Bother with gun for problem-solver (14)
I believe the answer is:
troubleshooter
'solver' is the definition.
(I've seen this before)
'bother with gun' is the wordplay.
'bother' becomes 'trouble' (synonyms).
'with gun' becomes 'shooter' (I've seen this before. I am not sure about the 'with' bit.).
'trouble'+'shooter'='TROUBLESHOOTER'
'for problem' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for troubleshooter that I've seen before include "One trying to solve problems" , "A solver of problems" , "One tracing and correcting faults" , "He may fix problem" , "Problem fixer" .)