The Browning Automatic Rifle (BAR) was brought by the Destroyermen, and Denis Silva's favorite rifle early in the series. Most likely the M1918A2. See Wikipedia for more information: https://en.wikipedia.org/wiki/M1918_Browning_Automatic_Rifle
Specifications M1918A2: Weight 8.8 kg (19 lb), Length 1,194 mm (47.0 in) Barrel length 610 mm (24.0 in)
Cartridge .30-06 Springfield
Action Gas-operated, rising bolt lock, Rate of fire 500–650 rounds/min, Muzzle velocity 860 m/s (2,822 ft/s) Effective firing range 100–1,500 yards (91–1,372 m) sight adjustments (maximum effective range) Maximum firing range Approx. 4,500–5,000 yards (4,100–4,600 m) Feed system 20-round detachable box magazine, Sights Rear leaf, front post