The Luth-AR 16-inch Lightweight Complete Upper (brand part no. BAA3-L16) is a ready-to-run AR-15 upper chambered in .223 Remington/5.56 NATO, built around a lightweight-profile barrel machined from 4140 chrome-moly steel. The 16-inch barrel carries a 1-in-9 twist rate for reliable stabilization across common .223/5.56 bullet weights, and it mates to an A3 flattop receiver that arrives with bolt carrier, charging handle, forward assist, and ejection port cover already installed. A low-profile gas system and 15-inch ergonomic palm handguard with KeyMod slots and a Picatinny top rail keep the package light and accessory-ready. It is a straightforward way to finish a carbine build without sourcing and fitting individual upper parts.

Key Specifications

• Chambered in .223 Remington/5.56 NATO for broad ammunition compatibility.
• 16-inch lightweight barrel keeps the completed rifle balanced and maneuverable.
• Machined from 4140 chrome-moly steel for durability at a lighter weight than stainless bull barrels.
• 1-in-9 twist rate stabilizes common .223/5.56 bullet weights.
• A3 flattop receiver arrives with bolt carrier, charging handle, forward assist, and ejection port cover.
• Low-profile gas system preserves a clean sight plane for optics.
• 15-inch KeyMod handguard with full-length Picatinny top rail for mounting accessories.
• Sold as a complete, ready-to-install upper assembly.
• A3 flattop design accepts standard optics and flip-up sights without an adapter.

Frequently Asked Questions

Is this upper ready to shoot out of the box? Yes, it arrives fully assembled with bolt carrier, charging handle, and handguard installed.

What barrel material does it use? 4140 chrome-moly steel, chosen for durability at a lighter weight than stainless.

What twist rate does it use? A 1-in-9 twist for common .223/5.56 bullet weights.

Buy the Luth-AR 16-inch Lightweight Complete Upper

Get a lighter-weight carbine upper without hunting down individual parts. Order the Luth-AR 16-inch lightweight upper from our AR15 uppers selection, and our Lubbock, Texas team will get it shipped fast.