Lager drinking sot performing in pieces (7)
I believe the answer is:
pistols
'pieces' is the definition.
(pistol is a kind of piece)
'lager drinking sot performing' is the wordplay.
'lager' becomes 'pils' (Pilsner beer).
'drinking' is an insertion indicator (inserted letters are consumed or drunk).
'performing' indicates an anagram (the letters move around or 'perform').
'sot' anagrammed gives 'sto'.
'pils' going around 'sto' is 'PISTOLS'.
'in' acts as a link.
(Other definitions for pistols that I've seen before include "Handguns" , "weapons" , "Guns" .)