This is the best short answer.
Medium length answer: For the same bullet weight, case, propellant, primer, ambient weather conditions, propellant temperature combination, you may see some slight increases in pressure, but it is generally not sufficient to get excited about, unless you are going from a 1-14 to 1-7 (even then I doubt any difference would show up without a pressure test rig). Big things that effect pressure are chamber dimensions, number of lands and grooves and the proportion of land width the groove width, forcing cone angle, seating depth.
