Boys anti-tank rifle. Serial #2T9516. Bi-pod in front. Vertical clip holds 5 rounds. The receiver is welded so the rifle cannot be fired. Registered in 1968 by donor. 55 caliber shells can also be used.;Marked "U.S. Gov't Property" and "R.B.M.ki.";The Rifle, Anti-Tank, .55in, Boys commonly known as the "Boys Anti-tank Rifle" was a British anti-tank rifle in use during World War II. The Boys is often incorrectly spelled "Boyes". There were three main versions of the Boys, an early model (Mark I) which had a circular muzzle brake and T shaped bipod, built primarily at BSA in England, a later model (Mk I*) built primarily at Jonathan Inglis in Toronto Canada, that had a square muzzle brake and a V shaped bipod, and a third model made for airborne forces with a 30-inch (762 mm) barrel and no muzzle brake. There were also different cartridges, with a later version offering better penetration. Although adequate against light tanks in the early part of the war, the Boys was ineffective against heavier armour and was phased out in favour of the PIAT mid-war.