Slapstick ammo (4)
I believe the answer is:
pies
'slapstick ammo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pies that I've seen before include "Tarts" , "Pastry snacks" , "Dishes baked in pastry-lining" , "food" , "Pastry crusts with fillings" .)