CODE 03-131-937
NAME – Boys 55 Mark I
NAME (NATIVE) – Rifle, Anti-tank, 0.55 in Boys Mk I
COMMON NAMES – Boys 55, Elephant Gun
COUNTRY OF ORIGIN – Great Britain
DATE OF MANUFACTURE – 1937
CALIBER – 13.9x99mmB
OVERALL LENGTH – 162.6 cm (64 in)
BARREL LENGTH – 91.4 cm (36 in)
RIFLING (TYPE & TWIST) – 7 Grooves, Right hand twist, 1 turn in 25.4 cm (10 inches)
LOAD – Full metal jacketed armor piercing
BULLET DIAMETER – 14.27 mm (0.562 in)
BULLET WEIGHT – 60 g (926 grains) Mark I
MUZZLE VELOCITY – 761 m/s (2495 fps)
MUZZLE ENERGY – 17,357 j (12,802 ft/lb)
WEIGHT (EMPTY) – 16.10 kg (35 lb 8 oz)
WEIGHT (LOADED) – 17.22 kg (37 lb 15.4 oz) loaded with 5 rounds Mk I AP
TYPE OF MOUNT – Attached Monopod
SIGHTS – Open, Iron, adjustable. Front sight – Square blade, Rear sight – Aperture, Adjustable for 274 or 457 meters (300 or 500 yards)
EFFECTIVE RANGE – 274 meters (300 yards)
OPERATION – Manual, bolt action
TYPE OF FIRE – Repeating
RATE OF FIRE – 9 to 10 rpm
FEED DEVICE – 5 round removable top-feed box magazine, Single column, Single feed
FEED DEVICE WEIGHT (EMPTY) – 0.46 kg (1 lb 0.3 oz)
FEED DEVICE WEIGHT (LOADED) – 1.12 kg (2 lb 7.5 oz) loaded with 5 rounds Mk I AP
BASIC AMMUNITION LOAD – Eight 5-round magazines (40 rounds)
LOAD WEIGHT – 8.88 kg (19 lb 9.2 oz)
TRANSPORT CASE WEIGHT (EMPTY) (For 8 Magazines) – 2.89 kg (6 lb 6 oz)
TRANSPORT CASE (LOADED) – 11.77 kg (25 lb 15.2 oz) with 8 loaded 5-round magazines (40 rounds)
MANUFACTURER – Royal Small Arms Factory, Enfield (Designer/developer), Birmingham Small Arms, Birmingham, John Inglis and Co, Toronto, Canada
STATUS – Obsolete
SERVICE – Military forces of Great Britain, Australia, and Canada along with their allies. Very limited use by the United States Marine Corps Raider Battalions
