The Radian Weapons Model 1 Builder Kit (part no. R0403) pairs a precision CNC-machined billet upper receiver and matching 15.5-inch Magpul M-LOK handguard with the AX556 lower receiver, structurally reinforced in critical areas for improved strength and rigidity. Cut from 7075-T6 aluminum, the upper ships assembled with a dust cover and is built optic-ready from the factory. It is a semi-complete kit for shooters who want a matched, reinforced upper and handguard set without machining tolerances that vary between separately sourced parts.

Key Specifications

• Includes a billet 7075-T6 aluminum upper receiver, precision CNC machined as a matching set with the handguard.
• Structurally reinforced in critical areas for improved strength and rigidity.
• Paired with the Radian AX556 lower receiver for a matched upper/lower set.
• Fitted with a 15.5-inch Magpul M-LOK handguard for accessory and light mounting space.
• Built optic-ready from the factory.
• Sold as a semi-complete kit, chambered on a multi-caliber platform.
• Ships at a 5.95-pound shipping weight as a bundled builder kit.
• Includes a Radian Raptor-SD ambidextrous charging handle for fast, symmetrical manipulation.
• Fitted with a Radian Talon 45/90 ambidextrous safety selector and ambidextrous bolt catch and release.

Frequently Asked Questions

What does semi-complete mean for this kit? The upper, handguard, and AX556 lower are matched and largely assembled, though it is not a fully built rifle.

Is this receiver set optic-ready? Yes, it is built optic-ready from the factory.

Why choose a reinforced billet upper over a standard forged one? The billet upper is structurally reinforced in critical areas for improved strength and rigidity over a standard forged design.

Buy the Radian Weapons Model 1 Builder Kit with 15.5-inch Optic-Ready Handguard

Order this Radian Weapons Model 1 builder kit from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and build on a reinforced, optic-ready billet platform. Browse our full selection of AR15 lower receivers for more build options.