Introduced in 2000, this rifle is chambered for the 50 BMG cartridge. The upper left side of the receiver is marked with the Armalite logo followed by "AR-50A1" and the serial number and is fitted with a Picatinny rail topped with a Nightforce ATACR 5-25x56 scope. The left side of the barrel is marked ".50 BMG" and it is equipped with the proprietary Armalite designed muzzlebrake. Single stage trigger, textured rubber pistol grip and mounted in an aluminum chassis.