Hi White Rabbit,
I have a HW98 in .177 which I have had for a few months (not tuned) and just attached a couple of pics on the Airgunforum (thread HW98 pellets) of some 5 shot groups that I shot this morning outside in a breeze at 36 yards which you may like to look at to give you an idea what is possible for an un-tuned HW98.
Skot
Nice group there mate, what pellets are you using?