Luth-AR LUTH AR Rifle Kit Bull 20 w/ Adjustable Stock

The Luth-AR LUTH AR Rifle Kit Bull 20 w/ Adj Stock is a complete parts kit built around a 20-inch fluted bull barrel chambered in .223 Rem. The kit ships with a fully assembled upper including a 15 KeyMod palm handguard and an assembled bolt carrier, plus a complete LLRPK-1 lower parts kit. You may choose either the MBA-1 fixed rifle buttstock assembly or the MBA-3 adjustable carbine buttstock assembly; a stripped lower receiver is required and is not included.

Key Specifications

• The caliber is .223 Rem.
• The barrel is a 20-inch fluted bull barrel.
• The barrel material is 416 stainless steel.
• The barrel thread pitch is 1/2 x 28.
• The barrel twist rate is 1:9 right-hand.
• The bore has 6 lands and grooves.
• The handguard is a 15 KeyMod palm handguard (HG-V-15K).
• The gas block diameter is .936 inch.
• The gas tube is provided as a rifle length gas tube (BL-04).
• The kit includes a complete LLRPK-1 .223/5.56 lower parts kit and an assembled bolt carrier (BC-A-223).

This kit consolidates the core components needed to assemble a reliable rifle platform around a 20-inch fluted bull barrel, offering a straightforward path for a builder who supplies a compatible Mil-Spec stripped lower. With the choice of fixed or adjustable buttstock assemblies and an assembled upper and bolt carrier group, the kit streamlines build time while preserving flexibility for finishing and accessorizing. It is well suited for shooters seeking a stable, rifle-length gas system and the added mass of a bull barrel for consistent handling and sustained shooting applications.