Good 'uns getting angry -- one's been fired (7)
I believe the answer is:
gunshot
'one's been fired' is the definition.
(as in firing a gun)
'good 'uns getting angry' is the wordplay.
'good' becomes 'g' (abbreviation).
'getting' is a charade indicator (letters next to each other).
'angry' becomes 'hot' (I've seen this in another clue).
'g'+'uns'+'hot'='GUNSHOT'
(Other definitions for gunshot that I've seen before include "Range of a specific weapon" , "Fire" , "Firing of hand weapon" , "One fired" , "Source of report" .)