Winemaker’s found with stolen ammunition (9)
I believe the answer is:
grapeshot
'ammunition' is the definition.
(historically a type of ammunition)
'winemaker's found with stolen' is the wordplay.
'winemaker's' becomes 'grapes' (I can't justify this - if you can you should give a lot more credence to this answer).
'found with' says to put letters next to each other.
'stolen' becomes 'hot' (I've seen this before).
'grapes'+'hot'='GRAPESHOT'
(Other definitions for grapeshot that I've seen before include "Charge for barrel" , "one could get peppered with it!" , "Small projectiles fired from cannon" , "Short page (anag) - ammunition for cannon" , "Small iron balls fired from a cannon" .)