Friz,
I agree, sounds like hunching down on the rifle, almost like shooting prone.

Best to sit more upright.
For heavy magnums we use the rule " back straight and belly touching the bench." Takes about 6 to 12 sandbags which really makes you " look different" -- don' t care. If they won' t let you use more sand bags then bring your own.

Sit upright, get that thing sighted in and get off of the bench!
EKM

I don,t do much shooting with high power rifles anymore until its gets near deer season. The first time out each fall I get a big bruise and a Black and blue area on the shoulder. This, no matter what I do. After a few weeks it goes away and does not bruise again until the next year. When I was shooting steel silhouettes with the 308, I never got sore because I quess it was toughened in from the constant battering. Keep the bench shooting to a minumum because thats where you really get nailed. I do some shooting all year with my 22 to keep in shape for shooting. The bad shoulder that I have is to a big degree from shooting to many big rifles to much. So says my doctor anyway. I don,t doubt it because I used to shoot a couple hundred rounds a week through some big rifles. The big offender was my Ruger NO.1 416 Rem Mag. That one got your attention right now. Of course I was young and tough and not to smart then. Now I am smarter or CHICKEN.