The Luth-AR .223/5.56 A3 Flattop Upper Receiver Assembly (brand part no. FTT-EA1) gives builders a ready-to-use starting point for a new AR-15 build. Precision machined from a 7075-T6 aluminum forging and hardcoat anodized for a tough, scratch-resistant finish, the receiver arrives with an M4-type feed ramp, a 12-position Picatinny accessory rail for mounting scopes or flip-up sights, shell deflector, forward assist, ejection port cover, and a charging handle already installed. It is designed to accept standard AR-15 barrels, bolt carrier groups, and handguards, making it a straightforward foundation for a custom build. This is the receiver-only assembly, not a complete upper with barrel, so builders supply their own barrel and BCG.

Key Specifications

• Machined from a 7075-T6 aluminum forging for strength under repeated cycling.
• Hardcoat anodized finish resists scratching and corrosion.
• Includes an M4-type feed ramp for reliable feeding with M4-profile bolt carriers.
• 12-position Picatinny rail accepts optics and flip-up iron sights.
• Shell deflector, forward assist, and ejection port cover come pre-installed.
• Charging handle is included with the assembly.
• Machined to accept a .223 Remington/5.56 NATO barrel and bolt carrier group.

Frequently Asked Questions

Does this include a barrel or bolt carrier group? No, this is the upper receiver assembly with charging handle only; barrel and BCG are sold separately.

What material is the receiver made from? A 7075-T6 aluminum forging with a hardcoat anodized finish.

Will it accept standard AR-15 barrels? Yes, it is machined to accept standard mil-spec AR-15 barrels and components.

Buy the Luth-AR A3 Flattop Upper Receiver Assembly

Start your next AR-15 build on a durable, precision-machined foundation. Order the Luth-AR flattop upper receiver from our AR15 uppers selection, and our Lubbock, Texas team will get it shipped fast.