The Radian Weapons R0898 Model 1 is a complete AR-platform upper chambered in 6mm ARC, built around a 14.5-inch black nitride steel barrel. It’s sold as an upper only, with no lower receiver included.

Key Specifications

• Complete upper, chambered in 6mm ARC
• 14.5-inch barrel
• Black nitride steel barrel finish
• Sold as an upper only, no lower receiver included
• Part of Radian’s Model 1 upper lineup
• Compatible with mil-spec AR-15 pattern lowers
• Steel barrel construction
• Chambered specifically for the 6mm ARC cartridge

Frequently Asked Questions

Does this upper come with a lower receiver?
No, it’s sold as an upper only. An AR upper without a serialized lower isn’t a firearm by itself.

Can I put this on any AR-15 lower?
Putting it on a shouldered rifle lower makes a short-barreled rifle; since October 9, 2026, ATF no longer requires Form 1 approval or registration for that, but state law still applies, and taking an SBR across state lines needs an approved ATF Form 5320.20. Confirm your configuration is legal before assembly.

Buy the Radian Weapons Model 1 Complete Upper

Build out a 6mm ARC upper with a complete assembly from Radian Weapons. Ships fast from a Lubbock, TX gun shop in our AR15 uppers lineup.