The McMillan TAC-50 is a long-range anti-materiel rifle. The TAC-50 is based on previous designs from the same company, which first appeared during the late 1980s. From May 2017 until November 2023, it held the record for the longest confirmed sniper kill. McMillan makes several .50 caliber rifles, based on the same proprietary action, for military, law enforcement and civilian use. It is produced in Phoenix, Arizona, in the United States by McMillan Firearms Manufacturing.

An anti-materiel rifle (AMR) is a rifle designed for use against military equipment, structures, and other hardware (materiel) targets. Anti-materiel rifles are chambered in significantly larger calibers than conventional rifles and are employed to eliminate equipment such as engines and unarmored or lightly armored targets. While modern armored vehicles are resistant to anti-materiel rifles, the extended range and penetration still has many modern applications. Although not intended for use against human targets, the bullet weight and velocity of anti-materiel rifles gives them exceptional long-range capability even when compared with designated sniper rifles. Anti-materiel rifles are made in both bolt-action as well as semi-automatic designs.