Thanks chaps. When I look at One Day's picture of the mounts I think that could have been one of the issues. I had initially put the mounts on the end of the dovetail which looking back was a bad idea! We live and learn.
I was very relieved when my friend shot the rifle first at the range and placed three shots on a 2" bull at 50m. That told me things were looking up, and after a few more tries to get used to the trigger he'd pulled the groups right in. I then followed suit, my mind filled with both confidence and a feeling of "if he's shot it that well then I'll never hear the end of it if I can't!". I shot similar groups to him using up the last of my low loads and then improved on them a little with the higher ones.
I do think that a fully stoked round will be at the limit of what I enjoy regarding recoil. I expect that will improve as I shoot the rifle more - I intend in the mid term to cast and load RCBS 350gr gas checked lead bullets so I can cheaply put a lot of rounds down the rifle at informal targets. I will drive them as hard as I can tolerate and keep using the gun as regularly as I can for a while. I also have some 300gr Barnes bullets on the way which will better suit the game we have here, so will get a bit of field experience using those too.
