Maybe it's me and I'm crazy but here's my story. I have a 300 wby ultralight that 's never been a great shooter--not awful either but I'm trying to get better 300 yd groups with it. OK, it's an ultralight which is a risky proposition to start with. But the other day at the range I noticed on my ballistic plex (Burris fullfield II)scope at 300 yds that depending on where I position my head and eyes the cross hairs seem to wander with my eye position. I'm shooting at 5" orange dots with a black center and can see the center pretty clear. But by moving my head around I can make the crosshairs move almost all the way around that 5" dot. (This being done with a solid fron rest and rear sandbag holding the gun virturally rock solid). I checked one of my Leupolds when I got home and I swear it doesn't move hardly at all---maybe an inch if I really move out of position behind my scope. If what I think is happening ....IS happening ...this certainly can't be good for shooting good groups. I'm thinking this is what they call "parralax"?? Anyhow has anyone else experienced this with their fullfield II or are my 48 year old eyes going bad??