Ransack mountains where there is much shooting (5,5)
I believe the answer is:
rifle range
'where there is much shooting' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'ransack mountains' is the wordplay.
'ransack' becomes 'rifle' (rifle can mean to ransack or rob).
'mountains' becomes 'range' (range of mountains).
'rifle'+'range'='RIFLE-RANGE'
Can you help me to learn more?
(Other definitions for rifle range that I've seen before include "army training ground" , "One-cell microorganism" , "firearms in practice here" , "How far one might go to steal" , "butts" .)