Gun volley (5)
I believe the answer is:
salvo
'gun volley' 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 "Outburst, as of applause" , "Rapid simultaneous shooting" , "concentrated fire" , "Firing of guns as a salute" , "A volley of shots, perhaps as salute" .)