Doesn't shoot the extras (6)
I believe the answer is:
spares
'extras' is the definition.
(both can mean leftovers)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for spares that I've seen before include "Replacement items, like tyres" , "Lets off; reserve parts" , "Extras in case of necessity" , "Is merciful towards, refrains from hurting" , "Extras with spears" .)