Fire assault rifle with live round (4)

I believe the answer is:

bake

I'm a little stuck... Click here to teach me more about this clue!

'fire' is the definition.
(thesaurus)

I can't explain the rest of the clue.

(Other definitions for bake that I've seen before include "Roast" , "Cook in a hot oven" , "Cook (eg, bread)" , "Cook by dry heat in an oven" , "Cook cake or bread" .)

I've seen this clue in The Sunday Times.

Want a hint initially instead of a full solution? Install my app