Score nothing when shot out! (5)
I believe the answer is:
shoot
'score' is the definition.
(I know that shoot is a type of score)
'nothing when shot out' is the wordplay.
'nothing when' becomes 'o' (I can't explain this - if you can you should believe this answer much more).
'out' is an insertion indicator.
'o' placed inside 'shot' is 'SHOOT'.
Can you help me to learn more?
(Other definitions for shoot that I've seen before include "Fire (a gun)" , "Make a film" , "modelling session" , "New growth; last word of Hamlet" , "country sport" .)