Gets gun broken into pieces (7)
I believe the answer is:
nuggets
'pieces' is the definition.
(nugget is a kind of piece)
'gets gun broken' is the wordplay.
'broken' indicates an anagram.
'gets'+'gun'='getsgun'
'getsgun' anagrammed gives 'NUGGETS'.
'into' acts as a link.
(Other definitions for nuggets that I've seen before include "Small lumps of gold" , "Lumps of metal like gold" , "Solid lumps of a precious metal" .)