Charge for firearms (10)
I believe the answer is:
ammunition
'charge for firearms' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'charge' is the wordplay.
I cannot really see how this works, but
'charge' could be 'ion' (an ion is a charged particle) and 'ion' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ammunition that I've seen before include "Bullets, eg" , "Points used to advantage" , "Bullets and shells" , "shot" , "possibly in magazines" .)