Material used to increase velocity of a pistol shot (7)
I believe the answer is:
topsail
'material' is the definition.
(topsail is a kind of material)
'a pistol shot' is the wordplay.
'shot' indicates anagramming the letters.
'a'+'pistol'='apistol'
'apistol' is an anagram of 'TOPSAIL'.
'used to increase velocity of' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for topsail that I've seen before include "sheet of canvas" , "Uppermost attachment of a vessel's rigging" , "Highly-placed canvas" , "Part of a ship's rigging" , "Part of ship's canvas" .)