He's good at drawing intimate mounting -- hang about! (10)
I believe the answer is:
gunslinger
'he's good at drawing' is the definition.
The definition suggests a singular noun which matches the answer.
'intimate mounting hang about' is the wordplay.
'intimate' becomes 'snug' (I've seen this before).
'mounting' is a reversal indicator (going up in a down clue).
'hang about' becomes 'linger' (I've seen this before).
'snug' reversed gives 'guns'.
'guns'+'linger'='GUNSLINGER'
Can you help me to learn more?
(Other definitions for gunslinger that I've seen before include "One with a hand weapon" , "Armed bandit" , "Fighter" , "user of weapon" , "Armed cowboy perhaps" .)