Search through to get the gun (5)
I believe the answer is:
rifle
I believe this clue is a double definition.
'search through' is the first definition.
'the gun' is the second definition.
(rifle is a kind of gun)
'to get' acts as a link.
(Other definitions for rifle that I've seen before include "Root" , "Gun; thoroughly search" , "shoot?" , "Strip - firearm" , "Gun with long_barrel" .)