The Boys Mk I Anti-Tank Rifle is a united kingdom-made bolt-action rifle chambered in .55 Boys, introduced in 1937. Primary use: hunting, sport. Type: Rifle Action: Bolt-Action Caliber: .55 Boys Capacity: 5 Year introduced: 1937, United Kingdom Weight: 112 oz Overall length: 44" Status: Discontinued Military use: Yes Intended use: hunting, sport