The record is between 100 and 500 (4)
I believe the answer is:
disc
'the record' is the definition.
(eg a CD, compact disc)
'is between 100 and 500' is the wordplay.
'between' indicates putting letters inside.
'100' becomes 'C' (Roman numeral).
'and' is a charade indicator (letters next to each other).
'500' becomes 'D' (Roman numeral for 500).
'c' after 'd' is 'dc'.
'is' going into 'dc' is 'DISC'.
(Other definitions for disc that I've seen before include "Back part" , "something moving in the spine" , "Flat thin circular body" , "Spine cartilage layer" , "Flat round plate" .)