Weekdays:
0821 Paddington to Hereford
1021 Paddington to Hereford
1721 Paddington to Hereford
1821 Paddington to Hereford
0543 Hereford to Paddington
0643 Hereford to Paddington
1311 Hereford to Paddington
1511 Hereford to Paddington
2153 Hereford to Paddington
Saturdays:
0711 Hereford to Paddington
1311 Hereford to Paddington
1511 Hereford to Paddington
2153 Hereford to Paddington
0821 Paddington to Hereford
1021 Paddington to Hereford
1821 Paddington to Hereford
Sundays, the first train towards Worcester is normally HST, there's also a 1630 Hereford to Paddington I believe, possibly also 2030 Hereford to Paddington, but the rest I'm not sure on.
Bear in mind the above all used to be HST, but I've not looked at the new timetable properly yet. As The Exmoor Beast says, they do sometimes put Turbos on vice HST, most common on those to Great Malvern/Worcester. The 2059 Worcester to Paddington is most regularly Turbo vice HST in particular. As he also says, if there's heavy delays on the Oxford to Worcester section, it's quite regular to turn back early at Ledbury/Great Malvern/Worcester, although in all fairness I've not seen this happen in quite some time. Most probably due to the much more sensible turnaround times at Hereford these days.
Good luck getting a HST and enjoy the trip
