I went through the same thing with my 06. That's how I ended up with the NightForce then the new stock.
Check the mounts/rail make sure they/it's not loose. Make sure the scope rings are tight to rail and at the scope (LockTite is your friend). Make sure the action screws are torque properly and if the barrel is free-floated that it does contact the stock when on whatever you are using for a rest. When was the last time it got a good cleaning? Copper fouling will also cause a rifle to loose accuracy. I would hope the smith checked all of that for you before telling you to change scopes.
It went from shooting like this at 100 yds. That's a 1" circle.
To shooting like this. That's a 1/2" diamond top to bottom side to side. The low one was cause by the loose nut on the back end of the rifle.