I just had a quick check, the book I was reading does show the straighter or more relaxed right leg. Rifle Shooting as a Sport by Bernd Klingner 1980.

It must've been from the articles I had been reading and the way a few other club members shoot which got the 45-90 degree leg position into my head, although thinking about it the only guy who averages high 90's also uses a straighter right leg position.

What i'd got in my mind was that the right leg should lift he body slightly to take weight off the chest, i'm quite a big guy though so by trying to do that i'm putting quite a bit of pressure onto my leg and it is trying to fall back level, this was also causing me to roll into the right arm putting a lot of pressure through the right hand which I know is wrong. I spent some time taking my right hand on and off the grip to ensure the sights weren't moving.

So actually the problem was reading articles from unknown sources and looking at what the lesser shooters were doing!