I am guessing you are using this gun for hunting. You could just dial in the scope for the cold shot.
When I sight in my hunting gun I always wait 30 minutes between each shot.
Although, when I only wait 1 minute I've never had a gun that is off 2", that is a lot!
Some people do crazy things trying to fix this, including freezing barrels. It could make you lose your mind. Could be less frustration to get a new gun.