which type of bullets were used for the gun?
Round
Lewis gun
 rounds, bullet-noses 
who is albert ball? Fighter pilot where was he born? Nottingham did he fight in any war or battle? First World War can you name any of the aircrafts that he flew? Royal Aircraft Factory B.E.2c please describe the aircraft to me A British single-engine tractor two-seat biplane designed and developed at the Royal Aircraft Factory. what kind of guns did it have? Lewis gun
wiki:11688505
Lewis gun [SEP] Design details
Only the Royal Navy retained the tube/heatsink cooling system on their deck-mounted AA-configuration Lewis guns. The Lewis gun used a pan magazine holding 47 or 97 rounds. Pan magazines hold the rounds, bullet-noses inwards toward the center, in a radial fan. Unlike the more common drum magazines, which hold the rounds parallel to the axis and are fed by spring tension, pan magazines are mechanically indexed. The Lewis magazine was driven by a cam on top of the bolt which operated a pawl mechanism via a lever. An interesting point of the design was that it did not use a traditional helical coiled recoil spring, but used a spiral spring, much like a large clock spring, in a semicircular housing just in front of the trigger.