Luth-AR FTBL-B20M .223 Rem 20" Fluted Bull Barrel Complete Upper Assembly

The Luth-AR FTBL-B20M is a complete 20" fluted bull barrel upper assembly chambered in .223 Remington. Designed to drop onto any mil-spec AR-15 lower receiver, this upper ships with the A3 flattop upper receiver, charging handle, and bolt carrier group already installed and headspaced.

The barrel is machined from 416 stainless steel in a heavy bull profile with fluting, and features a 1:9 twist rate. The added material of the bull profile gives the complete assembly a substantial weight of approximately 6.8 lbs, and Luth-AR markets this upper as a precision-shooting configuration.

Internally, the bolt is machined from Carpenter 158 steel with the extractor in 4140 alloy steel, both Army-spec heat treated and finished in manganese phosphate. The barrel carries a bare 416 stainless steel finish, while the bolt carrier group carries the manganese phosphate coating. Built for the AR-15 platform, this complete upper provides a turn-key upgrade for an existing lower receiver.