Bullet casing with raised line found on barrow? (9)
I believe the answer is:
cartridge
'bullet casing' is the definition.
(a cartridge contains a bullet and a charge)
'raised line found on barrow?' is the wordplay.
'raised line' becomes 'ridge' (a ridge is a raised line or edge).
'found on' means one lot of letters go next to another.
'barrow?' becomes 'cart' (barrow is a kind of cart).
'ridge' after 'cart' is 'CARTRIDGE'.
'with' acts as a link.
(Other definitions for cartridge that I've seen before include "Tube of ink for fountain pen" , "Casing for charge and bullet" , "Sort of paper" , "stunning charge may be made" , "Bullet's casing" .)