High Quality Content by WIKIPEDIA articles! The .408 Cheyenne Tactical (or .408 CheyTac) is a specialized rimless, bottlenecked, centerfire cartridge for military long-range sniper rifles that was developed by Dr. John D. Taylor and machinist William O. Wordman. It was designed with a possible military need in mind for a cartridge for both the anti-personnel, anti-sniper and anti-materiel role with a (supersonic) precision range of 2,200 yards (2,000 m). It is hoped it will fill in a supposed market niche for long-range cartridges and is offered as a competitor to the most common military NATO long-range service cartridges .338 Lapua Magnum and the .50 BMG.