Thanks Tegater and Snapshot, I appreciate your responses.
It's new territory for me to use a bipod regularly. I got bought a harris one for a birthday present a few years back (wifey!) and tried it on my HW100S, but I'd been a keen FT'er for years and found it more of an encumbrance. When I went up to a rimfire, range was extended certainly, but I found FT sitting position and shooting at quarry using supported shots (leaning against fences, trees etc) to suit the task well enough.
The HMR is on another level really and I am enjoying getting to grips with it. Long range sniping tool for cert