I am new to the LRH forums, but have read alot of useful info in these threads.
I am with jeffro on the check your scope out.
I just had a Winchester model 70 in 270 wsm with a Leupold 4-12x40 on it that did exactly what your gun is doing,and I also have a Remington model 700 sps in 300 wsm
with a Burris fullfield 2 on it in 3-9x40 and it was doing the same thing.
I took both scopes off and sent them in to the manufactures and when I got them back and put them back on..... well sub moa @ 100 yards with both guns.