Ham trimmed at the edges is what soldiers need (4)
I believe the answer is:
ammo
'the edges is what soldiers need' is the definition.
I can't judge whether this defines the answer.
'ham trimmed' is the wordplay.
'ham' becomes 'gammon' (synonyms).
'trimmed' indicates the central letters (the external letters are trimmed from the word).
The central letters of 'gammon' are 'AMMO'.
'at' acts as a link.
Can you help me to learn more?
(Other definitions for ammo that I've seen before include "eg Bullets, shells" , "Bullets, shells (colloq.)" , "Bullets (sl.)" , "What's fired from guns (abbr)" , "Bullets, shells, rockets etc" .)