Bloody Mary shot Russian soldiers (3,4)
I believe the answer is:
red army
'soldiers' is the definition.
(army of the USSR)
'bloody mary shot russian' is the wordplay.
I cannot really understand how this works, but
'bloody' could be 'red' and 'red' is found in the answer.
an anagram of 'mary' is 'army' which is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for red army that I've seen before include "Revolutionary fighters" , "force" , "Left soldiers" , "Soviet troops" , "Leon's offensive baby" .)