RE: "Accurizing" a new gun to shoot tighter??
As your post said that it was a Remington XCR, I assume that it has a composite stock?
This being the case, you can sand on the inside of the forend or evenuse a dremel on it to remove more material. You can do this yourself as you don't have to worry as much about damaging the forend like you would with a wood stock. On the composite forends, fairly straigtforward and easily made to float.