Not if your into consistancy, new brass is made to factory spec tolerance, that means it's +/- size within a given range. Once fired, form's itself to your chamber. Now new brass has to be fired anyways to form, but, I will FL size any new brass I get before I load and fire the first time just to make them all the same as my die and rifle.
Others milage may very,,
Our local sporting goods store (the only one that stocks re-loading goods) has about 6 guy's that reload and are available for ?'s, I can get 3 different views on just about any topic I ask about loading