Well, I shot it again this weekend and took the advice of members here. Much flatter across the chest, leaning into it more, shouldered further in and there was much less discomfort. This pose does not feel as stable as the way we normally shoot and you usually end up taking a step backwards afterwards but there was no real pain like before.

I am still going ahead with a reduced load though. Seeing as I have so much 2209, I am going to just try dropping to a 450gr Woodleigh or 440gr Bertram and see how it goes for every day shooting and leave the 570gr for those that want to experience the full effect.