RIFLING (TYPE & TWIST) – 4-Groove, Left-hand twist, 1 turn in 25.4 cm (1 turn in 10 in)
LOAD – Mk VII Composite Jacketed Spitzer
BULLET DIAMETER – 7.90 mm (0.311 in)
BULLET WEIGHT – 11.34 g (175 grains)
MUZZLE VELOCITY – 747 m/s (2450 fps)
MUZZLE ENERGY – 3163 j (2333 ft/lb)
WEIGHT (EMPTY) – 12.02 kg (26 lb 8 oz)
WEIGHT (LOADED) – 14.05 kg (31 lb) with 50 rds Mk VII Ball in pan
SIGHTS – Open, iron, adjustable, Front sight – Blade, Rear sight – Screw-ladder type with aperture
EFFECTIVE RANGE – 500 m (547 yards)
OPERATION – Gas-operated, fires from closed bolt
TYPE OF FIRE – Full automatic only
RATE OF FIRE – 100-120 rpm
CYCLIC ROF – 500-600 rpm
FEED DEVICE – 50-round pan-type drum magazine
FEED DEVICE WEIGHT (EMPTY) – 0.79 kg (1 lb 12 oz)
FEED DEVICE WEIGHT (LOADED) – 2.03 kg (4 lb 8 oz) with 50 rounds Mk VII Ball
MANUFACTURER – Armes Automatiques Lewis, S.A., Antwerp, Belgium – Birmingham Small Arms Co. Ltd., Birmingham, England
STATUS – Obsolete
SERVICE – None, demonstration-development only
This model was the original weapon produced as a production weapon for demonstration to various foreign organizations. The design proved that BSA was capable of producing the weapon, but that it needed further development. The cooling system was made smaller in diameter and the magazine capacity was reduced to 47-rounds. Most significantly, the weapon was redesigned to fire from the open-bolt position to allow for better cooling of the hot gun and a prevention of cook-off, the uncontrolled firing of a chambered round from the excess heat of the barrel. The weapon was either hand-held when fired for demonstrations, or a simple tripod was used that saw no further official service. The 50 sample weapons were produced in seven different calibers for demonstrations in Europe, the most significant being the 7.7x56mmR (303) British round, the caliber that the weapon was finally adopted in.
