Fire rifle (4)
I believe the answer is:
sack
I believe this is a double definition.
'fire' is the first definition.
(dismiss someone from their job)
'rifle' is the second definition.
(I've seen this before)
(Other definitions for sack that I've seen before include "Elbow" , "Dismiss; plunder; wine" , "Get rid of" , "Plunder - dry white wine - dismissal" , "Fire the large bag?" .)