Bristol has eight 319s and three 320s.
A glance at next week's Mayfly - see this link
Next Week's Mayfly | Bristol Airport Intranet
will show that the 320s are used on a wide range of routes, and not necessarily the same ones each day.
For instance on Monday of next week the 320s are allocated to the following routes:
Edinburgh
Murcia
Dalaman
Geneva
Berlin Schoenfeld
Funchal
Corfu
Prague
Edinburgh
The first and last EDI rotations of the day are 320s with the evening one being an EDI-based aircraft.