Luth-AR FTBL-B24M 24" Fluted Bull Barrel 223 Rem / 5.56 NATO Complete Upper

The Luth-AR FTBL-B24M complete upper assembly is built around a 24-inch fluted bull barrel chambered in 223 Remington / 5.56 NATO, and ships ready to drop onto any mil-spec AR-15 lower receiver.

The barrel is machined from 416 stainless steel with a 1:9 twist and 5R rifling for improved accuracy and easier cleaning. An M4 feed ramp supports reliable feeding, while the fluted profile trims overall weight and helps the barrel shed heat during extended strings of fire. The barrel mates to an A3 flattop upper receiver that accepts any standard AR-15 picatinny-mounted optic or rear sight, and the assembly is compatible with a rifle-length gas system.

Inside, the upper is completed with an 8620 steel bolt carrier, a 4130 alloy carrier key, and a 4340 chromoly cam pin, all finished to military heat-treat specifications for long service life. A 15" KeyMod handguard fits around the bull barrel profile and provides generous rail real estate for lights, lasers, bipods, and forward grips.

The FTBL-B24M is a turnkey solution for builders assembling a long-range, varmint, or DMR-style AR-15 platform.