Rifle or pistol? (3)
I believe the answer is:
This clue is a double definition.
'rifle' is the first definition.
'pistol?' is the second definition.
(pistol is a kind of gun)
(Other definitions for gun that I've seen before include "What has barrel" , "It can be carried by 15 Ac" , "Artillery piece" , "Arm" , "Revolver" .)