Record turning up beneath sack (7)
I believe the answer is:
plunder
'sack' is the definition.
(I know that sack can be written as plunder)
'record turning up beneath' is the wordplay.
'record' becomes 'L-P' (abbreviation for long play record).
'turning up' is a reversal indicator.
'beneath' becomes 'under' (under means beneath or underneath).
'lp' reversed gives 'pl'.
'pl'+'under'='PLUNDER'
(Other definitions for plunder that I've seen before include "Take as spoils" , "Rob" , "Loot" , "Take illegally" , "Booty" .)