Throw setter right into prison? (7)
I believe the answer is:
slammer
'prison?' is the definition.
(I know that slammer is a type of prison)
'throw setter right' is the wordplay.
'throw' becomes 'slam' (slamming is a kind of throwing).
'setter' becomes 'me' (the setter of the clue).
'right' becomes 'r' (abbreviation).
'slam'+'me'+'r'='SLAMMER'
'into' is the link.
(Other definitions for slammer that I've seen before include "one leaping into crowd" , "Prison (colloq.)" , "One pulling off lots of tricks" , "One severely criticises" , "Stir" .)