How do you mean "make a difference"? Mechanically...no. Esthetically... the gap will be more pronounced. It won't effect the performance of the barrel in any way. If you are having the barreled action professionally bedded, the smith can fill and contour the barrel channel to match the varmint contour.
Did you place a custom order, or did you order from the in stock inventory. If Manners doesn't have want you want in stock, check out Stockys as they have a large inventory of Manners as well