Stringing shots help

[swebb38]

What would be an unusual cause of stringing shots vertical and right by several inches...Ive checked scope and mounts and stock for cracks. Im working up a new load and was wondering if different seating depths can cause a gun to shoot off by 5 inches or so. I normally seat .35 off and on this new load I backed them up a bit more, but Ive never had a load string them this bad....no pressure signs at all....

 

[britz]

I have played w/ seating depth in my wsm. I was surprised to find that changing the seating depth (.1" incraments or more) caused the groups two shift a few inches at 100 yards. But I doubt if a couple thou's would produce that result. Is your rifle bedded? Action screws tight? Did you check the bullet Runout?