Bigstick- no wind to speak of, Leupold dovetail mounts. First 2 shots were 1/2" from center of a 1.5" dot, moved 1 click, next 3 shots were 4" left.
I'm not a huge fan of dovetail mounts (rings/bases). I do have some, and they work if on a light kicker and the rings not turned in and out of the bases more than a time or two.
I bought a limited edition Model 70 Featherweight for a real deal not long ago. The original owner that sold it said he was glad to get rid of it-- was junk and wouldn't shoot. So I paid the asking price and headed home. I removed the Tasco and started to remove the rings when I noticed the front ring nearly fell out it was so loose when I touched it. Installed Tally lightweights, my VXIII that I had laying around and went to shooting. The rifle proceeded to place 3 of my initial loads inside an inch at 100 meters and into 1 1/2 inches at 200 meters.
It does sound like your scope took a crap or is way too far into horizontal adjustment, but check the rings to be sure they are tight when turned into the bases (if you have not). If you have addressed this already, forget I posted...
