My mount bolted, after shot of German weapon (5,3)
I believe the answer is:
tommy gun
'weapon' is the definition.
(Tommy gun is an example)
'my mount bolted after shot of german' is the wordplay.
'bolted' indicates anagramming the letters (bolt can mean to run around).
'after shot of' means one lot of letters goes inside another (some letters shot or injected into the word).
'german' becomes 'g' (abbreviation).
'my'+'mount'='mymount'
'mymount' is an anagram of 'tommyun'.
'tommyun' going around 'g' is 'TOMMY-GUN'.
(Other definitions for tommy gun that I've seen before include "WWII portable automatic weapon" , "Weapon named after its US designer, John T. Thompson" , "Piece" , "Light American weapon of WWII" .)