The Barrett M82 is one of the premier sniper rifles ever manufactured. Now in its fourth decade of service, the semiautomatic rifle fires a .50-caliber BMG round (the same round used in the Browning M2 machine gun) and is capable of delivering devastating results over more than 2km. Unconfirmed reports from Afghanistan in 2012 suggest that the Barrett holds the record for history's longest sniper kill: 2,815m.

This is the technical history of a rifle that was initially designed as an antimateriel rifle, created to destroy enemy vehicles and parked aircraft, but which has been adopted as a sniping rifle by fifty nations and has been used in the First Gulf War, in Iraq and Afghanistan, and by Malaysian special forces and Indian Police commandos and special forces units.

The firing experience of using the Barrett (the detonation is akin to that of a small artillery piece), and the explosive impact of the round, have also made the gun a cultural icon, appearing in numerous films and video games and being sold to an eager civilian market. As one of the most extraordinary guns of the last fifty years, the Barrett will continue to cast its shadow over the battlefield for many years to come.

Chris McNab has published more than forty books, including A History of the World in 100 Weapons and has written for many publications. He lives in South Wales, United Kingdom.

Johnny Shumate is a freelance illustrator in Nashville. His greatest influences are Angus McBride, Don Troiani, and Edouard Detaille.

Alan Gilliland, a photojournalist and cartoonist, won nineteen awards as the graphics editor of The Daily Telegraph. He now publishes fiction (www.ravensquill.com), and illustrates (www.alangilliland.com).