, threaded bolt catch pin, and beveled mag well. CNC machined in Bigfork, Montana. Lifetime warranty.

The Shield Arms Mil-Standard Complete SA-4 Non-Folding Lower is a fully assembled AR-15 lower receiver built on the SA-4 billet lower receiver, and equipped with a mil-spec trigger group, A2 grip, M4 stock, and mil-spec safety selector. Features a built-in upper tension screw and threaded bolt catch pin with hardware included. Marked MULTI. Ready to accept any mil-spec AR-15 upper receiver. Made in Bigfork, Montana. Lifetime warranty.