Shot guide (4)
I believe the answer is:
lead
I believe this clue is a double definition.
'shot' is the first definition.
(lead shot is a type of projectile for a gun)
'guide' is the second definition.
(lead can mean to usher or guide)
(Other definitions for lead that I've seen before include "Go in front with heavy metal" , "Actor playing the principal role" , "Take a position in front" , "Leash -- Pb" , "Soft, heavy metal" .)