Go ballistic without the bits of sound (7)
I believe the answer is:
logical
'sound' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for logical that I've seen before include "Clearly and soundly reasoned" , "Objective" , "In accordance with reason" , "Deducible" , "Using reason" .)