They say that old dogs can't be taught new tricks, however this one could certainly acquire some bad ones.
Range day yesterday with an old colleague of mine who has 20yrs experience as a trained marksman on the Accuracy International 7.62 police sniper rifle. I don't know why I didn't think of asking him for help before but better late than never.
The only 'kit' problem was to get rid of the neoprene comb-raiser as it was not required and putting too much pressure on the comb. ( as advised on SD)
The main problems were with my technique. Incredibly (when shooting off sticks but not with bags) I was snatching a breath at the point of firing the shot ! I couldn't believe it! That was causing me to snatch the trigger and produced the same sort of result as a flinch may do. I didn't do it every shot but most. I was also unconsciously putting my finger on and off the trigger as I aimed ! Terry had a rather rude but funny similie for that one.
Another problem when shooting off the sticks was my stance, particularly in keeping both legs locked straight and bending my back but not a knee.
By the end of the session I was able to stop my bad habits and put the shots where I was aiming at 100 yds off both bags and sticks. I was absolutely knackered by the intense instruction and concentration. It was a very pleased knackered though.
So now its lots of practice with the rimfire to embed the lessons. Never too old to learn and awareness is so important to achieving resolution. Many thanks to all SD members who offered your thoughts and help.