Davidson Defense Marathon w/SBA3 Brace 14.5-inch Carbine-Gas 5.56 NATO AR-15 Pistol Full Build Kit Pin/Weld Ready

The Davidson Defense Marathon 14.5" Carbine-Gas 5.56 NATO AR-15 Pistol Full Build Kit with SBA3 Brace includes everything needed for a reliable, pin-and-weld ready build. The 14.5" government profile barrel is made from 4150 CrMoV steel with a phosphate finish, 1:7 twist rate, and 1/2x28 threading—ready for the user to install and pin a muzzle device to meet the 16" legal length requirement. It features a carbine-length gas system with a 0.750 gas block for smooth cycling. The 6061-T6 aluminum upper receiver is Type III hard coat anodized, and the aircraft-grade aluminum M-LOK handguard provides durable, lightweight accessory mounting. The kit includes a nitride-finished Recoil Technologies Premium Bolt Carrier Group and an SB Tactical SBA3 adjustable stabilizing brace for improved control and handling—making it a solid foundation for a compliant, high-performance AR-15 build.