Sacks out in barrels (5)
I believe the answer is:
casks
'barrels' is the definition.
('cask' can be a synonym of 'barrel')
'sacks out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'sacks' anagrammed gives 'CASKS'.
'in' acts as a link.
(Other definitions for casks that I've seen before include "Barrel-shaped containers for liquids" , "vessels" , "lots of beer" , "Large barrels" .)