Is it a wood stock? Could be your stock has picked up some moisture/oil and swelled the wood causing pressure on the bbl.

Just ran into this problem with a new Ruger Hawkeye in .257 roberts. It was actually shifting the action in the stock. Swelled so tight I broke 2 good quality hollowground gunsmith screwdrivers trying to get it out of the stock.

The other advice is great as well. Could be scope mounts. Could be scope, could be you. I have had days that I felt fine and couldn't hit a bull in the butt, let alone the "eye". One way to tell is to let someone else shoot it.

Good Luck