Burst of gunfire (5)
'burst of gunfire' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for salvo that I've seen before include "Simultaneous discharge of weapons" , "Rounds delivered" , "Succession of shots" , "Round of fire" , "Ceremonial round of gunfire" .)
(Other definitions for fusillade that I've seen before include "salvo" , "shot series?" , "Barrage (of shots)" , "Continuous discharge of fire" , "Rapid series of shots" .)