Hitting with metal (3)
I believe the answer is:
tin
'metal' is the definition.
(I know that tin is a type of metal)
'hitting with' is the wordplay.
'with' indicates the answer is hidden within the clue.
'TIN' is hidden within 'hitting'.
(Other definitions for tin that I've seen before include "Money" , "roofing material" , "Metal in Argentina" , "Canister" , "Silver-white element often used in food containers" .)