I took a Tikka BA in trade and planned on rebarreling it. I decided to see what it would do before taking it apart.
pic is not uploading for some reason but 5 shot group was around 0.25. I guess that’s not good.
If it’s stringing that perfectly and consistently I’d guess the scope internals or mount is not holding. Try screwing the windage way out (so there is the least pressure on the spring) and aim where you will still land on paper. See if you get anything different.